Miscibility of poly(vinyl chloride) with poly(methyl-co-hexyl acrylate) and poly(methyl-co-2 ethyl hexyl acrylate)

Abstract

The miscibility and phase behavior in blends of PVC with poly(methyl-co-hexyl acrylate)[MHA] were studied. It was found that PVC is miscible with MHA copolymers having a HA volume fraction from 0.30 to 0.92 and MEH copolymers having an EH volume fraction from 0.30 to 0.83 at 100℃. By applying the mean field theory to the phase diagrams of these blend systems, segmental interaction parameters which represent the binary interaction between different monomer units were estimated. The calculated values reflect the fact that the miscibility window observed for PVC/MHA and PVC/MEH blend systems was attributed to the effect of repulsion between different monomer units within the copolymer. To investigate the effect of specific interaction on the miscibility for these blend systems, an attempt was also made to describe the blend interaction parameter as a function of polar group concentration in the acrylate copolymer. The blend interaction parameter values exhibit a s-shaped curve as a function of the weight fraction of C=O group in the copolymer, and the lowest blend interaction parameter value appears at about 0.24 C=O weight fraction.