On the hydrosilation of SBS and the properties of hybrid materials from hydrosilated SBS and silica

Triethoxysilyl functionalized poly(styrene-b-butadiene-b-styrene) (TS-SBS) was prepared by the hydrosilation of carbon-carbon double bonds in a four-a rm star SBS and was obtained by coupling the growing styrene-butadiene bloc k copolymer with SiCl4 and with triethoxysilane in toluene at 70 degreesC u sing cis-bis(diethyl sulfide) platinum (II) dichloride (CPD) as a catalyst. The reactivity, in increasing order of hydrosilation, for these three kind s of double bonds was trans-1,4- < cis-1,4- < vinyl-. The molecular weight of TS-SBS decreased with time when it was heated with CPD in toluene at 70 OC. The gelation time of the sol-gel solution, TS-SBS/TEOS, was influenced significantly both by the molecular weight of and the attaching of the trie thoxysilyl groups on the TS-SBS. After undergoing an in-situ sol-gel proces s, the TS-SBS/TEOS became an organic-inorganic hybrid material, TS-SBS/SiO2 . The dynamic mechanical property and elongation of hybrids of the differen t molecular weights of TS-SBS and silica contents were studied in detail.