Study On Stereocomplexation Of Isotactic CO₂-based Terpolymers

Crystalline polycarbonate stereocomplexes can be formed from the cocrystallization of two opposite enantiomeric polymers through an interlocked orderly assembly.The thermodynamic properties are significantly different from that of the component enantiomeric polymers:an enhanced melting temperature or the transformation from amorphous state to crystallable materials.However,most study about stereocomplexes formation only focused on enantiopure copolymers,and no reports regard isotactic terpolymers.There are completing reactions when different epoxides are copolymerized with CO₂,and this can result in different morphologies,such as random and gradient structures which can be identified by measuring reactivity ratios.Herein,reactivity ratios of 15 types of terpolymerizationshave been determined and 6 terpolymers owned random structures.A detailed assembly experiment was performed for the model random terpolymer of2,3-butylene oxide/1,2-epoxy-4-cyclohexene/CO₂?PCEBC?.A possible interaction mode between different enantiopure polymers was proposed,which was proved by assembly of block polymers with different configurations.