New Types of Highly Elastic Substances, Vulcollans

Abstract

Abstract It is shown that new types of highly elastic products with remarkable properties can be obtained by a process of diisocyanate poly-addition, which involves the transformation of linear polyesters of glycols and dicarboxylic acids with an excess of certain special “expansive” diisocyanates in the presence of a very small proportion of water. The terminally bifunctional polyesters react first with the diisocyanate, with resultant lengthening of the chains. A network is subsequently developed from urea groups, which are formed from isocyanate groups and water, and which then react with the diisocyanate. The chemical mechanism of this process is discussed in detail. In addition, the processing and possible applications of this new class of elastomers is reviewed.