Interpenetrating polymer networks of poly(styrene-co-4-vinylphenyldimethylsilanol) and poly(N-vinylpyrrolidone): a new approach to network formation

Blends consisting of poly(styrene-co-4-vinylphenyldimethylsilanol) (ST-VPDMS) and poly(N-vinylpyrrolidone) (PVPr) were studied by glass transition temperature measurements and FTi.r. spectroscopy. It was found that ∼4 mol% of VPDMS monomer units had to be incorporated into styrene copolymers in order to form miscible blends with PVPr. Mutual precipitates in the form of interpolymer complexes were obtained for the ST-VPDMS copolymers containing more than 34 mol% VPDMS. Semi-interpenetrating polymer networks (semi-IPNs) were prepared from ST VPDMS/PVPr interpolymer complexes by self-condensation of dimethylsilanol groups when the copolymers contained more than 60 mol% VPDMS, and thus provided a new route to IPN formation without the presence of any external crosslinkers or catalysts.