Synthesis and characterization of styrene-butadiene block copolymer/silicate hybrid materials via the sol-gel process I. Four-arm star styrene-butadiene block copolymer/silica hybrids

Novel hybrid materials incorporating four-arm star styrene-butadiene block copolymer (SB-4A) with tetraethoxysilane (TEOS) have been successfully prepared by a sol-gel process. The properties, microstructure, and dynamics of the hybrid materials were investigated in detail by means of dynamic mechanical analysis (DMA), thermogravimetry (TG), and NMR techniques. The results indicate that the properties of the hybrids strongly depend on the TOES content and the silica networks prefer to form in the polystyrene (PS) domains. There exists an optimum range of TEOS content, in this work 30-50% by weight, within which the properties of the hybrids obtained were well improved: storage modulus increases, thermal stability raises, and the high-temperature T-g shifts to higher temperature. Si-29 NMR spectrum shows that in the hybrids with well improved properties silica networks formed with Q(4) in the greatest abundance.