Interpolymer covalent induced miscibility of silicon-containing copolymer with styrene-based copolymers

Copolymer of 3-(trimethoxysilyl)propyl methacrylate (MSMA) with butyl metha crylate (BMA), 1, and copolymers of styrene (S) with various ratios of acry lic acid (AA), 2, were prepared via monomer-starved polymerization. Dynamic mechanical analysis (DMA) and atomic force microscope (AFM) were used to i nvestigate the blending behavior of these two polymers. For 50/50 (wt) blen ding systems, DMA measurements showed a shift of a two-separated glass tran sition temperature (T-g) inward to each other or only a broad T-g, dependin g on the AA content in 2. The domain sizes of 2-rich phase decreased with a n increase of the AA contents in 2, as observed by AFM. These results indic ated that improved miscibility of these two polymers were obtained, due to formation of interpolymer covalent of Si-O-CO links by reaction of methoxys ilane groups presented in 1 with carboxylic acid groups in 2.