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  • Polymer and Materials Science  (15)
  • poly(benzobisthiazole)  (2)
  • Alloplasmic  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Generation and characterisation of monosomic chromosome addition lines of Brassica campestris - B. oxyrrhina (1998)
    Springer
    Theoretical and applied genetics 97 (1998), S. 976-981 
    Details
    ISSN: 1432-2242
    Keywords: Key words Chromosome addition line ; Synteny group ; Brassica campestris ; Brassica oxyrrhina ; Monosomic ; Alloplasmic ; RAPD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Monosomic chromosome addition lines of Brassica oxyrrhina in the background of alloplasmic B. campestris carrying B. oxyrrhina cytoplasm were generated and characterised through morphology, cytology and molecular (RAPD) analysis. Four successive backcrosses of the synthetic alloploid B. oxycamp with B. campestris yielded 24 monosomic addition plants that were grouped into seven different synteny groups based on morphological similarity and RAPD patterns. Each synteny group exhibited morphological features diagnostic for the presence of individual B. oxyrrhina chromosomes including some novel phenotypes. Meiotic studies of the addition lines revealed the homoeology of four B. oxyrrhina chromosomes (synteny groups 1, 3, 5 and 6 ) with B. campestris chromosomes as indicated by trivalent associations, with the highest homoeology (44.23%) in synteny group 1 and the lowest (6.1%) in synteny group 3. Seed fertility of the addition lines ranged from 94.85% (synteny group 1) to 56.98% (synteny group 5). All of the addition lines were male-sterile except synteny group 6 which had 12–16% stainable pollen. Ovule transmission of the B. oxyrrhina chromosomes added to the progenies of addition lines ranged from 23.52% (synteny group 6) to 14% (synteny group 7). RAPD analysis confirmed the validity of synteny grouping based on morphological observations. Approximately 45% of the primers studied were informative, giving B. oxyrrhina-specific RAPD bands unique for each synteny group, except group 6.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220050979
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  • 2
    Electronic Resource
    Electronic Resource
    Mechanochemical process in cotton cellulose fiberCorrected proofs received October 22, 1982 (1983)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 28 (1983), S. 1-10 
    Details
    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: Mechanical processing of cotton cellulose by means of a fiber cutter resulted in the disaggregation and defiberation of fiber bundles, shortening of fiber length, and loss of degree of polymerization. It is evident that the mechanical energy supplied by shear forces is sufficient to cause homolytic scission of cellulose main chains. Mechanoradicals formed in the interim were verified by ESR studies. The crystallinity of cellulose was not influenced by mechanical treatments, but accessibility of the polymer was substantially increased due to the creation of new surfaces. The mechanically treated fiber inclined to proceeded oxidative chain reaction during aging. Regardless of their treatment conditions, cellulose fiber reached its limiting lower molecular weight after 100 days of aging.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1983.070280101
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  • 3
    Electronic Resource
    Electronic Resource
    New aromatic benzazole polymers II: Synthesis and conductivity of benzobisthiazole-co-polymers incorporated with 4-N,N-dimethylaminotriphenylamine groups (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 713-724 
    Details
    ISSN: 0887-624X
    Keywords: poly(benzobisthiazole) ; copolymers ; 4-N,N-dimethylaminotriphenylamine ; conducting polymers ; iodine doping ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New aromatic benzobisthiazole copolymers containing 10-70 mol % of 4-N,N-dimethylamino-triphenylamine functionality were prepared from the respective dinitrile or dicarboxylic acid monomers, terephthalic acid, and 2,5-diamino-1,4-benzene-dithiol dihydrochloride in polyphosphoric acid. At the first approximation, the copolymers containing 10 mol % or less of the triarylamino moieties in the polymer chains still preserve the capability to form anisotropic (nematic) solutions at 10 wt % polymer concentration. This is an important requirement for processing the copolymers into fibers and films with good to excellent mechanical properties. Films with good mechanical integrity were cast from the dilute methanesulfonic acid solutions of the copolymers under reduced pressure. They showed electrical conductivity values of the order of 10-11-10-10 S/cm in pristine state, with four to seven orders of magnitude increase upon exposure to mild oxidizing agents such as iodine vapor. On the contrary, the parent polymer, poly(p-phenylene benzobisthiazole) is an insulator with conductivity of less than 10-12 S/cm, and its conductivity does not improve at all with exposure to iodine vapor. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 713-724, 1998
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New aromatic benzazole polymers. I. Benzobisthiazole and benzobisoxazole polymers with main-chain triarylamino units (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 1909-1924 
    Details
    ISSN: 0887-624X
    Keywords: poly(benzobisthiazole) ; poly(benzobisoxazole) ; triphenylamine derivatives ; conducting polymers ; iodine doping ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermally stable, nonrigid-rod poly(benzobisthiazoles), (R)TPA-PBZT, where R = H, Me, NMe2, and OH, and poly(benzobisoxazoles), (R)TPA-PBO, where R = Me, NMe2 containing electron-rich triarylamine groups with various para-substituents (Rs) on the pendent phenyl ring, were synthesized from either 2,5-diamino-1,4-benzenedithiol dihydrochloride or 2,4-diamino-1,5-benzenediol dihydrochloride and the respective triarylamine-based dinitrile or diacid monomer in polyphosphoric acid. Whereas (R)TPA-PBZT polymers were obtained in moderate molecular weights, analogous (R)TPA-PBO polymers were only prepared in low molecular weights. No lyotropic behaviors, characteristic of the unmodified rigid-rod benzazole polymers, as evidenced by the absence of either stir opalescence or birefringence under crosspolarizers, were observed for these homopolymers at about 10 wt % polymer concentration. Among these polymers, only (Me)TPA-PBZT and (NMe2)TPA-PBZT formed cast films with good mechanical integrity. In their pristine state, their film conductivity values were in the range of 10-10-10-9 S/cm at room temperature. Upon exposure to iodine vapor, their conductivities were increased to the maximal values of 5.0 × 10-5 S/cm ((Me)TPA-PBZT) and 4.1 × 10-4 S/cm ((NMe2)TPA-PBZT). © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1909-1924, 1997
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Polymeric isocyanates by nontoxic routes. II. Nucleophilic displacement reaction on chloromethyl pendant groups by alkali cyanates (1992)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 1911-1916 
    Details
    ISSN: 0887-624X
    Keywords: polymeric isocyanates ; polymeric crosslinkers ; nontoxic routes ; chloromethyl polystyrene ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The environmental regulations regarding the solvent emissions have given impetus to the formulation of powder coatings and high solids coatings which require oligomeric or polymeric crosslinkers of desired functionality. We are exploring nontoxic routes for the preparation of polymeric isocyanates and isocyanate precursors. In this article, we report nucleophilic displacement of polymer-bound alkyl halides by cyanate ion as a novel route to polymeric isocyanate crosslinkers with no intermediacy of either phosgene or low molecular weight isocyanates. The effects of solvent and phase-transfer catalyst on the selectivity of the reaction are discussed. © 1992 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1992.080300913
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  • 6
    Electronic Resource
    Electronic Resource
    Glass fiber reinforced polypropylene/EPDM blends. II. Mechanical properties and morphology (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 43 (1991), S. 451-462 
    Details
    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: Tensile and impact properties of the ternary system polypropylene (PP)/ethylene propylene diene elastomer (EPDM)/glass fiber (GF) and the corresponding binary systems PP/EPDM blend and PP/GF composite are studied. Results are presented and analyzed as functions of compositional variables, viz., (i) matrix PP/EPDM blending ratio at constant GF loadings and (ii) GF loading at constant matrix blending ratios for the ternary system and (iii) EPDM content for PP/EPDM binary system and (iv) GF content for the binary system PP/GF, respectively. The role of individual components EPDM and GF in these mechanical properties is discussed and their combined effects are inspected at certain composition ranges. Theoretical analysis of tensile data is presented which reveals the effect of EPDM on the reinforcing effect of GF. Unlike the conventional role of an elastomer, increase of EPDM content in the presence of GF increases the modulus of the ternary system. Impact strength of the ternary system increases with increasing GF content both in the presence and absence of EPDM, showing a distinct minimum at matrix blending ratio PP/EPDM 90/10. Scanning electron micrographs of impact-fractured surfaces are presented to illustrate the dispersion of the two phases of the polyblend matrix, fiber alignment, and the fiber interface.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070430306
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  • 7
    Electronic Resource
    Electronic Resource
    Melt-rheological properties of PP/EVA blend (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 46 (1992), S. 281-293 
    Details
    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: This paper describes a study of melt-rheological properties of the binary blend of isotactic polypropylene (PP) and ethylene-vinyl acetate copolymer (EVA) at varying blending ratios (from 0 to 40 wt % EVA content) and using three samples of EVA containing different vinyl acetate contents (VA %), viz. 9, 12, and 19%. Measurements made on a capillary rheometer at three different temperatures (210, 220, and 230°C) in a shear stress range of 104-106 Pa (shear rate 101-104 s-1) are presented and discussed for the effects of blend composition and shear stress on the flow curves, melt viscosity and melt elasticity. Morphology of the blend studied through scanning electron microscopy revealed distinct differences in size and number density of dispersed EVA droplets, which are discussed in terms of the variation of average size and number density of the dispersed EVA droplets as a function of blend composition and shear stress. Melt-rheological properties and morphology of dispersion are correlated and found quite consistent.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1992.070460209
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  • 8
    Electronic Resource
    Electronic Resource
    Melt rheology and morphology of PP/SEBS/PC ternary blend (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 47 (1993), S. 167-184 
    Details
    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: Melt rheological properties of the ternary blend of isotactic polypropylene (PP), styreneethylene-butylene-styrene terpolymer (SEBS), and polycarbonate (PC), PP/SEBS/PC, are studied in a wide range of composition, such that PP is the matrix and SEBS and PC are the minor components, with the proportion of one varying from 0 to 30% at various fixed compositions of the other. The respective binary blends, PP/SEBS and PP/PC, studied as the reference systems for interpretation of results on the ternary blends yielded interesting new information about the morphology development and its correlation with melt rheological properties of these binary blends. The studies include the measurement of melt rheological properties on a capillary rheometer in the shear rate range 101-104 s-1 at a fixed temperature of 240°C. The data presented as conventional flow curves are analyzed for the effect of blend composition and shear rate on pseudoplasticity, melt viscosity, and melt elasticity, and role of each individual component is identified. Morphology of dispersed phases of these blends is studied through scanning electron microscopy of the cryogenically fractured and suitably etched surfaces. Variations of morphology with blend composition and shear rate showed interesting correlation with melt rheological properties, which are discussed in detail. An important finding of the morphological studies is that in the PP/SEBS/PC ternary blend the SEBS phase forms two types of morphologies depending on the blend composition and shear rate: (i) simple droplets and (ii) boundary layer at the surface of the PC droplets. © 1993 John Wiley & Sons, Inc.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1993.070470118
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  • 9
    Electronic Resource
    Electronic Resource
    Mechanical properties and morphology of PP/SEBS/PC blends (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 53 (1994), S. 1-17 
    Details
    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: Rubber toughening of thermoplastic polymers always decreases the tensile and flexural properties. In this article, an attempt is made to improve the tensile and flexural properties of a rubber-toughened polymer system viz., polypropylene (PP)/styrene-ethylene-butylene-styrene tri-block copolymer (SEBS) binary blend by blending a rigid polymer viz., polycarbonate (PC) with this binary system. The PP/SEBS blend with a blending ratio fixed at three levels, namely 95/5, 90/10, and 80/20, was melt mixed with 0-30 wt % PC to generate the various blend compositions studied. This choice of compositions enabled us to show how the mechanical properties varied as a function of (1) PP/SEBS ratio at a constant PC content and (2) PC content at a constant PP/SEBS ratio of the blend. Data on the corresponding binary blends, namely PP/SEBS and PP/PC, are also presented and discussed as reference systems. The data are discussed in detail for the effect of each component of the blend. As regards the morphology, some distinct changes were seen in the middle of composition ranges of the additives, i.e., around 10 to 20% PC level, and 95/5 and 90/10 PP/SEBS ratios. Variation of mechanical properties in the respective composition ranges are found consistent with the variations of blend morphology. Hence, a correlation of morphology and the properties is discussed. Furthermore, the results suggest stronger interfacial interaction between SEBS and PP than that between PC and PP. Scanning electron microscopic studies of appropriately etched impact fractured samples reveal the existence of composite droplets of SEBS and PC embedded in PP matrix, with SEBS forming the outer envelope around PC. © 1994 John Wiley & Sons, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1994.070530101
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  • 10
    Electronic Resource
    Electronic Resource
    Free radical copolymerization of poly(n-butyl methacrylate) onto polychloroprene (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 37 (1989), S. 1551-1558 
    Details
    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 n-butyl methacrylate onto polychloroprene was carried out in toluene using benzoyl peroxide as an initiator. The polychloroprene-g-poly(n-butyl methacrylate) was isolated from the copolymerization product by extracting with hexane. Infrared (IR) spectra and nuclear magnetic resonance (NMR) of graft copolymer showed the occurrence of grafting. Percentage of grafting and grafting efficiency calculated under different experimental conditions were discussed. The mechanism of grafting seems to occur by chain transfer, as evidenced by a decrease in chlorine content during the experiment.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1989.070370609
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