Silacyclobutane functional polymers and their production.

摘要

The silacyclobutane functional polydiorganosiloxane copolymers of the invention have the following structure: <CHEM> wherein M is selected from <CHEM> wherein R<a>, R<b>, R<c>, R<d>, R<e> and R<f> are independently monovalent radicals; m, n, p and x are integers of from 0 or more, with the proviso that there is at least one silacyclobutane group in the copolymer. The copolymer can be made by reacting a hydroxyl endblocked polydiorganosiloxane with either a difunctional chain extending silacyclobutane or with a monofunctional chain stopper or a mixture of chain extender and chain stopper. The copolymer can be made into curable compositions by use of suitable catalyst.