Chemically blended thermoplastic IPN(CBT-IPN) and mechanically blended thermoplastic IPN(MBT-IPN) were prepared by combining polymer Ⅰ

a linear styrene-butadiene-styrene(SBS) triblock copolymer with polymer Ⅱ

an ionomer prepared from a random copolymer of styrene and methacrylic acid(10: 1

by volume). Their morphology and glass transition behavior were investigated by transmission electron microscopy(TIM) and dynamic mechanical spectroscopy (DMS). The experimentel results showed that compatibility was increased after forming IPN from precursors and that CBT-IPN were more compatible than compositionally equivalent MBT-IPN.All of samples exhibitedd two glass transition temperature and two phases which separated from each other.Analysis of moduli data with the theories of Budiansky and Kerner disclosed dual phase continuity of polymer Ⅱ was decreased with increase of SBS content.