Degradation Reactions in Silicone Polymers.
Abstract
This report is concerned with the preparation and thermal degradation of methyl and phenyl substituted siloxane polymers. There are three main experimental sections which are concerned respectively with poly(dimethyl-siloxane), poly(diphenylsiloxane) and poly(phenylmethylsiloxane). The volatile products of thermal degradation of poly(dimethylsiloxane) at temperatures from 200 C upwards, have been separated and estimated quantitatively using gas-liquid chromatography and shown to consist of cyclic trimer, tetramer, pentamer, hexamer, etc. in decreasing quantities. Infra-red spectral examination of the residual polymer suggests that crosslinking has occurred. At 160 C the molecular weight does not change, at 200 and 250 it increases to approximately double its initial value, while at 300, 350 and 400 C it increases initially but later decreases. The mechanism of thermal degradation of poly(dimethylsiloxane) is discussed in the light of these observations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1976
- Accession Number
- ADA050366
Entities
People
- I. G. Macfarlane
- N. Grassie
Organizations
- University of Glasgow