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  • 1
    Electronic Resource
    Electronic Resource
    Effect of hydrogen bonding on the acid character of some synthetic copolymers (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 2377-2381 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A copolymer of p-hydroxybenzoic acid, formaldehyde, and p-bromoaniline was prepared in the presence of acid catalyst, and five fractions have been separated from it. Br content of each of the fractions was determined by chemical analysis, and on the basis of mole ratio of repeating units present in the copolymer chain, the total amounts of acidic and basic groups in a given weight of the copolymer were calculated. Nonaqueous titrations of all the fractions have been carried out in acidic and basic medium with suitable titrants. An excellent correlation was observed between the calculated and observed values of functional groups. The features of the titration curves were interpreted in terms of intramolecular hydrogen bonding and homoconjugation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160924
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  • 2
    Electronic Resource
    Electronic Resource
    Molecular weight of polystyrene polymer obtained in the emulsion polymerization at low monomer concentration and the harkins-smith-ewart-gardon (HSEG) theory (1979)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 2193-2207 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The shape of the yield-time curves in the emulsion polymerization of styrene is a function of the recipe composition. Three types of yield-time curve were observed: (1) sigmoidal, (2) linear from the onset of polymerization, and (3) concave to the time axis; that is, the rate falls off continuously from the outset of polymerization. The viscosity-average molecular weights (M̄v) of the polymers in a given run are approximately parallel to the average rate of polymerization [i.e.,(yield of polymer at time t)/(time t)]. The Harkin-Smith-Ewart-Gardon (HSEG) theory provides a qualitative description of the emulsion polymerization of styrene at low monomer concentration if the yield-time curve is sigmoidal. From Gardon's equations it is found that the average number of radicals per particle (Q) varies from 0.5 to 2.0, depending on the composition of the recipe. The (M̄v)expt/(M̄v)calc ratio lies between 1 and 2. The termination/propagation rate constant (kt/kp) ratio is a function of the composition of the recipe at a given temperature of polymerization and varies from 0.78 to 11.5 when it is estimated from the experimental data. The theoretical value, however, is 117.0. It has been shown that for a polydisperse system with particles of radius (r) between 10 and 1000 Å the maximum number of latex particles (N1)/ml of the aqueous phase would be 1019-1013; that is, if 10 ≤ r ≤ 1000 Å, then 5.97 × 1019 ≥ N1 ≥ 5.97 × 1013/ml.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1979.170170727
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  • 3
    Electronic Resource
    Electronic Resource
    Kinetics and mechanism of the emulsion polymerization of styrene in the aqueous media at 50°C and at low monomer concentration initiated by persulfate. I. Initiation (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 1517-1525 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mechanism of the water-soluble persulfate-initiated emulsion polymerization of styrene in the aqueous media at 50°C has been investigated kinetically by the conventional dilatometric and gravimetric methods at low concentration of the monomer (5% v/v). It has been found that the initial rate of polymerization Vp is approximately proportional to initiator concentration [I] to the 0.50 power, i.e., Vp ∝ [I]0.50, and the viscosity-average molecular weight Mv is approximately inversely proportional to the 0.50 power of the initiator concentration, i.e., Mv ∝ [I]-0.50. With the progress of the reaction, the initiator exponent of the reaction rate equation decreases gradually from 0.50 to 0.25, but that of the molecular weight (1) equation remains constant up to 20% conversion and thereafter begins to decrease. Since the kinetic data at zero conversion satisfy the steady-state kinetics of the free-radical-initiated homogeneous vinyl polymerization, it is suggested that the initiation of emulsion polymerization of styrene is a two-step process. It starts in the aqueous phase by the primary free radicals from the water-soluble initiator or secondary free radicals derived from the soap molecules. The second step occurs in the monomer-leaded micelles by the water-soluble or water-insoluble macroradicals or by radicals derived from the soap molecules. The latter are likely to be produced in the aqueous phase by the oxidation of soap with S2O82-ions or SO4- radicals. It has been noted that the rate of thermal decomposition of persulfate increases by a factor of 6-8 times under different experimental conditions in the presence of soap.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160706
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  • 4
    Electronic Resource
    Electronic Resource
    Studies on ceric-thiol-initiated aqueous vinyl polymerization with particular reference to end groups in poly(methyl methacrylate) (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2585-2595 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ceric-thiol systems are good initiators for the acid aqueous polymerization of some water-soluble Vinyl monomers although not for styrene (in aqueous emulsion) and vinyl acetate. Thiols used are 2-mercaptoethanol, thioglycolic acid, 2-mercaptoethylamine hydrochloride, and L-cysteine hydrochloride. The polymerization proceeds through a radical mechanism. End-group analysis of poly(methyl methacrylate) obtained by initiation with various ceric-thiol systems has been carried out using Palit's dye testes. Hydroxyl, carboxyl, and amine end groups (to the extent of about one per polymer molecule) were incorporated in poly(methyl methacrylate)s obtained by initiation with 2-mercaptoethanol, thioglycolic acid, and 2-mercaptoethylamine hydrochloride, respectively, each in combination with Ce4+ ions; both amine and carboxyl end groups were obtained using C4+/L-cysteine hydrochloride initiator system. From the end-group results, the initiating species have been identified and the initiation mechanism prooposed. The probable termination mechanism also has been discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180817
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  • 5
    Electronic Resource
    Electronic Resource
    Analysis of some phenolic copolymer mixtures by electrometric titration techniques (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 1009-1016 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some two-, three- and four-component phenolic copolymers have been characterized, and mixed in definite stoichiometric proportions. The total amount of acidic and basic functional groups in a given weight of the copolymer mixture have been calculated from the characteristic parameters of the polymer components. Analysis of these copolymer mixtures by electrometric titration techniques revealed an excellent correlation between the calculated and observed values of functional groups.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.170230406
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  • 6
    Electronic Resource
    Electronic Resource
    Mechanistic studies on ceric-thiourea-initiated polymerization of methyl methacrylate in acid-aqueous media from end group analysisPresented at the Symposium on Polymer Chemistry sponsored by the University Grants Commission of India. (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 311-319 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mechanism of the redox polymerization of methyl methacrylate in acid-aqueous medium was studied for ceric-thiourea initiator system by analysis of polymer end groups using the dye partition method. Polymerization at room temperature and at pH 2.30 with this initiator system incorporates mostly amino end groups in the polymers to the extent of 1.18-1.31 and a small amount of hydroxyl end group not exceeding 0.08 per polymer molecule. Under the same pH condition, a higher polymerization temperature increases the amine end group content to 2.17-2.30 and hydroxyl end group content to 0.14-0.18 per polymer molecule. A lower polymerization temperature (5°C), or a lower pH (ca. 1) of the reaction medium, produces polymers with exclusively amine end groups, hydroxyl end groups being totally absent. At pHs greater than 3, amine end group incorporation decreases significantly, with simultaneous increase in hydroxyl incorporation. On the basis of end group results the initiating radical has been identified and the mechanism of initiation has been suggested. The possible mode of termination has also been discussed.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180129
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  • 7
    Electronic Resource
    Electronic Resource
    Effects of structure and composition on the titration curves of some synthetic copolymers in nonaqueous media (1973)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 11 (1973), S. 1261-1270 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: p-Aminobenzoic acid, p-hydroxybenzoic acid, and formaldehyde were condensed in various molar proportions in the presence of acid catalyst to obtain copolymers of various compositions. Conductometric and potentiometric titrations were carried out on seven copolymers having different feed compositions in nonaqueous solvents with acid as well as base. The titration curves indicated a large number of additional breaks inflections before the complete neutralization of COOH, OH, or NH2 groups. These observations have been interpreted in terms of degree of polymerization, composition, and structure of the copolymers.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1973.170110613
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  • 8
    Electronic Resource
    Electronic Resource
    Titration curves of some structurally and molecularly uniform polynuclear phenolic compounds with additional functional groups (1974)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 12 (1974), S. 211-219 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1974.170120119
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  • 9
    Electronic Resource
    Electronic Resource
    Grafting of acrylamide onto methyl cellulose by persulfate ion (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 141-148 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Acrylamide was grafted onto methyl cellulose backbone by using potassium persulfate as initiator in aqueous solution, and variables affecting the copolymerization were studied. It was found that efficiency of grafting was maximum at an initiator concentration of 3.7 × 10-4 mole/l. Grafting was found to increase steadily with increase in monomer/polymer ratio and with temperature up to 40°C.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.170150114
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  • 10
    Electronic Resource
    Electronic Resource
    Effect of monomer functional groups on the composition of some three component random phenolic copolymers (1981)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 3005-3012 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some three-component random phenolic copolymers were prepared from three typical phenolic monomers; for example, p-chlorophenol, p-aminophenol, and p-cresol. Several samples of the copolymer were prepared by changing the feed composition and the composition of the copolymers was established by estimating —NH2 and —OH groups by electrometric titration techniques in nonaqueous media. Halogen was estimated by Volhard's method. The average degree of polymerization (DP) of the copolymers was calculated from the features of the electrometric titration curves, and the effects of monomer functional groups on the composition of the copolymers were interpreted in terms of the electron-donating and electron-attracting nature of the substituents present in the monomers.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1981.170191132
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