Aminosilane grafting of plasticized poly(vinyl chloride) II. Grafting and crosslinking reactions

The reaction of poly(vinyl chloride) (PVC) in a plasticized formulation, with N-(2-amino ethyl)—3-aminopropyl trimethoxy silane yielded silane-grafted PVC that was crosslinked by a hydrolytic mechanism. The grafting of the aminosilane was carried out during processing on a two-roll mill, followed by compression molding. The grafting and crosslinking reactions were followed by measuring the gel content and by observing the changes in concentration of different structures using Fourier transform infrared (FTIR). Syndiotactic structures in the PVC seemed to be more reactive than isotactic structures with respect to crosslinking. The changes in molecular weight distribution before and after crosslinking were also followed using gel permeation chromatography (GPC); increases in both M<INF>w</INF> and M<INF>n</INF> were found and were attributed to chain extension reactions. After crosslinking, the remaining soluble polymer was found to have a low molecular weight. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2121–2128, 1997