Novel blends of alternating propene-carbon monoxide copolymers and styrenic copolymers

Alternating propene-carbon monoxide copolymers (P-CO) were melt-blended wit h polystyrene, po ly(styrene-co-aclylonitrile) (SAN), and with po ly(styren e-co-maleic anhydride) (SMA). P-CO forms homogeneously miscible blends with SAN containing 25 wt% AN at the investigated blend compositions. The trans parent blends have single, intermediate glass transition temperatures that fit the Fox equation. The elastic properties of P-CO at room temperature di sappear upon blending with SAN because the T-g is driven above RT. Polystyr ene and SMA are not miscible with P-CO and form heterogeneous blends with t wo glass transitions. This demonstrates that both the polarity of the styre nic copolymer and the nature of the comonomer govern its phase behavior.