摘要:

The thermal stability of polyvinyl chloride (PVC) as one of the major manufacturing problems has been dealt with quite extensively for some decades. Apparently, there seems to be no remaining problem in processing PVC, because excellent stabilizers have been developed for use with it. However, there are still wide discrepancies among reported papers [1–14] on the mechanism of dehydrochlorination of PVC and the mechanism of stabilization by thermal stabilizers. The thermal decomposition of PVC is primarily a dehydrochlorination reaction [15], both in nitrogen and oxygen. However, it is a formidable task to summarize the reported results because of the difficulties associated with the characterization of prepared PVC. Therefore, improving the formulation from the economical and toxicological standpoint has been considered a real problem. Moreover, the explanation for the role of each additive in the field of processing has been done only through personal knowledge.

ISSN:1532-1797    

DOI:10.1080/15583726908545924

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Since the days of the highly flammable celluloid collar, many people have been searching for ways to fireproof synthetic elastomeric and plastic materials. Thus the patent literature discloses numerous examples of chemical agents claiming to make plastics flame-resistant. Many new polymers have also been developed that do not burn or are self-extinguishing after the igniting force has been removed. As a result, the use of polymeric materials, particularly by government agencies and industry, in applications such as structural components, adhesives, flexible sealants, electrical insulation, and fibers has grown enormously in recent years. However, serious fires in commercial buildings, homes, ships, and a space vehicle have again created much concern over the possible role that plastics might have played in these conflagrations. In addition, more attention is being given to the amount of smoke and toxic fumes that are evolved during the combustion of polymers. It is the object of this article to review and discuss the developments in this field during the past 2 years.

ISSN:1532-1797    

DOI:10.1080/15583726908545925

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

ISSN:1532-1797    

DOI:10.1080/15583726908545926

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The heats of polymerization for a number of monomers are shown in the Appendix. Since ΔHp= ΔE − P ΔV, if the volume change can be neglected, the heat of polymerization becomes equivalent to the change in internal energy of the molecule. The internal energy may be reduced in a number of ways, for example, by a release of steric strain or by a loss of π-electron energy.

ISSN:1532-1797    

DOI:10.1080/15583726908545927

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

ISSN:1532-1797    

DOI:10.1080/15583726908545928

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

ISSN:1532-1797    

DOI:10.1080/15583726908545929

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor