Grafting of vinyl polymers to carboxylated poly(arylene ether sulfone) utilizing barton ester intermediates and nitroxide mediation

Esters of N-hydroxypyridine-2-thione (Barton esters, BE) were appended to a carboxylated poly(arylene ether sulfone), PSF-COOH, backbone. Irradiation of the polymer bound Barton ester in monomer/DMF solution initiated a free radical graft polymerization at 25 degrees C without promoting concomitant homopolymerization. The following monomers were grafted to PSF backbones us ing this technique: styrene, methyl methacrylate, vinyl pyridine and acryla mide. Since the grafts are attached to the backbone by an ester linkage, th e graft segments were cleaved and subjected to independent characterization . Graft length is dependent upon the [BE]/[M], and the degree of BE substit ution on the backbone. Treatment of BE modified PSF with styrene in the pre sence of TEMPO afforded the corresponding TEMPO adducts, which were used to promote the controlled radical graft polymerization of styrene. (C) 2000 E lsevier Science Ltd. All rights reserved.