Novel semi-IPN through vinyl silane polymerization and crosslinking withinPVC films

Novel semi-IPN (interpenetrating polymer networks) were synthesized through vinyl silane modification of unplasticized poly(vinyl chloride) (PVC) film s using relatively low temperatures, relatively high vinyl silane contents, and several different processing routes. A free-radical initiator was used to promote reaction of the vinyl groups, and an aqueous acetic acid soluti on was used to promote the methoxysilane hydrolysis and condensation (HC) r eactions for siloxane crosslink formation. A gel consisting of silane alone was formed prior to the HC process, indicating the formation of a semi-TPN . The gel content following the HC process far exceeded the silane content, indicating a significant amount of PVC was entrapped by the silane network . This conclusion is supported by the homogeneous molecular structure and m orphology of the films. (C) 2000 John Wiley & Sons, Inc.