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  • Articles  (1,001)
  • Chemistry  (1,001)
  • 1980-1984  (1,001)
  • 1980  (1,001)
  • Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics  (1,001)
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  • Articles  (1,001)
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  • 1980-1984  (1,001)
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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 1-13 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The influence of hydroxyl modifiers on the properties of Diels-Alder adducts-terpene hydrocarbons with maleic anhydride - was studied. The mechanical, thermal, and dielectric properties of the composition of Epidian 5 epoxy resin hardened with an adduct modified by ethylene glycol, propylene glycol, dipropylene glycol, glycerin, or hexanetriol are described.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 41-49 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Helium gas plasma treatment of low-density polyethylene (LDPE) yields much lower peel strength than oxidative treatment using chromic acid and oxygen gas plasma. The practical adhesion, the bondability retention, and the bond durability of oxidatively treated LDPE sheets, bonded with epoxy adhesives, have been compared with those of partially hydrolyzed LDPE-methyl acrylate surface grafts. The oxidized surfaces easily lose the bondability by light rubbing with tissue paper, solvent extraction, heat aging, and artifical weathering, whereas the grafted surfaces retain the bondability. The bondability loss is due to removal of the oxidized layer, and the bondability retention is due to retention of the surface homopolymer layer. Conventional antioxidants stabilize the grafted but not the oxidized surfaces against thermal oxidative degradation. The grafted LDPE joints have much higher bond durability in humid environments than those of the oxidized LDPE joints. The dry and wet peel strengths of oxidized LDPE joints are greatly improved by application of primers consisting of a base epoxy resin and organic solvents. An adhesion mechanism involving penetration of epoxy adhesives into the oxidized layers and subsequent reinforcement of the layers by curing of the penetrated epoxy is proposed.
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  • 3
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Glow discharge initiation of in situ polymerization of acrylic acid and other vinyl monomers incorporated in PET films was investigatigated. The influence of glow discharge conditions such as the gas used, plasma power, discharge current, and plasma treatment time on polymerization yield was determined. Though glow discharge effects are limited to the film surface, in situ polymerization of the vinyl monomers took place and the vinyl polymer could be found all through the film cross section. At short plasma treatment time only surface modification took place, while at longer treatment time bulk modification occurred, too. Good polymerization yields were obtained. Gel effect behavior was observed. Mechanical properties of the modified PET film were not changed, while the contact angle with water improved when polar vinyl monomers were used.
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 127-137 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A study of postextrusion relaxation (shrinkage) rates identified two separate processes, only one of which is influenced by carbon black structure and surface area. One of these processes is thought to be a solidlike fast elastic recovery and was found to be influenced by carbon black and polymer characteristics. The other process reflected slow randomization of oriented molecular chains: it was mainly influenced by polymer nature and carbon black had almost no effect. In the previous paper of this series, work with various carbon blacks in SBR-1500 indicated that both types of polymer deformation originate within the converging flow region at the die entrance, where extensional flow takes place. In the present work the extensional flow behavior of five polymers (filled with various carbon blacks) was examined at elevated temperatures. The magnitude of shrinkage caused by molecular alignment was related to extensional viscosity of the rubbers. This confirms the hypothesis stated above. Extensional viscosity was measured using the previously described instrument, which is inexpensive to construct, easy to operate, and can be attached to any standard stress-strain tester. The characteristics of extensional flow are defined and it is shown that for polymeric materials it differs substantially from shear flow, since a rapid orientation of the molecular chains takes place during the extensional flow. The effect of carbon black on the extensional viscosity at elevated temperatures is illustrated.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 111-118 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Effect of temperature on the electrical conductivity of PVC-copper composites has been studied. The temperature coefficient of dc resistivity of composites with fillers containing negligible oxide content in the range of 77-303 K is positive, indicating metallic-type conduction. The temperature coefficient of dc resistivity of composites with fillers containing intermediate level of oxide at higher temperatures is negative, indicating a semiconducting behavior. Plots of log conductivity versus log frequency for composites in the insulating region show the hopping-type conduction.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 25-39 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Adhesive joints of hydrolyzed methyl acrylate grafts, bonded with epoxy adhesives, yield extremely high peel strength (adherend failure) in dry conditions. However, when the joints are exposed to humid environments, the peel strenght rapidly decreases with exposure time and then reaches a constant value (wet peel strength). Since the locus of failure changes from the adherend to the homopolymer layer with decreasing peel strength, the decrease is due to a decrease in mechanical strength of the homopolymer layer itself, which results from its swelling by water absorption. Many attempts to reduce the swelling of the homopolymer layer or to strengthen the swollen homopolymer layer were unsuccessful except (1) priming with epoxy solutions consisting of a base epoxy resin and organic solvents which can dissolve not only epoxy resins but also hydrolyzed poly(methyl acrylate) and (2) partial etching of the homopolymer layer by photo-oxidative degradation. All the results on the improvement in wet peel strength can be explained in terms of the penetration of epoxy resins into the homopolymer layer and subsequent curing of the penetrated epoxy resin.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 15-23 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The effect of orientation on the structure and transport properties of high-density polyethylene film has been studied. Microstructure was characterized using small-angle light scattering, birefringence, and wide-angle x-ray scattering. Water vapor and oxygen transmission rates were determined as a function of film draw ratio. The object of the present work is to correlate the effects of postprocessing conditions on the transport properties and morphology of linear polyethylene. High-density spherulitic polyethylene films were produced by blown film extrusion and subsequently oriented by longitudinal stretching in a postoperation. Various degrees of orientation were imparted to the films, with percent crystallinity, sample orientation and transport properties measured as a function of draw ratio. For the postoriented films, results indicate there was no significant change in percent crystallinity with increasing draw ratio although water vapor and oxygen permeability decreased substantially. This is attributed to the increased orientation of the crystalline and amorphous regions and rod-like and microfibril structure formation brought about by the drawing process. Lower processing temperatures result in increased orientation which improves the vapor barrier properties.
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  • 8
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Graft copolymerization of methyl methacrylate onto wool was investigated in aqueous solution using potassium peroxydiphosphate as initiator. The rate of grafting was determined by varying monomer, peroxydiphosphate ion, temperature, solvent, and nature of wool. The graft yield increases with increase in monomer concentration. The graft yield increases significantly by increasing peroxydiphosphate ion up to 80 × 10-4mole/l.; with further increase of peroxydiphosphate ion the graft yield decreases. The rate of grafting increases with increase in temperature. The effect of acid-and water-soluble solvents on the rate of grafting was investigated and a suitable rate expression has been derived.
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 433-447 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Changes in the dynamic mechanical properties of nylon 6 (α-form) under ultraviolet light irradiation were investigated. On irradiation with spectrally dispersed ultraviolet light in the wavelength range of 219-415nm, the dynamic modulus E′ and the density of nylon 6 were increased below about 300nm. It was found that the increment in E′ and the density were the result of crosslinking. When E′ was measured with time elapsed during irradiation by light of 253.7 nm, E′ initially decreased with time, increased at a longer time, and then reached a limiting value asymptotically. From the result of the change in E′ with time, it was assumed that the scission and crosslinking reactions occur simultaneously during ultraviolet light irradiation. Thus, the change in E′ with elapsed time was exppressed by the equation E′t = E′0 exp (-k1t) + E′∞[1 - exp (-k2t)], where E′t is the dynamic modulus at time t, E′0 is the E′ at t = 0, E′∞ is the limiting value of E′, and k1 and k2 are the rate constants. The apparent activation energies for k1 and k2 were 3.23 and 2.50 kcal/mole, respectively, and the former value agreed with the activation energy for the scission of the amide groups. The effects of the photodegradation on the temperature dispersion of nylon 6 were also investigated. On irradiation with light at 253.7 nm, the α-relaxation which appeared at about 90°C was broadened and the intensity of the γ-relaxation at -95°C in the tan δ-versus-temperature curve was lowered. The β-relaxation which appeared at -45°C for the wet nylon 6 decreased its intensity.
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  • 10
    Electronic Resource
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 499-510 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Several physical methods were used for the determination of the mean molecular weight of polyethylene glycols (PEG). Gas chromatography proved to be the best method to obtain a molecular weight of PEG lower than 600 by using Tenax as a stationary phase. Reverse gas chromatography was long but valid for PEG between 400 and 3000. Viscosity measurements gave more suitable values by taking different Mark-Houwink constants according to the molecular weight of PEG. Gel permeation chromatography using the universal calibration method was shown reliable, and by means of three μ-Styragel phases (100, 500, and 104 Å) the molecular weight range between 200 and 20,000 was covered. Infrared measurements were related to the molecular weight by taking the OH absorbing band, and a result for PEG of 5000 or less was obtained. Vapor pressure measurements as made in tonometry were an accurate and sensitive method.
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  • 11
    Electronic Resource
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 529-534 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The Rheovibron viscoelastometer is useful for obtaining dynamic tensile, shear, and bending mechanical properties of films and fibers over a wide teḿperature range. In recent years a modification that makes measurement on materials in a liquid or gas medium possible has been reported. A new compression grip and procedure were used for measuring dynamic mechanical properties of a fiber mass in the compression mode using the Rheovibron instrument. The dynamic compression properties on nylon, polyester, and acrylic fibers are presented.
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  • 12
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Many UV-cured acrylates, epoxides, and thiol-enes suffer a dramatic, reversible loss of tensile strength during exposure to moisture and/or elevated temperatures. Certain formulations are especially sensitive and lose up to 95% of their dry tensile strength in a humid environment. Glass transition temperatures of these materials are also much lower in high humidity than they are in low humidity. It is proposed that these losses of physical properties in high humidity are due to reduced intersegmental attractions of polymer chains caused by preferential hydrogen bonding to water.
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  • 13
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 575-588 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: As part of a continuing study of nonisothermal rheology (meaning the simultaneous application of strain and temperature changes), we here consider the behavior of polystyrene near the glass transition temperature Tg. In particular, we measured the increase of the apparent Tg as the cooling rate is increased from 0.003 to 4.5°C/sec. This change (up to 16°C increase) has both practical and theoretical implications. For enhancing the mechanical properties of a glassy product, one desires maximum orientation (stress) just prior to quenching; the optimum deformation/temperature strategy for maximizing stress is affected by the level of Tg. By using a nonisothermal strategy we were able to produce higher frozen-in orientations, and thus higher mechanical properties, than have been previously reported. For a theoretical understanding of the rubbery state just prior to quenching, we used the generalized time-temperature superposition of our prior work; we found that a modified shift factor of the form aT(T,TRg), where TRg refers to a rate-dependent Tg, gives an improved fit to data but is not by itself adequate.
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  • 14
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 615-625 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Certain aspects of moisture sensitivity for selected polyurethane-polyether block copolymers were investigated. Exposure to ambient conditions tended to raise the impact velocity for projectile penetration and to decrease the brittleness of these materials. High values of relative humidity, whether applied immediately or after a time delay, led to softening and ductile response of an initially brittle formulation. Immediate desiccation of the brittle formulation caused retention of hardness and brittleness, whereas after prior humidification, desiccation removed much water but did not reverse the prior transition to ductile response to impact. Measurements were made of water sorption and desorption exhibited by this brittle formulation.
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  • 15
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 683-689 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Cellulose peroxides derived from hydrogen peroxide and cellulose derivative into which a ketone group is introduced by reaction with methyl vinyl ketone were investigated. The amount of peroxide formed on the cellulose substrate increased linearly with increasing carbonyl content of the sample, and sulfuric acid activated the formation of peroxide. The cellulose peroxide was gradually decomposed at 60°C in aqueous medium, and the decomposition was accelerated by addition of ferrous salt or irradiation with light of λ 〉 300nm. Grafting was initiated by adding methyl methacrylate to the thermal decomposition system under nitrogen. The formation, stability, thermal decomposition, and structure of the cellulose peroxide were discussed in comparison with one derived from aldehyde cellulose and hydrogen peroxide.
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  • 16
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 711-716 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 5 Ill.
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  • 17
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 739-746 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Several polyurethanes were prepared from poly(ethylene adipate)glycol, 4,4′-diphenylmethane diisocyanate, 1,4-butanediol, or 3,3′-dichloro-4,4′-diaminodiphenylmethane. Thermomechanical curves were determined for all investigated systems, and the glass transitions found thereof formed the basis of subsequent analysis. The analysis showed that the investigated systems belonged to those polyurethanes that can undergo microphase separation. It was also shown that the separation in the diamine-extended elastomers was less sensitive to changes in chemical composition than in the diol-extended systems. The diamine-based polyurethanes were also closer to the ideal separation than the diol-extended elastomers. Examinations of elastomers of varying amount of chemical crosslinking revealed a joint action of the crosslinking and microphase separation in determining mechanical properties of the systems. Together with swelling measurements, the examinations showed that optimum mechanical properties were obtained while keeping a very careful balance between these two factors.
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  • 18
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 761-769 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The influence of relative molecular weight on rubber thermo-oxidation in air at 130 ± 1°C has been studied by means of infrared spectroscopy. The carbonyl group formation in single fractions of natural rubber has been measured. It was found that the development of kinetic curves ΔAC=O = f(t) corresponds for both fractionated and unfractionated extracted samples. Kinetic curves of natural rubber formation are characterized by an induction period τ. Its magnitude is a function of molecular weight up to the value [η] = 0.2 m3/kg, and then stays invariant to changes in [η]. In the range of low values of the internal viscosity up to 0.2 m3/kg, the dependence τC=O = f[η] has an exponential character as a consequence of the statistical character of chains breaking down during the degradation. It has been proved that the reciprocal value dependence of the mean viscosity molecular weight of unfractionated acetone-extracted natural rubber on the length of induction period is linear. The change in double-bond amount during the oxidation is not reflected in the induction period determined by infrared spectroscopy.
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  • 19
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 795-807 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: In discontinuous fiber-reinforced composites, the shear strength at the fiber-matrix interface plays an important role in determining the reinforcing effect. In this paper, a method was devised to accurately determine this shear strength, taking the strength distribution of glass fiber into consideration. Calculated strength values based on the shear strenght obtained by the method were in better agreement with the experimental observations than those calculated by employing the shear strength obtained on the assumption that the fiber strength was uniform. The tensile strength of composites increases with increasing aspect ratio of the reinforcing fibers. This trend is almost the same regardless of the kind of matrix, the nature of interfacial treatment, and the environmental temperature. When composites are reinforced with random-planar orientation of short glass fibers of 1.5 times the mean critical fiber length, the tensile strength of composite reaches about 90% of the theoretical strength of composites reinforced with continuous glass fiber. Reinforcing with glass fibers 5 times the critical length, the tensile strength reaches about 97% of theoretical. However, from a practical point of view, it is adequate to reinforce with short fibers of 1.5-2.0 times the mean critical fiber lenght.
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  • 20
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    Journal of Applied Polymer Science 25 (1980), S. 635-640 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The lateral order factor of four Indian varieties of silk, viz., Mulberry, Tasar, Eri, and Muga, were determined by electron diffraction technique and compared with that determined by x-ray diffraction. The profiles of the 002 and 201 reflections in Mulberry were better resolved by the electron diffraction technique.
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  • 21
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    Journal of Applied Polymer Science 25 (1980), S. 665-682 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The network segment density (γg) by solvent-swollen compression modulus of gum stocks and of stocks containing nonreinforcing fillers was calculated to be 6.6093 × 10-9h0Sf/φBd2 in mmole/m3 of gel at 25°C, where h0 is the height of the unswollen sample in cm, S is the slope of the height versus applied weight curve in g per mil (0.001 in.), φB is the volume fraction of binder, d is the diameter of the initial sample in cm, and f is a factor equal to (1- φs/φB)1/3/(1- φS)2/3, where φS is the volume fraction of extract. The volume fraction of crosslinked polymer containing nonreinforcing fillers at equilibrium in a solvent (V2) was determined for the cases where the filler is insoluble and partially adheres to the binder, where the filler is partially solube and there is no binder-filler adhesion, and where the filler is completely soluble in the swelling solvent. The relations were tested and found to hold for polyester-polyurethane stocks containing plasticizer and soluble and insoluble fillers. Log V2 fell on single straight-line curves with respect to log γg for gum stocks and filled stocks both when V2 was measured in solvents which dissolved none or dissolved part of the fillers.
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  • 22
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    Journal of Applied Polymer Science 25 (1980), S. 691-702 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Thermal analysis of cotton samples grafted with triallylphosphate (TAP) and 2,2,2-tribromoethyl acrylate (TBEA) was carried out. Grafting of poly-TAP causes a significant decrease in the decomposition temperature of cotton. The cotton decomposition is acid catalyzed by H3PO4 formed during the decomposition of the grafted poly-TAP. The HBr evolved during decomposition was monitored continuously during thermal analysis of cotton grafted with poly-TBEA. No significant flame-retarding effect by HBr was found. Since grafted poly-TBEA causes a decrease in the decomposition temperature of cotton, it is suggested that the flame retardant mechanism for poly-TBEA in cotton occurs mainly in the solid phase before most of the HBr is released.
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  • 23
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    Journal of Applied Polymer Science 25 (1980), S. 731-738 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The ability of adsorbing iodine in different organic solutions by chitosan was studied by sorption isotherm measurements. The ability was found to be larger in polar solvents than in nonpolar solvents. The form of the chitosan samples, such as film, powder, and flake, had no influence on the adsorption behavior. On the other hand, chitin had only small adsorbing ability of iodine. It is concluded that the adsorption of iodine is caused by charge - transfer complexes between aminogroups of chitosan and iodine molecules, but their structure differs from that of inclusion compounds as seen in amylose-iodine complexes. The adsorption was also studied on chitosan films with different degrees of acetylation.
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  • 24
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    Journal of Applied Polymer Science 25 (1980), S. 747-759 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Thermolysis and hydrogenolysis of polyethylene under steam pressure were carried out by batchwise autoclave in the recovery of liquid petrochemical resources from waste polymers. Thermolysis of polyethylene under steam pressure occurred in the temperature range 400-475°C and reaction pressures up to 213 bar. The presence of steam is advantageous for an increase in liquid products and 450°C is an appropriate temperature for the formation of low molecular aromatic compounds. Hydrogenolysis of polyethylene was studied at 450°C and initial hydrogen pressure range of 10-100 bar under steam pressure. Over 80 wt % of the low-boiling product was converted to saturated hydrocarbons at 40 bar hydrogen pressure, which corresponds to 1 mole hydrogen to 1 mole monomeric unit of polyethylene. The schemes for the thermolysis and the hydrogenolysis, especially the aromatization, are discussed.
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  • 25
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    Journal of Applied Polymer Science 25 (1980), S. 841-854 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The study of the effect of sodium poly(styrene sulfonate) addition to suspensions of fibers, in the presence of aluminum salts as adsorption aids, revealed the retention effect of fine solids during sheet formation. Polyelectrolyte adsorption also causes an increase of bounding energy in the web. It is shown that the improvement observed for the dry strength properties of paper is a consequence of these two effects. (In this paper the words “fine solids” or “fines” indicate the parts of the cellulosic material which filtrates through a 150-mesh screen, regardless of its nature.)
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  • 26
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    Journal of Applied Polymer Science 25 (1980), S. 1049-1058 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Molecular weight distributions, moments and the polydispersity indices were computed for AB-type condensation polymerization in an ideal continuous-flow-stirred tank reactor for monomers not following the equal reactivity hypothesis. The model considers the rate of reaction between monomer and monomer to be R times that characterizing the reaction between any other species in the reaction mass. It is found that the polydispersity indices in these reactors are substantially larger than values obtained in batch reactors. Also, the molecular weight distribution splits into two curves - one for odd-order homologs and the other for even-order ones for R 〉1. For R 〈 1, substantial amounts of unreacted monomer are present in the exit stream, and curve splitting does not occur.
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  • 27
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    Journal of Applied Polymer Science 25 (1980), S. 1087-1094 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Thermal behavior of graft copolymers of polyvinyl chloride with polystyrene prepared by using a cationic initiator (AlCl3) was evaluated by measurement of rates of dehydrochlorination in nitrogen atmosphere. With increase in the extent of grafting the rates were found to decrease. Dynamic thermogravimetric analysis revealed an overall improvement in thermal stability of copolymers. Development of polyene sequences in degraded polymer samples was evaluated by measurement of electronic absorption spectra. In comparison to PVC, graft copolymer samples had fewer conjugated double bonds.
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  • 28
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    Journal of Applied Polymer Science 25 (1980), S. 1095-1104 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: In our previous article on the photodegradation of polypropyle (PP), the effect of ferric chloride (FeCl3) accelerating the formation of peroxy radical and depressing the formation of alkyl radical were reported. In the present article, the influence of FeCl3 on model compounds of PP was examined using electron spin resonance (ESR) spectrometry. The following compounds were employed as models of PP, including its irregular structures: 2-methylpentane (2-MP), 2,4-dimethylpentane (2,4-DMP), 2-methyl-4-pentanone (2-M4P), 2,6-dimethyl-4-heptanone (2,6-DM4H), 2-methyl-1-pentene (2-M1P), and tert-butylhydroperoxide (t-BuO2H). FeCl3 accelerated the formation of alkyl radicals for 2-MP and 2,4-DMP, alkyl and acyl radicals for 2-M4P and 2,6-DM4H, and alkyl radicals for 2-M1P. As no definite effect of FeCl3 was observed for n-pentane and 2-octanone, FeCl3 was assumed to attack saturated hydrocarbons, ketones at a tertiary carbon-hydrogen bond, and hydrocabons at an allylic hydroge, leading to easier photodegradations. FeCl3 was also effective for the photodegradation of t-BuO2H using λ 〉300 nm, so that FeCl3 is believed to contribute also to the photodegradation of PP under the same irradation conditions. The catalytic effect of FeCl3 in photodegradation seems to origirate in a redox reaction.
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  • 29
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    Journal of Applied Polymer Science 25 (1980), S. 1145-1155 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Compositional analysis of 2,6-dimethyl-1,4-phenylene oxide (PPO) and styrene homopolymer blends was accomplished using infrared spectrometry and pyrolysis gas chromatography. In infrared measurements the 1030/700 cm-1 absorption ratio provides percent PPO in the blends within ±3% of the actual value but with a σ% of ±10. In pyrolysis GC measurements, four peaks resulting from the fragmentation of the PPO molecule have been investigated for quantitation. One of these peaks provides results with ±2% of the PPO present with a σ% of 7 when the percent PPO in the blend is above 20.
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  • 30
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    Journal of Applied Polymer Science 25 (1980), S. 1263-1271 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The influence of hydrofuramide (a reaction product of furfural and ammonia) on the network structure and overall kinetics of thiuram vulcanization of natural rubber is reported. The nature of the network structure of the thiuram vulcanizates in the presence and absence of hydrofuramide was determined using triphenyl phosphine (Ph3P) as a chemical probe. The presence of hydrofuramide produces structural complexity of the vulcanizate. The overall kinetics of thiuram vulcanization follows a first-order-rate law in the presence as well as in the absence of hydrofuramide. The rate constant increases while the energy of activation decreases in the presence of hydrofuramide.
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  • 31
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    Journal of Applied Polymer Science 25 (1980), S. 1217-1244 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: An experimental study of the viscosity and principal normal stress difference of a polystyrene melt filled with aramid (Kevlar), glass, and cellulose fibers is reported. The influence of loading level and mastication on the rheological properties is discussed. The effects of mixing and mastication on fiber damage are considered. Glass fibers break down rapidly to very small aspect ratios, while aramid shows a “kinked” structure, with kinks occurring every 100 μm. A mechanism is proposed for fiber breakage based on buckling during rotation in shear flow. It is found that addition of fibers increases the viscosity in the same manner as a reduction in temperature, and data may be superposed by reduced plotting. This indicates that the viscosity increase is due solely to enhanced viscous dissipation in the matrix and not to interparticle forces as is the case with smaller particles. The principal normal stress difference increases at fixed shear stress with fiber loading. The extent of increase depends upon fiber loading, aspect ratio, and modulus.
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  • 32
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    Journal of Applied Polymer Science 25 (1980), S. 1673-1684 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Dielectric, x-ray diffraction, density, thermomechanical, and thermogravimetric studies on polyacrylonitrile (PAN), poly[acrylonitrile-(2 methacryloyloxy)ethoxytrimethylsilane] [poly(AN-2MAETMS)], and poly[acrylonitrile-(2 methacryloyloxy)propoxytrimethylsilene] [poly(AN-2MAPTMS)] copolymers have been carried out for investigating their structure. The glass transition temperature as indicated from the dielectric and thermomechanical analysis data are lower for the copolymers as compared to PAN. Crystallinity is influenced by the introduction of the silylated acrylic comonomer units but the crystalline lattice remains similar to that of PAN. The changes obseved in the various properties of these coplymers clearly suggest a more closely packed structure of poly(AN-2MAETMS) than poly(AN-2MAPTMS), and the uninterrupted PAN sequences are longer in the former. Thermal stability of copolymers has also been investigated.
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  • 33
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    Journal of Applied Polymer Science 25 (1980), S. 1655-1671 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Biodegradative conversion of 14C present in high-density (linear) polyethene (HDPE) film to respiratory 14CO2 during a two-year aerated cultivation with soil or with Fusarium redolens dropped from 0.36% by weight to less than 0.16% by weight when the HDPE film was deprived from most of its low molecular components by extraction with cyclohexane. Decrease of 14CO2 production after extraction could be observed in different abiotic aging cultures. This is direct evidence for a primary utilization of the short-chain oligomeric fraction of the main crystalline materials. The extractable oligomeric fraction of HDPE was analyzed by gel permeation chromatography (GPC), and Mn 1049, 1088, and 1297 were found in untreated, aged, and biodegraded materials, respectively, indicating that microbes can oxidize somewhat longer polyolefin chains than aboitic forces do during aging. The limited degradation of HDPE confined to extractable material is comparable to the degradation of straight-chain n-alkanes and presumably proceeds according to similar mechanism. Such material (n-alkanes) can exit in the interstitial spaces between the crystalline lamellae as fringed micelles which infiltrate these cavities as amorphous clusters but are also produced to some extent during aging and weathering. Protection of HDPE by antioxidant (a sterically hindered phenol) resulted in an inhibition of microbiological catabolism of 14C to 14CO2. Aging was also suppressed in this way, indicating that although remnants of the supported CrCO3 polymerization catalyst are responsible for a slight but cumulative abiotic oxidation of the unprotected polymer, this effect will be counteracted too by the antioxidative additive. As biological degradation is superimposed on the chemistry of aging, a mutual synergism between the two effects is feasible.
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  • 34
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    Journal of Applied Polymer Science 25 (1980), S. 1703-1713 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The tensile behavior of blends of linear polyethylene (PE) and isotactic polypropylene (PP) was examined in relation to their morphology. Yield stress increases monotonically with increasing PP content, while true ultimate strength is much lower in all blends than in the pure polymers as a result of early fracture. The blends fail at low elongation because of their two-phase structure, consisting of interpenetrating networks or of islands of PE in a PP matrix, as shown by scanning electron microscopy of fracture surfaces and transmission electron microscopy of thin films. While spherulites in PP are very large (∼100 μm in diameter), addition of 10% or more of PE drastically reduces their average size. This, together with the profusion of intercrystalline links introduced by PE, may be associated with maximization of tensile modulus in blends containing ∼80% PP. Introduction of special nucleating agents to PP reduces average spherulite size and is accompanied by slight improvements in modulus. Thin films of blends strained in the electron microscope neck and fibrillate in their PE regions, but fracture cleanly with little fibrillation in areas of PP.
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  • 35
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    Journal of Applied Polymer Science 25 (1980), S. 1745-1753 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Heat treatment of nylon 6,6 in the temperature range of 100-175°C in the presence and absence of a nonionic surfactant (Triton X-100) had little effect on the physical properties of the nylon, although the density of the nylon increased with increasing heat treatment temperature. The moisture regain value for the treated nylons did not change substantilly, whereas the overall wettability of the heat-treated nylon in the presence of nonionic surfactant showed a marked improvement. Both heat treatment of the nylon alone or in the presence of surfactant had a substantial effect on the uptake of three 1,4-substituted anthraquinone dyes on the nylon and on the resultant color of the dyed nylon.
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  • 36
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    Journal of Applied Polymer Science 25 (1980), S. 1755-1774 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The permeabilities and diffusivities of methane, ethane, propane, n-butane, and isobutane in commercially available poly(tetrafluoroethylene) (TFE) and poly(fluoroethylene-propylene) (FEP) Teflon have been measured in a Pasternak-type permeation cell. Experiments were carried out at upstream hydrocarbon partial pressures up to 50 torr (1000-60,000 ppm gas phase concentration) and temperatures from 40 to 195°C with films of 0.0508 and 0.127 mm thickness using nitrogen as carrier gas on the upstream and downstream sides of the membrane. The transient and steady-state permeation data are described well by a combination of Henry's law and Fick's law with a concentration-independent diffusion coefficient. Linear Arrhenius plots of both permeabilities and diffusivities were obtained. Linear correlations were found both between the activation energy for diffusion and the square of the gas molecule diameter, and between the logarithm of solubility at 90°C and the penetrant boiling point. Separation factors for binary mixtures of hydrocarbons were measured for TFE at 140°C and found to be similar to those predicted by individual permeabilities in most cases. Measurements with mixed gases were not made for FEP Teflon, but selectivities of FEP are expected to be similarly well described by the ratios of the pure gas permeabilities at the low partial pressures studied. The effect of annealing FEP Teflon for 24 hr at 200°C was found to produce an average of 20-30% reduction in solubility as well as a 9% increase in the activation energy for diffusion compared to as-received films. These effects are believed to be due to increased crystallinity in the sample upon annealing.
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    Journal of Applied Polymer Science 25 (1980), S. 1789-1792 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
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  • 38
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    Journal of Applied Polymer Science 25 (1980), S. 1799-1806 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
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  • 39
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    Journal of Applied Polymer Science 25 (1980), S. 1825-1831 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A method is developed to estimate the composition of a powder mixture using breadths of over-lapping x-ray diffraction (XRD) lines. The application of the method is illustrated for analyzing blends of cotton and jute.
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  • 40
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    Journal of Applied Polymer Science 25 (1980), S. 1839-1859 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The pyrolysis of organic waste polymers to produce fuels and chemicals is of interest to augment petroleum-based processes. The wide variety of pyrolysis products of low yield and the uncertain role that heat transfer rate plays in determining these have been deterrents to utilization in the past. A possible approach to increased selectivity for products is to heat them rapidly and homogeneously with the aim of narrowing the product distribution. A very rapid means of homogeneous heat transfer throughout the substrate is microwave heating. A laboratory study has been done to determine what effect high-intensity microwave energy has on the thermal degradative pathways of cellulose. The product distribution found when cellulose is pyrolyzed in the absence of a microwave discharge is similar to that found in conventional furnace pyrolysis. The major products are levoglucosan (27%), carbon dioxide (2-5%), water, and charred residue. However, the total heat-up and reaction times for even large pellets are reduced to less than 2-3 min when high-intensity microwave irradiation is employed. Effects of pressure and microwave power are reported. Low external gas temperature also prevents secondary reactions.
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  • 41
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    Journal of Applied Polymer Science 25 (1980), S. 1861-1866 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The tensile strength and ultimate strain of polypropylene fibers were measured by the creep fracture method at various temperatures. The tensile strength against time-to-break curves at various temperatures, which were plotted on log-log scales, were superposed by shifting the curves along the logarithmic time-to-break axis, and the composite curve of the tensile strength as a function of a reduced time to break was obtained. On the other hand, to construct the composite curve of ultimate strain from the ultimate strain against time-to-break curves at various temperatures, shifting the curves along the logarithmic ultimate strain axis was required in combination with shifting along the logarithmic time-to-break axis. The temperature dependence of the shift factor aT followed an equation of the Williams-Landel-Ferry (WLF) form. The volume fraction of free volume at the glass transition temperature and the coefficient of thermal volume expansion, which were calculated from the WLF coefficients determined for the polypropylene fibers, are almost the same as those known as “universal values” for amorphous polymers.
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  • 42
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    Journal of Applied Polymer Science 25 (1980), S. 1931-1942 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Processes aimed at forming high-performance fiber morphologies from rigid, semirigid, and flexible polymers have been analyzed. Routes that rely at least partially on the favorable thermodynamic consequences of conformational rigidity imparted by intramolecular and polymer-solvent interactions are shown to offer much greater promise than those that rely entirely on externally applied deformation.
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  • 43
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    Journal of Applied Polymer Science 25 (1980), S. 1943-1950 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: On the basis of standards of identification of substances in the additive system of polyethylene has been performed. Different methods for separation such as adsorption thin-layer chromatography, high-performance liquid chromatography with chemically bounded phases, and gas chromatography have been used. The fir al identification has been made with mass spectrometry. The substances have been extracted from polyethylene with hexane and chloroform.
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  • 44
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    Journal of Applied Polymer Science 25 (1980), S. 1969-1989 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The preparation of a novel asymmetric membrane cast from a homogeneous mixture of poly(4-vinyl pyridine) and cellulose acetate is described. The two polymers were found to be compatible in the presence of Lewis acids, yielding hydrophilic homogeneous alloys when properly prepared. Asymmetric membranes were cast from a six-component dope mixture containing chloroform, methanol, acetone, and formamide. The as-cast solution, when coagulated in water at ambient temperature, yields a highly plasticized anisotropic matrix which solidifies into a glassy state as the chloroform slowly diffuses into the water. The membranes, following this stage, exhibit a semipermeable dense skin that produces high fluxes and salt rejections when tested in a high-pressure reverse osmosis mode (no annealing is required). The anisotropic morphology was confirmed by scanning electron microscopy studies which revealed a dense skin resting on a highly porous, open-celled foamlike structure. This structure does not collapse upon drying and retains its original wet dimensions. Brief attempts to quaternize the matrix are also reported.
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  • 45
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    Journal of Applied Polymer Science 25 (1980), S. 1723-1735 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Effect of sorbed water on dielectric and mechanical properties is studied for three kinds of polyion complex (PIC) membranes formed from equal moles of polyanion [poly(sodium 4-vinylbenze-sulfonate)] and three polycations of different structural isomerisms [poly(4-vinylphenethyltriethylammonium bromide), poly(3-vinylphenethyltriethylammonium bromide), and random copolymer of these monomers]. Sorption isotherms and swelling characteristics indicate that PIC of parapolycation includes more water microphases than PIC of meta-polycatio. Complex dielectric constants of three PICs with varied water contents are measured at frequencies from 10 Hz to 100 kHz and the relaxation is analyzed in terms of the heterogeneous structure. Stress-elongation relationships of PICs equilibrated with water and aqueous NaBr indicate that yield and break stresses are higher for PIC of meta-polycation than that of para-polycation and decrease with increasing NaBr concentration above 0.1M.
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  • 46
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    Journal of Applied Polymer Science 25 (1980), S. 1775-1780 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Operation of an improved design of a vapor pressure osmometer for polyolefins at 140°C is described. Reproducibility of ±10% of the measured number-average molecular weight (Mn) was obtained with a maximum Mn of about 45,000-50,000. Results are reported for some standard and commercial, linear and branched polyethylenes and for commercial polypropylenes.
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    Journal of Applied Polymer Science 25 (1980), S. 1785-1788 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Journal of Applied Polymer Science 25 (1980), S. 1813-1813 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
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    Journal of Applied Polymer Science 25 (1980), S. 1875-1882 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The chemical structure of polyurethane modified by BHET is correlated with its mechanical and dynamic mechanical properties. Evaluation of this amorphous elastomer by means of stress-strain tests and transition temperature measurements reveals that incorporation of the BHET structure into the soft polyester segment affects the domain structure and, in turn, the entire mechanical behavior of polyurethane. It is also shown that polyurethane has a wide range of Tg and secondary transition temperature by varying the ratio of BHET to EG as well as the ratio of TDI to polyester polyol.
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  • 50
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    Journal of Applied Polymer Science 25 (1980), S. 1961-1968 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Films of poly(methyl methacrylate) (PMMA), polystyrene, and a styrene/acrylic terpolymer have been cast from solutions of varying thermodynamic quality and the film properties studied by inverse gas chromatography and by critical surface tension measurements. Surface properties of the non-polar polystyrene were independent of solvent medium, but significant variations in these properties were observed in the case of PMMA and the terpolymer. Solvent balance also appeared to affect the bulk properties of the latter films, as judged by the penetration rates of interacting liquids. The observations indicate the feasibility of controlling film properties of the solid by the appropriate selection of solution media; a time-dependent variation in solid properties is to be expected, however, as the film structure attains an equilibrium state.
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  • 51
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    Journal of Applied Polymer Science 25 (1980), S. 2007-2017 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Europium(III) chelates of dibenzoylmethane (DBM) (1) and β-diketone-containing polymers, i.e., poly(p-benzoylacetylstyrene) (2) and poly(aryl β-diketone) (3), were prepared. In the polymer 2 the β-diketone moiety is attached to the phenyl ring, and for polymer 3 the β-diketone group is incorporated in the linear chain. The chelate structures were confirmed by measuring IR spectra, TGA, and DTA. The fluorescence emission intensity was measured on fine powder samples. For the composite samples of Eu(DBM)4 in polystyrene, the fluorescence intensity was found to increase linearly with increasing Eu content. However, for Eu coordination polymers, the intensity reached a maximum at Eu3+ content as small as 1 wt % and remained constant on further increasing the Eu3+ content. When the fluorescence intensities of Eu complexes were compared under the same conditions, namely, 1 wt % Eu, at which Eu-2 and Eu-3 show nearly maximum intensity, the order was found to be Eu-1 〉 Eu-2 〉 Eu-3. These phenomena were accounted for by the differences in the coordination number of the Eu complexes.
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  • 52
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    Journal of Applied Polymer Science 25 (1980), S. 2105-2107 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Fibrillar size of native cellulose was studied in detail by electron microscopic and x-ray techniques. Samples included natural fibers of cotton and ramie as well as algal and bacterial celluloses. Results indicated smaller sizes for cotton and ramie than was previously reported in the literature and a possible difference in fibrillar sizes among celluloses.
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  • 53
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Kinetic data are reported for the fast polymerization of a thermoplastic polyurethane under conditions similar to that of commercial reaction injection molding (RIM). The components were a 2000 molecular weight polyester polyol, butanediol and 4,4′-diphenylmethane diisocyanate. Three catalysts-dibutyltin dilaurate, phenyl mercuric propionate, and triethylenediamine-as well as uncatalyzed formulations were studied. Kinetic parameters were obtained by numerically fitting adiabatic temperature rise data with both second-order and hyperbolic models. The hyperbolic model gave consistently better fits and is supported by mechanistic studies in the literature. Activation energies compare well to literature values. The uncatalyzed rate was found to be significant. The kinetic parameters obtained by this method are useful measures of catalyst performance in the RIM systems. Moreover, the models provide a conveient way to predict the extent of reaction during the production of parts by the RIM process. The shape of the reaction pathway (extent of reaction time) may be important in the development of physical properties of polymers produced by the RIM process. Physical properties for these samples compare favorably to those for a conventionally produced (batch) polyurethane of the same formulation.
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    Journal of Applied Polymer Science 25 (1980), S. 2363-2372 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: In a study of polyacrylamide in solutions we have required the rapid characterization on chromatographies. The application to the aqueous solution of the GPC using controlled-porosity glass has been examined from both the viewpoint of the effect of salt addition and the GPC mechanism. An adequate addition to neutral salt, 0.005M KCI to the eluent, gave rise to the elution behaviors being in accord with the hydrodynamic volume concept of the GPC separation.
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  • 55
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    Journal of Applied Polymer Science 25 (1980), S. 2435-2438 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
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  • 56
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    Journal of Applied Polymer Science 25 (1980), S. 2649-2652 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
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  • 57
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    Journal of Applied Polymer Science 25 (1980), S. 2657-2657 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
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  • 58
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    Journal of Applied Polymer Science 25 (1980), S. 2699-2710 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Moisture-cured polyurethanes were prepared by reacting toluene diisocyanate and sebacic acid-based hydroxy esters such as ethylene glycol sebacate, propylene glycol sebacate, diethylene glycol sebacate, and polyester polyols such as poly(ethylene glycol sebacate), poly(propylene glycol sebacate), poly(diethylene glycol sebacate), and poly(butane diol sebacate). The effect of molecular weight of the esters on film properties and the catalytic effect of 3-5% triethylamine, triethanolamine, and 2-diethylaminoethanol on curing of such films were investigated. Polyurethanes were also prepared using a blend of poly(butane diol carbonate) polyol with polyester polyols. Best polyurethane compositions were obtained when sebacic acid-based polyester polyols were blended with poly(butane diol carbonate) polyol in the ratio of 3:2. These polyurethanes show good tensile strength (120-215 kg/cm2) and elongation (340-460%) properties, having high melting points (247-268°C) and good resistance to solvents and chemicals. Moreover, they are colorless and transparent.
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  • 59
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    Journal of Applied Polymer Science 25 (1980), S. 2285-2294 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A series of C4-C12 alkyl acrylates and methacrylates was polymerized with starch by irradiating starch-monomer mixtures with 60Co. Homopolymers were extracted with cyclohexane. The amounts of insoluble versus soluble synthetic polymer in polymerization run with alkyl acrylates varied less with the chain length of the alkyl substuent than in the polymerizations run with alkyl acrylates varied less with the chain length of the alkyl substituent than in the polymerizations run with alkyl methacrylates; and the poly(alkyl acrylate) contents of cyclohexane-insoluble fractions were all in the 38-45% range. Synthetic polymer contents of the products from butyl, hexyl, and decyl methacrylates were also close to this range. Octyl and lauryl methacrylate, however, gave high conversions to cyclohexane-soluble poly(alkyl methacrylate) along with little or no unextractable synthetic polymer in the starch-containing fractions. Poly(lauryl methacrylate) could be rendered insoluble by incorporating a small amount of tetramethylene glycol dimethacrylate in the polymerization mixture. In a series of polymerizations run with hexyl acrylate and hexyl methacrylate, lower irradiation doses led to more cyclohexane-soluble polymer and less synthetic polymer in the starch-containing fractions. Enzymatic digestion of starch-soluble polymer and less synthetic polymer in the starch-containing fractions. Enzymatic digestion of starch-containing polymers gave synthetic polymer fractions that were largely insoluble in cyclohexane. Crosslinking is, therefore, probably taking place during these polymerizations; however, we could not eliminate the possibility that reduced solubility was caused by small amounts of residual carbohydrate in these polymer fractions. Ceric ammonium nitrate-initiated polymerizations of butyl acrylate, hexyl acrylate, and butyl methacrylate with starch gave cyclohexane-insoluble polymers that contained 33-39% synthetic polymer. The higher alkyl acrylates and methacrylates produced little or no polymer under these conditions. Starch-containing fractions were tested as absorbents for hydrocarbons. Products prepared from decyl acrylate and lauryl acryle acrylate absorbed about 9 g of isooctane per 1 g of polymer, whereas the lowrer alkyl monomers gave polymers with lower absorbency.
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  • 60
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Tribological Properties of Chemically Deposited Ni-P-Coatings and Ni-P-SiC Composite CoatingsChemical deposition of Ni-P-coatings is a standard coating technique in surface treatment. The coatings have good corrosion resistance and good tribological properties due to their relatively high hardness. By codeposition of ceramic particles (SiC) these properties can be improved.
    Notes: Chemisch (stromlos) abgeschiedene Nickel-Phosphor-Schichten gehören zu den Standardbeschichtungen der funktionellen Galvanotechnik. Die Schichten sind weitgehend korrosionsbeständig und besitzen durch ihre hohe Härte gute tribologische Eigenschaften. Durch Mitabscheidung keramischer Hartstoffpartikel (SiC) können diese Eigenschaften noch weiter verbessert werden (1).Solche Dispersionsschichten haben bereits wichtige Anwendungsgebiete z. B. in der Textilindustrie und Kunststoffverarbeitung (Glasfasergehalte) gefunden und dort z. T. zu erheblichen Standzeitverbesserungen von Werkzeugen bis zum Faktor 15 geführt (2).Sehr häufig werden die Schichten nicht nur durch Verschleiß, sondern gleichzeitig auch durch Korrosion beansprucht, z. B. durch reaktive chemische Agenzien, die während des Spritz- bzw. bei Duroplasten während des Vernetzungsvorganges in Kunststofformwerkzeugen entstehen können.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 82-92 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: By means of the inclusion of a dispersed phase with low Young's modulus, the generally low thermal stress resistance of brittle materials for high-temperature structures can be improved significantly. An analysis of this improvement on the basis of continuum and micromechanical theory is presented in this paper.The low-E phase is shown to cause a significant decrease in Young's modulus, with a negligible effect in the coefficient of thermal expansion. The relative change in thermal conductivity is a function of the thermal conductivity of the dispersed phase.The tensile fracture stress is reduced significantly, primarily due to the mismatch in elastic properties, with smaller effects due to the mismatches in the coefficient of thermal expansion and thermal conductivity.The relative changes in Young's modulus and tensile fracture stress are such as to result in an increase in the strain-at-fracture and a simultaneous decrease in the elastic energy at fracture, the driving force for catastrophic crack propagation. The accompanying increase in fracture energy also contributes to the improvement of thermal shock resistance. By changing the size of the low-E inclusion, tradeoffs can be made between strain-at-fracture and elastic energy at fracture.
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  • 62
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 92-100 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Relationship Between Composition, Elastic Modulus and Creep of Phenolic Plastics at Room TemperatureThe mechanical properties of thermosetting material can be modified by the type and quantity of filler or the combination of fillers. By this methode it is possible to produce a certain moulding powder for a certain application. The elastic modulus and the creep are significant values for short-time and long-time mechanical behaviour. The relationship between these both characteristic values and the compositions of moulded materials (multiphase phenolic resin systems) will be discussed.
    Notes: Die mechanischen Eigenschaften duroplastischer Teilchenverbundwerkstoffe können unter anderem durch die Wahl des Harzträgers beeinflußt und somit dem jeweiligen Anwendungsfall angepaßt werden. Für das mechanische Kurz- bzw. Langzeitverhalten sind der E-Modul und die Kriechdehnung als signifikant anzusehen, daher wird am Beispiel dieser beiden Werkstoffdaten der Zusammenhang von Formstoffzusammensetzung und mechanischen Eigenschaften aufgezeigt. Die untersuchten Phenoplast-Formstoffe bestehen aus den Hauptkomponenten Harz/Holzmehl/Gesteinsmehl.
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  • 63
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
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  • 64
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 21-30 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Investigations of Crack Initiation and Crack Propagation in Plain Carbon Steels by Means of Acoustic-EmissionCrack initiation and propagation has been studied during fatigue tests with ferritic, ferritic-pearlitic and pearlitic specimens by means of acoustic emission (A.E.) instrumentation. The ferrite and the ferrite-pearlite showed acoustic emission only in connection with fast yielding of large volumes. Early steps of crack initiation showed no detectable acoustic emission because of very small yielded volumes and small amounts of crack surface friction. Gapping of the cracks inhibited A.E. due to friction during the early steps of crack propagation. Pearlitic specimens showed strong A.E. prior to microscopic detection of cracks, ascribed to fast fracture modes.Cracks in ferritic and ferritic-pearlitic CT-specimens are only detectable by crack surface friction. The increase of yielded volume with the propagating crack is too small to be distinguished from friction noise. Pearlitic specimens showed strong burst-signal activity ascribed to cleavage fracture and fast fracture modes.Great differences in A.E. of specimens with the same microstructure are in most cases the result of differing crack surface topography and therefore very differing friction areas. Friction noise depends clearly upon loading conditions and crack surface geometry.
    Notes: An drei unlegierten Kohlenstoffstählen mit ferritischer, ferritischperlitischer und rein perlitischer Gefügestruktur wurden Untersuchungen über den Rißbeginn und den Rißfortschritt bei schwingender Beanspruchung mit Hilfe von Schallemissionsmessungen durchgeführt.Bei den Untersuchungen des Rißbeginnes konnten in den ferritischen und den ferritisch-perlitischen Werkstoffen nur rasch ablaufende Verformungsvorgänge mit ausreichendem Verformungsvolumen über die Schallemission registriert werden. Durch die örtlich begrenzten plastischen Verformungen und die geringen Flächenanteile der Rißuferreibung waren die Rißkeimbildungen nicht erfaßbar. Die ersten Stadien der Rißausbreitung ergaben ebenfalls, aufgrund des Klaffens der gebildeten Risse, keine registrierbare Schallemission durch Reibung. Bei perlitischen Werkstoffen kam es vor Erkennung eines mikroskopischen Risses zu starker Schallemission, die offensichtlich mit energiereichen Ereignissen, wie rasch ablaufenden Bruchmoden, im Zusammenhang stehen.Ein Riß ist bei Schwingungsbeanspruchung in ferritischen und ferritisch-perlitischen CT-Proben bei ausreichender Größe der Rißflächen nur über Reibung feststellbar. Der eigentliche Rißfortschritt konnte durch die geringe Volumenzunahme der plastischen Zone pro Lastwechsel nicht registriert werden. Bei perlitischen Proben trat vor allem bei grob lamellarer Ausbildung des Zementits eine starke Schallemission meist in Form von Burstsignalen auf, die vorwiegend auf die Bildung von Bruchmoden hoher Energie, wie z. B. Spaltbruch, zurückzuführen sein dürften.Die vielfach sehr starken Unterschiede der Schallemission beim Rißfortschritt in Proben gleicher Gefügeausbildung sind überwiegend der verschieden großen Rißflächenreibung durch die oft sehr unterschiedliche Topographie der Rißbruchflächen zuzuschreiben. Bei Änderung der Mittellast oder der Lastamplitude ist eine deutliche Abhängigkeit des Reibungsgeräusches aus den Rißflächen von den Rißöffnungsverhältnissen hinter der Rißfront festzustellen. Nach einzelnen Überlasten während des Rißfortschrittes kann die Schallemission in gleicher Weise mit Veränderungen der Reibungsverhältnisse hinter der Rißspitze interpretiert werden.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 60-67 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Applicability of the Potential Drop Technique for Crack Growth InvestigationsA potential drop method, based on the compensation concept is described; technical parameters and capability are discussed.Selected examples with metallic alloys for high temperature and heat resistant application demonstrate the applicability of the method for fatigue and creep crack growth investigations in the temperature range up to 1173 K and 1223 K, respectively. At room temperature and at 1173 K the results of the potential drop method are verified by optical means.
    Notes: Es wird eine Potentialsondenmethode nach dem Kompensationsprinzip vorgestellt; ihre technischen Merkmale sowie ihr Leistungsvermögen werden diskutiert.Anhand ausgesuchter Beispiele an metallischen Legierungen für den warmfesten und hitzebeständigen Anwendungsbereich wird ihr Einsatz in Versuchen zum Ermüdungs- bzw. 1223 K demonstriert. Bei Raumtemperatur sowie 1173 K wurden die Meßergebnisse durch Vergleichsmessungen mit optischen Mitteln verifiziert.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 73-76 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Hardening Behaviour of Steels by Cold WorkingContrary to common opinion work hardening increases with higher initial hardness (strength) of steel. This is proved by analysing stressstrain curves of tensile tests at overeleastic load carried out with normalized, hardened and tempered steel. Test results taken from literature are supported by own experiments. Practical application of this fact is discussed very shortly.
    Notes: Bei Stählen steigt im Gegensatz zur herrschenden Meinung die Kaltverfestigung (Aufhärtung) mit steigender Ausgangshärte oder -festigkeit an. Dies wird nachgewiesen an Ergebnissen aus Zugversuchen mit normalisierten und vergüteten Stählen. Ergebnisse der Literatur werden durch eigene Versuche ergänzt. Die praktische Nutzanwendung dieses Tatbestandes wird knapp andiskutiert.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A18 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 101-110 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Acoustic Emission Monitoring of Polymeric Composite Materials. Part II: Experimental resultsThe technique of acoustic emission monitoring of polymeric composite materials is described. It is a high sensitive, quasi-nondestructive testing method that indicates the origin and the behaviour of flaws in such materials, when submitted to different load histories. In the usage of sophisticated signal-analysis-methods it is possible to distinguish between different types of failure mechanisms, such as fiber fracture, delamination or fiber pull-out. Imperfections can be detected while monitoring complex composite structures by acoustic emission measurements.
    Notes: Das quasi-zerstörungsfreie Werkstoffprüfverfahren der Schallemissionsmessung und dessen Anwendung bei polymeren Verbundwerkstoffen wird beschrieben. Dieses Verfahren ermöglicht es, das Entstehen und das Verhalten von Werkstoffdefekten bei unterschiedlichen Lasteinwirkungen anzuzeigen. Mittels signalbewertender Analysenmethoden können die in Verbundwerkstoffen ablaufenden, unterschiedlichen Versagensmechanismen differenziert werden.Bei Bauteiluntersuchungen erweist sich das Schallemissionsmeßverfahren als außerordentlich sensitiv, um bauteilgefährdende Defekte und Werkstoffehler anzuzeigen.
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    Materialwissenschaft und Werkstofftechnik 11 (1980) 
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    Keywords: Chemistry ; Polymer and Materials Science
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    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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    Materialwissenschaft und Werkstofftechnik 11 (1980) 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 213-216 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Measurement of Residual Stress Reduction by Analysis of the Barkhausen-EffectResidual stresses and their variations under fatigue conditions have been measured by analysis of the Barkhausen-Effect.The stresses are proportional to the magnetic parameter M in a definite area.The investigations have been made on a high-strength fine-grained steel. under fatigue condition the relief of residual stresses is finished after a few stress cycles.By superposition of residual and load stresses the longitudinal stresses accept in consequence of the lateral contraction, whereas the transverse stresses are growing up in reason of their orientation to the direction of load stress.A change of the residual stress distribution could not be established.
    Notes: Eigenspannungen und ihre Veränderungen unter Ermüdungsbeanspruchung wurden durch Analyse des Barkhausen-Rauschens ermittelt. Die Spannungen sind in einem begrenzten Bereich dem magnetischen Parameter M proportional.Die Untersuchungen wurden an einem hochfesten Feinkornbaustahl durchgeführt. Bei Ermüdungsbeanspruchung ist der Eigenspannungsabbau nach wenigen Lastspielen beendet.Durch die Überlagerung von Eigen- und Lastspannungen nehmen die Längsspannungen infolge der Querkontraktion weiter ab, während die Querspannungen, da sie in Richtung der Belastung liegen, erhöht werden.Eine Veränderung der Eigenspannungsverteilung konnte nicht festgestellt werden.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A47 
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    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A52 
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    Keywords: Chemistry ; Polymer and Materials Science
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    Materialwissenschaft und Werkstofftechnik 11 (1980) 
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    Keywords: Chemistry ; Polymer and Materials Science
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  • 76
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 281-287 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Improvements in lead alloys for chemical plants, III: Mechanical propertiesThe hardness of copper-alloyed rolled lead for chemical plants is increased by further alloying additions. The hardness of the finegrained lead alloy PbCu0.04Sn0.05Pd0.03Se0.02, which is optimum as regards processability, fine-grained structure, structural stability, and corrosion resistance, lies between that of copper lead DIN 1719 and antimonial lead containing 4% Sb. The yield point (0.2% yield strength) and tensile strength of the tested rolled lead materials increase within a certain range in a linear proportion to the hardness. This also applies to the fatigue strength. The creep strength (1% time yield limit and long-time rupture strength) likewise increases with growing hardness; this dependency diminishes, however, with rising temperature and becomes insignificant at 110°C. The improvements in mechanical properties of copper-alloyed lead to be achieved by small additions of silver (up to 0.01%) are thoroughly discussed.
    Notes: Die Härte von kupferlegiertem Walzblei für den Chemie-Apparatebau wird durch weitere Legierungszusätze erhöht. Der im Hinblick auf Verarbeitbarkeit, Feinkörnigkeit, Gefügestabilität und Korrosionsbeständigkeit optimale Blei-Feinkornwerkstoff PbCu0,042Sn0,05Pd0,03Se0,02 liegt in seiner Härte zwischen derjenigen von Kupferfeinblei DIN 1719 und Hartblei mit 4% Sb. Streckgrenze (0,2%-Dehngrenze) und Zugfestigkeit der untersuchten Walzblei-Werkstoffe nehmen innerhalb einer gewissen Streubreite linear mit der Härte zu. Das gilt auch für die Wechselfestigkeit. Die Kriechfestigkeit (1% Zeitdehngrenze und Zeitstandfestigkeit) nimmt gleichfalls mit der Härte zu, wobei sich diese Abhängigkeit aber mit zunehmender Prüftemperatur abschwächt und bei 110deg;C nur noch gering ist. Die durch geringe Zusätze von Silber (bis 0,01%) erzielbaren Verbesserungen der mechanischen Eigenschaften von kupferlegiertem Blei werden ausführlich diskutiert.
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    Keywords: Chemistry ; Polymer and Materials Science
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A70 
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    Keywords: Chemistry ; Polymer and Materials Science
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    Description / Table of Contents: Influence of Levelling Processes on the Mechanical Behaviour of Spring AlloysLevelling processes - that means straightening of wire or level rolling of strip - have an impairing effect on the Rp0,2 and Rp0,1 proof strength of cold worked spring alloys and on the hysteresis behaviour of flat springs respectively. SEM and TEM investigations indicate that recovery is initiated by levelling processes and is intensified by a subsequent age hardening treatment. This may lead to a modification of age hardening behaviour and effectivity for those alloys which show different age hardening mechanisms in the cold worked and recovered state respectively.The detrimental influence of level rolling on the hysteresis behaviour is found to be due to an increased subgrain size after age hardening treatment.The results show that improvement of geometry by levelling processes is only possible at the cost of decreased spring properties.
    Notes: Das Richten kaltverformter Federlegierungen in Draht- und Bandform führt zu einer Beeinträchtigung der makroskopischen Dehngrenzen dieser Werkstoffe bzw. des Hystereseverhaltens von Blattfedern. Durch Untersuchungen im REM und TEM wird nachgewiesen, daß beim Richten eine Erholung ausgelöst und während einer anschließenden Aushärtungsbehandlung verstärkt wird. Bei Legierungen mit unterschiedlichem Aushärtungsmechanismus in kaltverformtem und erholtem Zustand kann daraus eine Änderung des Aushärtverhaltens und der Aushärteffektivität resultieren.Als Ursache eines negativen Einflusses des Richtens auf das Hystereseverhalten wird eine Zunahme der Subkorngröße nach Aushärtung gerichteter Proben festgestellt.Die Ergebnisse zeigen, daß mit einer Verbesserung der Geometrie durch Richten eine Verschlechterung der Federeigenschaften in Kauf genommen werden muß.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A78 
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    Keywords: Chemistry ; Polymer and Materials Science
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A68 
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    Keywords: Chemistry ; Polymer and Materials Science
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 312-318 
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    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Influence of Carbon Content on the Fatigue Strength of Hardened and Tempered SteelsIn hardened and tempered condition the same tensile strength can be attained by steels with different carbon contents through suitable tempering temperature. The aim of this study was to find out, whether steels with different carbon contents, having similar tensile strength, produce different fatigue limits. A new methods of evaluation through graphical description of multiple regression analysis has been used.The results of this investigation show, that, within the usual range of tensile strength, the carbon content of hardened and tempered steels is immaterial for the fatigue strength. A higher carbon content brings only then advantages, if the reduction of area is not affected by it adversely. Particularly for higher strengthes (Rm 〉 1500 N/mm2) higher carbon content is advantageous, because for steels with higher carbon a higher tempering temperature is permissible, which leads to higher ductility.
    Notes: Im vergüteten Zustand ist es im üblichen Festigkeitsbereich für die Dauerfestigkeit ohne Bedeutung, mit welchem Kohlenstoffgehalt die Zugfestigkeit eingestellt wird. Ein höherer Kohlenstoffgehalt bringt dann Vorteile, wenn die Brucheinschnürung durch den höheren Kohlenstoffgehalt nicht herabgesetzt wird. Das kann sich besonders bei höheren Festigkeiten (Rm 〉 1500 N/mm2) günstig auswirken, da dann der Stahl mit dem höheren Kohlenstoffgehalt eine höhere Anlaßtemperatur erlaubt und damit zu einer höheren Duktilität (Brucheinschnürung Z) führt.Bei Stählen mit niedrigem Kohlenstoffgehalt (C 〈 0,3%) wird die höchste Schwingfestigkeit im gehärteten, nicht angelassenen Zustand erzielt, bei Stählen mit höherem Kohlenstoffgehalt nach Anlassen zwischen 200 und 450 °C.Die maximal erreichbare Biegewechselfestigkeit liegt bei 850 ± 100 N/mm2, sie wird von allen Vergütungsstählen mit C 〉 0,3% erreicht.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A71 
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    Keywords: Chemistry ; Polymer and Materials Science
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 440-446 
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    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Description / Table of Contents: Wear of Processing Equipment and Moulds by Filled and Reinforced PlasticsThe introduction of filled and reinforced plastics into the market increased the problem of wear during processing. It is estimated that in Germany wear based losses are up to 500 Millions DM per annum. Special test methods have been developed for systematic analysis of wear phaenomena. A considerable progress has been achieved in solving these problems in close contact to the concerning industry.
    Notes: Mit der Einführung gefüllter und verstärkter Kunststoffe haben die Verschleißprobleme bei der Verarbeitung zunehmend an Bedeutung gewonnen. Die durch Verschleiß verursachten Verluste in der Kunststoffindustrie werden in der Bundesrepublik Deutschland derzeit auf 500 Mill. DM pro Jahr geschätzt. Zur systematischen Untersuchung und zur Analyse der Verschleißerscheinungen wurden Modellprüfverfahren entwickelt. In enger Zusammenarbeit mit der Industrie konnten bereits beachtliche Erfolge bei der Minimierung der Verschleißschäden erzielt werden.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 451-451 
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    Description / Table of Contents: Meßanordnung zur Aufstellung von Kontaktkorrosions-Tabellen - Werkstoffkombinationen in Meer- und BrackwasserDer Einsatz von Konstruktionen und Apparaten in Mischbauweise wirft die oft schwierige Frage auf, welche Werkstoffe sich ohne Gefahr einer Kontaktkorrosion miteinander kombinieren lassen.Mit der in Zukunft zu erwartenden ansteigenden Verwendung von Meer- und Brackwasser als Kühlmittel für industrielle Zwecke ist die Kenntnis über das korrosionschemische Verhalten von Werkstoffkombinationen gerade in diesen Medien von Interesse.Es wurde eine automatisch arbeitende Meßeinrichtung entwickelt, welche die Erfassung der freien Korrosionspotentiale der einzelnen Werkstoffe, des Mischpotentials der kurzgeschlossenen Werkstoffkombinationen und des fließenden Elementstromes in einer größeren Zahl von Meßzellen gestattet.Die gewonnenen Ergebnisse, insbesondere die Elementstromdichte, erlauben gegenüber den bisher vielfach angewendeten praktischen Spannungsreihen eine wesentlich verbesserte Aussage über die Größe der zu erwartenden Kontaktkorrosionsionsrate.Die mit dieser Meßeinrichtung gewonnenen Ergebnisse werden in einer neuen Art dargestellt und in sogenannten Kontaktkorrosions-Tabellen für eine Vielzahl von Werkstoffkombinationen zusammengefaßt.
    Notes: For better estimates of the galvanic corrosion hazard a method is described which allows measurement and recording of the individual potentials, the mixed corrosion potential and the element current of conductively jointed metal couples in electrolytes.The data acquired from numerous couples of materials can be compiled into galvanic corrosion tables for different aggressive media which represent the galvanic corrosion behaviour in a considerably improved, more quantitative form than the previously used potentials listed in the “practical” electromotive series.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 417-422 
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    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Application of Fracture Mechanics for the Improvement of the Life Time of Forming DiesAn investigation was undertaken to determine the life times of dies when these life times are determined by crack propagation from such stress raisers as notches. Notched DCB specimens were used to investigate the processes of crack initiation and propagation in the high temperature steel X 40 CrMo V 51 at 500°C. The results showed that the life times depend both on the heat treatment of the material and also on the length of hold time at temperature. Hold times during the forming process should be minimized in order to avoid fast creep crack propagation.
    Notes: Die Lebensdauer von Werkzeugen in der Umformtechnik wird in vielen Fällen durch die Entstehung von Rissen begrenzt, die in Gebieten mit hohen Spannungen wie Kerben auftreten. Zur Bestimmung der Lebensdauer wurden an gekerbten Proben aus dem Warmarbeitsstahl X 40CrMo V 51 bei 500°C Rißeinleitung und Rißfortschritt untersucht. Es zeigt sich, daß die Lebensdauer einerseits von der Wärmebehandlung des Gesenkwerkstoffes, andererseits von der Haltezeit beim Umformen abhängt. Die Haltezeiten sollten so kurz wie möglich sein, um schnelles Kriechrißwachstum zu vermeiden.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 446-450 
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    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Relationship between Piston Ring Fracture and Piston Ring Flank Wear AccelerationIn wear measuring experiments on diesel engines a relationship between the fracture of the first piston ring and the wear acceleration of the ring flank of the same piston ring was found.A special series of the experiments was designed to clarify this connexion. The results from both the initial experiments and the extra series of experiments are described.
    Notes: Es wurde eine Korrelation zwischen dem Bruch des 1. Kompressionsringes eines Dieselmotors und der Ringflanken-Verschleißbeschleunigung des Kolbenringes gefunden. Es werden die Versuchsergebnisse geschildert, die die ersten Hinweise lieferten sowie die Ergebnisse einer Versuchsserie zur Absicherung der gefundenen Korrelation.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A95 
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A2 
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    Keywords: Chemistry ; Polymer and Materials Science
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 14-20 
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    Keywords: Chemistry ; Polymer and Materials Science
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    Description / Table of Contents: Methodische Schadenanalyse und programmierter Untersuchungsablauf zur Erhöhung der Sicherheit von Bauteilen und AnlagenZur Steigerung der Sicherheit von Maschinen und Anlagen muß eine systematische Schadenanalyse in die technische Entwicklung mit einbezogen werden. Es wird die Methodik einer Schadenanalyse beschrieben, die auf der Grundlage der in den letzten Jahren entwickelten Konstruktionsmethodik beruht. Zur Durchführung der methodischen Schadenanalyse sind Betrachtungen über Beanspruchung und Beanspruchungsreaktionen vorzunehmen. Schadenmerkmale und Schadenmechanismen werden einheitlich gekennzeichnet und in eine normierte Zuordnung gebracht. Mit diesen Voraussetzungen ist es möglich, die Arbeitsweise der Schadenuntersuchung zu programmieren. Schließlich ermöglicht die beschriebene Arbeitsmethodik eine einheitliche und vergleichbare Speicherung und Auswertung von Schadendaten.
    Notes: To increase the safety of machines and plants, a systematic failure analysis must be integrated into the technical development. The methodic of a failure analysis is described, which is based on the construction methodology, which has been developed during the past few years. To effect a methodical failure analysis, considerations on stresses and stress reactions must be carried out. Failure characteristics and failure mechanisms are identified uniformly and brought into a standardized combination. Based on these conditions it is possible to programme the working method of the failure analysis. Finally the working method described permits a standardized and comparable storage and evaluation of failure data.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A10 
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    Description / Table of Contents: Acoustic Emission Monitoring of Polymeric Composite Materials. Part I: The Technique of Acoustic Emission MonitoringThe importance of nondestructive testing methods increases in material and structure production control techniques as well as in the practical, calculated usage of faulty structures.The technique of acoustic emission is a useful aid in monitoring complex structures in real time mode. In Part I the fundamental measuring technique of this testing method is discussed.
    Notes: Im Rahmen der Qualitätssicherung von Werkstoffen und Bauteilen aber auch des kalkulierten praktischen Einsatzes defekthafter Strukturen in der Praxis ist den zerstörungsfreien Werkstoffprüfverfahren eine bedeutende Rolle beizumessen.Als Echtzeitprüfung, bei der das gesamte Bauteilvolumen erfaßt wird, findet das Schallemissionsmeßverfahren immer mehr Anwender. In diesem Beitrag werden die prinzipiellen, meßtechnischen Grundlagen dieses Verfahrens diskutiert.
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    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 56-59 
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    Keywords: Chemistry ; Polymer and Materials Science
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    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Determining the Distribution of Residual Stresses in Cylindrical Solid Bodies by Employing Different Computation MethodsThere are two methods for the computation of residual stresses in cylindrical bodies. The methods in question are by G. Sachs and E. Krägeloh. The residual stresses are computed out off the determined stresses. The basis of the two methods are two different hypothesises with different assumed tension gradients and elongation gradients across the sample cross-section. The methods differentiated for homogeneous and inhomogeneous materials meet with their differential equation the balance conditions.The different methods employed show considerable differences in regard to circumferential tensions. This differences result particularly at the cylinder wall surface (outside). The tension differences grow with increasing cylinder wall thickness. The longitudinal tensions and radial tensions computed by the methods of G. Sachs and E. Krägeloh are nearly identical.It is much more important to know the tendency of the residual stress distribution in a given solid body than to know the absolute value of the residual tension conditions.It is to recommend, to employ the method developed by G. Sachs, because the computing expenditure is much less than the one necessary for the method of E. Krägeloh.
    Notes: Die Berechnungen von Eigenspannungen aus den bei der Formänderungsanalyse gemessenen Dehnungsverläufen an zylindrischen Körpern lassen sich für homogene Werkstoffe nach zwei bekannten Berechnungsverfahren durchführen. Diesen beiden Verfahren liegen grundsätzlich unterschiedliche Hypothesen der angenommenen Spannungs- bzw. Dehnungsverläufe über den Probenquerschnitten zugrunde. Die Verfahren, abgeleitet für homogene und inhomogene Werkstoffe, erfüllen mit ihren jeweiligen Differentialgleichungen die Gleichgewichtsbedingungen.Bei den Umfangsspannungen lassen sich erhebliche Differenzen in den errechneten Spannungswerten bei Anwendung der beiden Verfahren an homogenen Werkstoffen nachweisen. Beim Abdrehversuch ergeben sich diese Abweichungen insbesondere am Zylindermantel, wobei sich die Spannungsunterschiede mit zunehmender Wanddicke vergrößern. Dagegen weichen die nach beiden Verfahren bestimmten längs- und Radialspannungen nur unwesentlich voneinander.Viel wichtiger als die Ermittlung der absoluten Eigenspannungszustände in einem Körper ist vielmehr die Kenntnis von der Tendenz des Eigenspannungsverlaufs. Nicht zuletzt auch wegen des geringeren rechnerischen Aufwandes ist die Anwendung des Sachschen Berechnungsverfahrens bei der Eigenspannungsanalyse an homogenen Werkstoffen empfehlenswert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 11 (1980), S. A15 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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