Synthesis of Syndiotactic-polystyrene Based Porous Polymers by Polymerization-Crystallization Induced Phase Separation in Poor Solvent

Syndiotactic-polystyrene based porous polymers were obtained by polymerizations of styrene (St), 4-methyl styrene (MSt), or 4-tert-butyl styrene (BSt) and copolymerization of St/MeSt, St/BuSt, or St/divinylbenzene (DVB) using a half metallocene catalyst, pentamethyl cyclopentadienyl titanium trichloride (Cp*TiCl3), combined with methylaluminoxane (MAO) as a co-catalyst in a mixture of toluene and hexane (50/50 vol./vol.). The reaction systems turned opaque with progress of the polymerizations accompanied by phase separation. Bulk densities of the resultant polymers were much less than that of the bulk polystyrene. Scanning electron microscopy (SEM) images of the polymers showed a porous structure formed by networked fibers.