Abstract: A series of polyurethanes and poly(styrene-methyl methacrylate-methacrylic acid) interpenetrating polymer networks(IPNs) were characterized using stress-strain analysis,dynamic mechanical spectroscopy, transmission electron microscopy and thermal behavior measurements. The results of dynamic mechanical behavior and morphology show that the phase separation of the IPNs is serious.The IPNs have two T_g values with different extent of shift, indicating the mixing of two components in some extent. The formation of IPNs has improved their mechanical properties. It is suggested that the Si-MMA-MAA segments act as radical scavengers in the polyurethane degradation.

Key words: interpenetrating polymer network, dynamic mechanical spectrum, polyurethane, morphology