Blends of immiscible polymers having novel phase morphologies

摘要

Unique phase morphologies of incompatible thermoplastic polymers, including a higher melting temperature polymer and a lower melting temperature polymer that has been sufficiently chemically compatibilized to form a stable interface in a two-phase system, are achieved by pre- melting the higher melting temperature polymer, adding the compatibilized lower melting temperature polymer in solid form thereto, and thereafter melting the lower temperature polymer with mixing. In particular, in poly(ethylene vinyl alcohol)/modified polyolefin systems, compositions containing between about 35 and about 55 wt. percent EVOH are formed in which the poly(ethylene vinyl alcohol) exists as a continuous phase and the modified polyolefin exists as discrete domains dispersed therein. Such blended compositions have gas barrier properties comparable to homogeneous poly(ethylene vinyl alcohol).