Thermal and mechanical properties of silane-crosslinked poly(vinylchloride)

A comparative study has been made of the crosslinking of plasticized PVC by grafting of gamma-aminopropyltriethoxysilane (ASD and sodium gamma-mercaptopropyltrimethoxysilane (NaMSi) during processing. The influence of type of reagent and concentration, and the rheological behavior were investigated to obtain a crosslinked material with improved mechanical properties and good thermal stability. Depending on the reagent concentration, different gel contents, ranging from 0-100%, were obtained with both reagents. For all crosslinked systems the mechanical properties above T-g were improved. In the case of ASi-crosslinked PVC, the thermal stability deteriorated significantly but, for NaMSi-crosslinked PVC, thermal stability remains close to that of raw PVC, and the separation of the grafting and crosslinking processes is more viable in this case. (C) 1998 John Wiley & Sons, Inc.