Nano, micro, and bulk structures in atactic polystyrene – syndiotactic polystyrene blends obtained in situ in presence of the CpTiCl3/SiO2/MAO catalysts (Cp – cyclopentadienyl, MAO – methylaluminoxane)
2013
Abstract CpTiCl 3 /SiO 2 /MAO (Cp = cyclopentadienyl, MAO – methylaluminoxane) catalysts, where the Al:Ti varies from 20:1 to 500:1, were used in styrene polymerization. Atactic – syndiotactic polystyrene blends (aPS–sPS) were obtained in situ , the morphology of which was investigated by means of scanning electron microscopy. The blends morphology changed according to the kind of catalytic centers: cationic and syndiotactic on the catalyst surface, which create individually atactic or syndiotactic polystyrenes forming specific blends containing nano or micro-forms: when the Al:Ti ranges from 50:1 and to 100:1 in the blends, there occur nano-sPS particles 40–120 nm in size, if the Al:Ti ⩾ 300:1, the filament of δ-sPS polymorph, is produced where the filament size ranged from 30 to 10 nm. A decay of this form leads to the formation of spherical sPS forms several hundreds of nm in size. When the Al:Ti ranges 20:1–50:1, blend rods of several dozen micrometers were obtained.
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