摘要:

AbstractThe polymerization of styrene (St) initiated by 1,4‐dimethyl‐1,4‐diphenyl‐2‐tetrazene (1c) is studied kinetically in benzene. The polymerization proceeds through a radical mechanism. The rate equation is as follows:Rp=k[1c]0,5[St]1,0. The overall activation energy for the polymerization of St is found to be 105,9 kJ · mol−1. The efficiency of the initiator is also calculated to be 0,67. On the basis of the results, the initiating ability ofN‐methylanilino radical

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830101

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractRing‐opening copolymerization studies were made on the systems cyclopentene (CPE)/ norbornene (NBE), cyclooctene (COE)/ norbornene, 1,5‐cyclooctadiene (COD)/norbornene, cyclopentene/cycloheptene (CHP), and cyclopentene/ 1,5‐cyclooctadiene using olefin metathesis catalysts.13C NMR spectra of the copolymers permit direct determination of the reactivity ratios in most cases, as well as the proportion ofcisdouble bonds in each type of dyad. For CPE/NBE, COD/NBE and CPE/CHP the reactivity ratios vary widely with the catalyst system and sometimes with the catalyst/cocatalyst ratio and method of mixing. There is no correlation between composition of the copolymer andciscontent. The copolymers show either a random or blocky distribution of monomeric units. The results are discussed in terms of a mechanism in which the metal carbenes formed in the propagation processes are initially coordinated to the polymer chain and can add further monomeric units stereospecifically while in this form. These propagation processes compete with a relaxation process leading to a metal carbene in which the polymer chain is no longer coordinated at the vacant site and which adds monomer in a less stereospecific fa

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830102

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractTo develop a new method for molecular design of functional polymers, polyamine macromers4, 10,and16were synthesized by lithium alkylamide catalyzed polyaddition reactions ofN,N'‐diethylethylenediamine(1),1,4,10,13‐tetraoxa‐7,16‐diazacyclooctadecane(7),and piperazine(12)to 1,4‐divinylbenzene(2),respectively. Copolymerization of these macromers with styrene gave a new type of graft copolymers6, 11,and19,having polyamine grafts. Copolymerization data indicated that the length and number of graft chains could be controlled by adjusting the molecular weight of the macromer and its initial concentration in the copolymerization system. The crystallinity of16, 19,and other macromers(17, 18)having piperazine units was

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830103

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractMethyl methacrylate (MMA) was copolymerized with acrylamide,N‐methylacrylamide,N,N‐dimethylacrylamide, 1‐vinyl‐2‐pyrrolidone, 4‐vinylpyridine, and 2‐dimethylaminomethyl methacrylate in 1,4‐dioxane solution at 65°C, using AIBN as initiator, to yield copolymers with comonomer contents between about 5 and 50 mole‐%. The monomer reactivity ratios were evaluated. The copolymerizations are in general non‐azeotropic and non‐ideal. The amine group containing comonomers are preferentially incorporated in relation to MMA, but MMA is preferentially incorporated in relation to the amide group containing comonomers. The average molecular weights of the copolymers, with the exception of theN,N‐dimethylacrylamide copolymer, decrease with increasing comonomer concentration, especially in the case of the amine group containing comonomers. The increasing content of amide and amine group containing monomeric units in the copolymers influences the adsorption of the polymers on an iron oxide red pigment, the dispersion stability, as well as the adhesion of the polymer coatings on steel plates and th

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830104

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractPoly(oxovinyl sulfide)s3were prepared by vinylogous nucleophilic substitution polymerization of bis(3‐chloroacryloyl) derivatives of benzenes (1aand1b) with 4,4′‐oxydibenzenethiol(2). The synthesis involves solution polycondensation and two‐phase polycondensation with phase transfer catalysts. Polymers having inherent viscosities in the range of 0,2–0,7 dl·g−1were obtained quantitatively by both methods. They are soluble in concentrated sulfuric acid, dichloroacetic acid, andm‐cresol, and practically insoluble in polar aprotic solvents and common organic solvents. Thermogravimetric studies in both air and nitrogen atmospheres indicated that the decomposition temperatures for 10% weight loss of the polymers we

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830105

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractEquations to calculate the density of branching arising from chain transfer to polymer with initiator radicals in terminally functional polymers of low molecular weight were derived for various polymerization conditions. The branching density was shown to be affected by the feed procedure. The relative amount of branching was found to be lower with a single addition of monomer and initiator than with continuous feed of initiator during the reaction. These conclusions were confirmed experimentally.

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830106

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractWith the aid ofD‐glyceric acid as a template, an amino‐ and a boronic acid group, respectively, were introduced in a defined steric arrangement into polymers. For this, the monomerD‐N‐(4‐vinylphenyl)carbamoylethylenedioxy(4‐vinylphenyl)borane (1) was copolymerized into macroporous polymers under various conditions. The templateD‐glyceric acid was split off from the polymer with 20% HCl in methanol. The specificity of the polymers obtained with one amino‐ and one boronic acid group, respectively, per cavity was derived from their ability to resolve racemic glyceric acid. Racemic resolution was also observed on equilibration of the polymers withD,L‐methyl glycerate andD

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830107

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractSulfomethylated resins are prepared by polymer analogous reactions, starting from macroporous poly(styrene‐co‐divinylbenzene) matrices. Different reaction paths are discussed and used in the synthesis. Sulfomethylation can be achieved by reaction of a chloromethylated resin with dimethyl sulfide and sodium sulfonate or alternatively by oxidation of polymer‐bound thiol groups. Both methods give high conversions as shown by IR spectra and titration of the sulfonic acid groups. Poly[1‐(4‐hydroxysulfomethylphenyl)ethylene](3)is obtained by reaction of poly[1‐(4‐hydroxyphenyl)ethylene] (2) resin with formaldehyde/sodium sulfonate. The thermal stability, catalytic activity, and ion exchange equilibria of the sulfomethylated resin are

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830108

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe synthesis of 6‐vinylchrysene (1) starting from chrysene is described. The study of the polymerizability of1by conventional radical, cationic, and Ziegler‐Natta procedures indicates the tendency of1of give head‐to‐tail polymeric products with a similar degree of polymerization independent of the catalytic system. Copolymers of1with optically active (−)‐menthyl acrylate (2), (−)‐menthyl methacrylate (3), and (S)‐4‐methyl‐1‐hexene (4), were also prepared. No apparent copolymerization of1with optically active alkyl vinyl ethers occurred by cationic initiation. Spectroscopic and chiroptical properties are presented to support the formation of copolymer macromolecules. Finally, the differential dichroic absorption measurements allow one to stress that in optically active vinylaromatic copolymers the extent of preferential asymmetry, induced by the dissymmetric field of units derived from the optically active nonaromatic comonomer, increases with increasing bulkiness and polarizability of the

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830109

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractRadical copolymerizations of mono‐ and di‐l‐menthyl fumarate (1and2) with styrene (St) were carried out, and the copolymers were hydrolyzed with potassium hydroxide. The products show still optical activity even after the removal of the optically active side chain, because of an introduction of asymmetry into the main chain of the copolymer. The specific rotation per one of the diad sequences of hydrolyzed poly(1‐co‐St) was the same as that of hydrolyzed poly(2‐co‐St). The mechanism of asymmetric induction and the position of the new asymmetric center are discussed based on the measurements of UV spectra, optical rotation, and circu

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830110

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY