摘要:

Radical copolymerization of styrene (St, M1) with methyl vinylsulfoxide (MVSO, M2) has been carried out in various solvents at 80°C. Good linear correlationships were obtained by plotting the values of log r1against those ofvS-O frequencies of MVSO determined in the solvents and of ω and ETvalues of solvents used.

ISSN:0022-233X    

DOI:10.1080/00222338108056807

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The aqueous polymerization of acrylamide initiated by the redox system Ce(1V)-thioglycolic acid has been studied at 35 ± 0.2°C. The pH measurement shows that a 1:1 metal:ligand complex is formed between Ce(IV) and thioglycolic acid (TGA). The rate of polymerization is given by RP=K[M]1.08[Ce4+]0.65[TGA]°

ISSN:0022-233X    

DOI:10.1080/00222338108056808

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Vinyl polymerization of acrylonitrile initiated by the redox system Mn3+/tartaric acid was investigated in aqueous sulfuric acid in the temperature range 30–50°C, and the initial rates of polymerization, Mn3+disappearance, etc. were measured. The effects of certain water-miscible organic solvents, neutral electrolytes, dyes, and solid substances on the rate of polymerization have been investigated. A mechanism involving the formation of a complex between Mn3+and tartaric acid, whose decomposition yields the initiating free radical with the polymer chain being terminated by mutual interaction of growing radicals, has been suggested.

ISSN:0022-233X    

DOI:10.1080/00222338108056809

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A combined system of potassium permanganate and pyruvic acid was found to initiate radical polymerization of vinyl monomers, especially acrylamides. From kinetic investigations of the polymerization of methacrylamide, it was found that this initiator induced a radical polymerization which proceeded with an overall activation energy of 15.7 kcal/mol. The rate is given by

ISSN:0022-233X    

DOI:10.1080/00222338108056810

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Reactivity ratios relative to the copolymerizations of 1-vinyl naphthalene and 2-vinyl naphthalene with styrene have been determined at different specific temperatures. In the case of the system 1-vinyl naphthalene-styrene, the Arrhenius plot exhibits a curve when the temperature is above -50°C. This is explained by the depropagation contribution, The value of the enthalpy of polymerization calculated by using the Lowry relation is in satisfactory agreement with that obtained from calorimetric determinations. From activation enthalpies and entropies it appears that the selection of the two monomers by the cation is entropically controlled for 2-vinyl naphthalene and enthalpically controlled for 1-vinyl naphthalene.

ISSN:0022-233X    

DOI:10.1080/00222338108056811

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

1H-NMR spectra of copolymers of isobutylene and 1,3-butadiene, isoprene, and 2,3-dimethyl-1,3-butadiene were investigated in connection with the elucidation of the formation of soluble and insoluble copolymers. For copolymers soluble in heptane, benzene, and CCI4it was found that the incorporation of diene into the polymer chain proceeds by 1,4-addition in the case of copolymerizations conducted both in the dark and with visible light using VC14as initiator. The formation of a soluble and an insoluble copolymer is attributed to a different type of initiation, either with radical-cations of isobutylene, if soluble copolymers are formed, or with radical-cations of diene, if the arising copolymers are insoluble.

ISSN:0022-233X    

DOI:10.1080/00222338108056812

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

By the interfacial condensation of acid chlorides I, II, and III, respectively, with bifunctional phenols (IV-X), soluble or mold-able thermostable polyarylates were obtained. Similarly, copolyarylates were prepared from a mixture of the acid chlorides I + II or I + III. With bisphenol-A (VIII), soluble polymers are usually obtained. Methylene dichloride and/or carbon tetra-chloride-water systems were the best media for interfacial condensations, and the polymers formed showed the highest reduced viscosity values.

ISSN:0022-233X    

DOI:10.1080/00222338108056813

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Interfacial condensation of decamethylenediamine and acid chlorides I, II, and III yielded polyamides the thermal stability of which decreased in the order III, I, II, a finding reasserted by calculating activation energy decomposition temperatures. Irradiation of these polyamides does not appreciably affect their properties, and thus they can be considered satisfactorily γ-irradiation resistant.

ISSN:0022-233X    

DOI:10.1080/00222338108056814

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

An attempt has been made to prepare some new polyamide hydrazides of high thermal stability with different dicarboxylic acid chlorides by the solution polymerization technique. The polymerization was carried out at -20°C. Amide linkage was present in each polymer unit. Results of thermal degradation and thermogravimetric analysis indicate that these polymers melt or decompose above 350°C, and the steep weight loss of the polymer takes place in the range 360–390°C. Most of the polyhydrazides are soluble in organic solvents.

ISSN:0022-233X    

DOI:10.1080/00222338108056815

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The hydrolysis behavior of a number of polymers of bithionol [2,2′-thiobis(4,6-dichlorphenol)] was investigated. The hydrolysis of polyesters of bithionol with aliphatic or aromatic dicarboxylic acids or phosphorus acids as well as polycarbonates and alternating copolycarbonates and polyurethanes or co(po1y-carbonates/polyurethanes) depends primarily on the water solubility of the polymer or at least on its degree of swelling. In the most favorable case of the alternating bithionol/PEG 4000 co-polycarbonate the hydrolysis rate of the polymer at 37°C was 1.62 L/mol/min at pH 10, 0.63 L/mol/min at pH 4 and 0.17 L/mol/min at pH 7.4. Copolycarbonates and copolyurethanes with PEG 4000 in the polymer chain have slightly lower rates of hydrolysis. When the solubility of the polymer is low and the crystallinity

ISSN:0022-233X    

DOI:10.1080/00222338108056816

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor