摘要:

Graft polymerization of 2-hydroxyethyl methacrylate was made onto plasma pretreated fabrics of cotton, silk, and polyester. Homopolymerization also took place during the graft polymerization, but the percent of the homopolymer formation was comparatively small. Therefore, kinetic analyses of graft polymerization were undertaken based on the first-order reaction of the monomer. Through a comparison of the rate constants which were obtained from the rate equation of the graft polymerization of 2-hydroxyethyl methacrylate, the dependence of plasma pretreatment on various factors and the resulting polymerization were clarified. Polymerizability was compared to that obtained with the Ce(IV) catalyst and without catalysts.

ISSN:0022-233X    

DOI:10.1080/00222339108052100

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The synthesis of a linear polymer having a tertiary amino group in a part of the main chain has been attempted by several methods. However, it was difficult for the linear polyamine to form because of the complicated reaction of the amino group. In the polymerization of weakly basic cyclic amines, e.g., 1-cyanoethylazetidine or 1-cyanoethylaziridine, high molecular weight polymers, poly-1-cyanoethyltrimethyleneimine (poly-CET) and poly-1-cyanoethyl-ethyleneimine (poly-CEE), were obtained. An attempt was made to convert poly-CET and poly-CEE into poly(l-benzylalkyleneimine)s (poly-BET and poly-BEE). Linear poly-BET was prepared by the alkylation of poly-CET (MW about 6000) with benzylbromide, followed by the elimination of the cyanoethyl group of polymer by heating. The poly-BET obtained was a white, greasy substance with a molecular weight of about 5000; its structure was determined by NMR spectroscopy. The cyanoethyl groups were replaced completely by benzyl groups. However, poly-BEE with a complete exchange to benzyl group was not obtained from poly-CEE due to the remaining cyanoethyl groups. Residual cyanoethyl groups replaced about 40% of the amino groups in poly-CEE.

ISSN:0022-233X    

DOI:10.1080/00222339108052101

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The photodegradations of various heterophasic ethylene-propylene (E-P) copolymer films were studied at 30 and 55°C in air for varying time intervals. The photochemical behavior of E-P copolymers is quite different from amorphous polypropylene and polyethylene homopolymers but resembles that of isotactic polypropylene. The nonvolatile products in photooxidized copolymer films have been quantitatively identified by infrared analysis. The kinetics and general oxidation mechanism scheme for E-P copolymer are presented. The identification of γ-lactone is an indication of the importance of an intramolecular back-biting process. The overall functional group distribution is found to differ from that in polyethylene and E-P copolymers.

ISSN:0022-233X    

DOI:10.1080/00222339108052102

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Chain radical polymerization with direct photoinitiatlon or thermal initiation and constant monomer concentration has been theoretically studied by dealing precisely with the kinetic differential equations. The expressions for molecular size distribution, number- and weight-average degrees of polymerization, and their dependence on the reaction conditions are derived in analytical form. A computation program allowed easy calculation of these parameters concerned with the resultant polymer.

ISSN:0022-233X    

DOI:10.1080/00222339108052103

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Free radical solution copolymerization of phenyl methacrylate andN-vinyl-2-pyrrolidone was carried out using benzoyl peroxide in 2-butanone solution at 70°C. The composition of the copolymer was determined using1H-NMR spectra by comparing the intensities of aromatic protons to that of total protons. The results were used to calculaie the copolymerization reactivity ratios by both the Fineman-Ross (F-R) and Kelen-Tüdös (K-T) methods. The reactivity ratios arer1= 4.49 ± 1.27 andr2= 0.05 ± 0.09 as determined by the K-T method. These values are in good agreement with those determined by the F-R method. The FT-infrared and13C-NMR spectra of the copolymer are discussed.

ISSN:0022-233X    

DOI:10.1080/00222339108052104

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Rates of initiation, dimerization, and first propagation steps originating from the hydrated electron and hydroxyl radical reactions with 3,3-dimethylacrylic acid monomer have been investigated using the technique of pulse radiolysis. The initiation step for the protonated monomer is found to be faster than that of the deprotonated form. The dimerization step is about two orders of magnitude faster than the first propagation step. Radical species are more reactive than the corresponding radical-anionic species, and the β-protonated electron adduct to the monomer is found to propagate faster than other electron adduct species. The different transient species have been characterized by their absorption spectra, λmax, extinction coefficient, pK, and redox behavior. Based on these observations, the most probable structures are suggested.

ISSN:0022-233X    

DOI:10.1080/00222339108052105

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Cationic copolymerizations of epichlorohydrin (ECH) (chloro-methyl oxirane) with styrene oxide (SO) (phenyl oxirane) and with 1,2-cyclohexene oxide (CO) (7-oxabicyclo [410] heptane) were carried out at 50°C by employing the salt triphenylmethyl hexachloro-antimonate (HC) (Ph3CSbCl6) as initiator. NMR spectra before and after attempted extractions of the polymeric products indicated that the resulting polymeric products were true copolymers and not mixtures of the respective homopolymers. Monomer reactivity ratios for both pairs of comonomers were determined; for one pair the values werer1(ECH) = 3.29,r2(CO) = 0.16 and for the second pairr1(ECH) = 0.57,r2(SO) = 0.16.

ISSN:0022-233X    

DOI:10.1080/00222339108052106

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Ferrocene (Fc)-sensitized photopolymerizations of vinyl monomers such as methyl methacrylate (MMA), acrylonitrile (AN), styrene (St), and isobutyl vinyl ether (IBVE) have been investigated by means of kinetic and spectroscopic analyses. The sensitizing effect of Fc has been found to be specific for AN; Fc acts as a sensitizer for AN but not for the other monomers. In the presence of carbon tetrachloride (CCl4), Fc is an effective sensitizer for MMA, AN, and IBVE, but it acts as an inhibitor for St. The polymerizations of AN by Fc and of MMA by Fc/CCl4proceed by a radical mechanism, whereas the polymerization of IBVE by Fc/CCl4proceeds in a catonic fashion. Kinetic studies gave the following relationships:Rp=k1[Fc]0.38[AN]1.7for the polymerization of AN by Fc in dimethylformamide;Rp=K2[Fc]0.48[CCl4]0.42[MMA]1.5for the polymerization of MMA by Fc/CCl4in benzene. Spectroscopic analysis indicated that the charge-transfer complexes are formed between Fc and a monomer or CCl4. The initiating species of the polymerizations are produced by the photochemical dissociation of the complexes.

ISSN:0022-233X    

DOI:10.1080/00222339108052107

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Equations correlating sequence distributions of nonhomogeneous first-order Markovian copolymer systems have been derived. For systems where (r1r2) differs by a factor of 2 from unity, a cubic power series approximation in polymer composition is necessary to predict triads to a standard deviation of ∼ 0.001–0.003. This precision holds over fairly broad ranges of (r1r2) and distribution function moments. Prediction of kinetic factors from sequence distribution data requires such precision that any derived data are questionable. Where two catalysts are involved, at least one of which is non-Bernoullian, there does not appear to be a practical way to derive kinetic data from triad sequences. Such systems can simulate homogeneous Bernoullian systems very closely.

ISSN:0022-233X    

DOI:10.1080/00222339108052108

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0022-233X    

DOI:10.1080/00222339108052099

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor