view:25240 Last Update: 2018-10-20
Sohrab Rahmani and A.A.Entezami|
Grafted polydimethylsiloxane onto syndiotactic poly (styrene-co-p-methylstyrene): synthesis and characterization
پلی دی متیل سیلوکسان پیوندزده شده برروی کوپلیمر سیندیوتاکتیک استایرن-پارامتیل استایرن: سنتز و شناسایی
Syndiotactic polystyrene-graft-polydimethylsiloxane copolymers were synthesized using a two-stage process and characterized. First, the syndiotactic polystyrene copolymer, poly(styrene-co-p-methylstyrene) was prepared by the copolymerization of styrene and p-methylstyrene with cyclopentadienyltitanium trichloride/methylaluminoxane catalyst. The obtained copolymer was grafted with polydimethylsiloxane by the anionic ring-opening polymerization of hexamethylcyclotrisiloxane with a metallation reagent. The effect of the solvent on the degree of grafting in the obtained copolymers was investigated. 1H NMR, 13C NMR, FTIR spectroscopy and differential scanning calorimetery (DSC) were used to examine the structure and thermal behavior of the copolymers. The degree of graft was higher in THF. The melting, crystallization and glass-transition temperatures of the graft copolymers decreased with increasing degree of graft in the copolymers.