SYNTHESIS AND CRYSTALLIZATION OF SYNDIOTACTIC RANDOM COPOLYMERS OF STYRENE AND P-N-BUTYLSTYRENE AND OF SYNDIOTACTIC POLY(P-N-BUTYLSTYRENE)

The metallocene-catalyzed syndiospecific synthesis of the new homopoly mer of p-n-butylstyrene and its random copolymers with styrene is repo rted. The crystalline morphology of the resulting polymers is studied by means of atomic force microscopy (AFM), wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), and light microscopy . Copolymers with relatively small p-n-butylstyrene content are crysta llizable from the melt. It is shown that under these crystallization c onditions the alpha-modification is favored relative to the beta-modif ication (both modifications known from syndiotactic polystyrene) with increasing p-n-butylstyrene content. The crystalline morphology is bui lt up by crystalline slices formed by broad lamellae. The equilibrium melting temperature of the copolymers decreases with increasing p-n-bu tylstyrene content. Furthermore, the crystallization of quenched, amor phous samples during thermal annealing below the melting temperatures (cold crystallization) or induced by solvents is studied. The syndiota ctic p-n-butylstyrene homopolymer has two modifications characterized by WAXS which are different from all modifications of syndiotactic pol ystyrene or syndiotactic p-methylstyrene homopolymer.