Morphology and porosity of poly(vinylbenzyl chloride) beads containing styrene–ethylene, butylene–styrene triblock copolymer1Based on a paper presented at the Fifth International Meeting on Chemical Sensors, Rome, Italy, 11–14 July 1994.1

Abstract

Abstract Because crosslinked, porous poly(vinylbenzyl chloride) is an attractive substrate for sensors and actuators based on polymer swelling, its properties were studied as a function of formulation. Polymer beads were formed by suspension copolymerization of vinylbenzyl chloride and divinylbenzene in the presence of xylene/dodecane and Kraton G1652, a styrene–ethylene, butylene–styrene triblock copolymer. As polymerization proceeds, the dodecane phase separates forming aliphatic domains within the aromatic polymer. After polymerization, the xylene/dodecane is removed to yield a porous material. These materials were examined by scanning electron microscopy and mercury porosimetry. It was found that including Kraton G1652 in the formulation leads to morphologies with greatly increased surface area compared with morphologies observed without Kraton G1652. Formulations with 2% Kraton contained a large number of small pores in a continuous aromatic polymer matrix. Formulations with 8 and 14% Kraton have a morphology consisting of small connected spheres surrounded by empty void space.