摘要:

AbstractThe kinetics of copolymerisation of vinyl chloride with allyl chloride in chlorobenzene and in dichloroethane solvent have been studied by a dilatometric method. The compositon of the copolymers was determined by reduction with tributyltin hydride followed by infrared examination. Molecular weights obtained by g.p.c. enable as estimate of the transfer constant for degradative transfer to allyl chloride to be made for both the chlorobenzene and dichloroethane solvent systems. The results show that allyl chloride retards vinyl chloride polymerisation by degradative transfer and that the resulting radicals combine with the growing polymer chains. The dependence of copolymer composition on the composition of the monomer feed reveals that one of the pair of reactivity ratios associated with this reaction in either solvent has a negative value.

ISSN:0007-1641    

DOI:10.1002/pi.4980120202

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980120203

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractPaint films used to protect metalic surfaces are commonly polymeric in nature. The extent of protection offered by film depends on many factors including the characteristic electrical resistance behaviou and its effect on impeding local electrochemical processes. In the present work a range of polymeric coatings have been produced with systematically varied crosslinked density using an ultra‐violet light curing technique. Their electrical resistance behaviour in an environment of varying concentrations of KC1 electrolyte has been examined. It is demonstrated that there are signs of the beginnings of a mechanism changeover from “D‐type” to “I‐type” behaviour at higher levels of crosslink density thus giving some tenuous support to previously unproven hypotheses

ISSN:0007-1641    

DOI:10.1002/pi.4980120204

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractNaphthalene was reacted with various proportions of formaldehyde at different temperatures using sulphuric acid as the condensing agent. The products obtained in the early stages of the reaction consisted essentially of naphthalene units joined by ether and acetal bridges. However, as the reaction progressed the bridges lost oxygen, as water, to give methylene bridges while at the same time the softening points of the resins increased.

ISSN:0007-1641    

DOI:10.1002/pi.4980120205

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractPolymers have been widely used as catalysts or catalyst supports and the various applications can be categorised conveniently into four groups (a) catalysis by soluble linear polymers, (b) catalysis by ion exchange resins, (c) polymer‐supported ‘homogeneous’ metal complex catalysts and (d) polymer‐supported phase transfer catalysts. A brief review of each of these is given, with citation of some of the more recent and important examples which illustrate some of the basic principles i

ISSN:0007-1641    

DOI:10.1002/pi.4980120206

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractThe properties of ostensibly similar grades of polyvinyl alcohol‐acetate are often found to be drastically different: for example, the viscosity of a polyvinyl acetate latex prepared using polyvinyl alcohol in the emulsifier system was reduced by half when a different sample of polyvinyl alcohol was used, yet the polyvinyl alcohols appeared to be identical in most respects. However, when the {1H } −13C n.m.r. spectra were obtained under identical conditions it was found that the ratio of the intensities of the methine and methylene resonances differed. This is attributable to a difference in the extent of short‐chain non‐hydrolysable br

ISSN:0007-1641    

DOI:10.1002/pi.4980120207

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980120208

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980120209

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980120201

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY