The synthesis of pseudo- and semi-interpenetrating polymer networks (IPNs) based on poly-dimethylsiloxane (PDMS) and polystyrene (PS) is described. IPNs were obtained by simultaneous and in situsequential synthesis procedure. The preliminary studies on IPNs properties such as transition temperature

microphase separation and mechanical behaviors have been carried out by using differential scanningcalorimetry (DSC) and scanning electron microscopy (SEM). The experimental evidence clearly showed thatsemi-IPNs obtained by sequential synthesis procedure have higher interpenetrating extent than pseudo-IPNs synthesized by simultaneous procedure.Over the full composition

the PDMS/PS IPNs are immiscible.The pseudo-IPNs microphase separation can be greatly subdued through are formation of grafting bonds between two networks as well as the kinetic rate-matching of the individual network crosslinking.