Abstract: Poly(vinyl acetate)/poly(methacrylate)interpenetrating polymer networks(PVAc/PMA IPNs)and semi-IPNs were swollen in toluene under the thermodynamic condition of phase separation,or the PVAc component of the IPNs was alcoholyzed to decrease the compatibility between two components.No phase separation was found in IPNs and semi-IPNs with high crosslink density of network I.It is indicated that the mutual entanglements between the two networks is permanent physical entanglements and the phase of the IPNs is stable.

Key words: Poly(vinyl acetate)/poly(methaerylate) 1PNs, Permanent entanglement Compatibility