CASTING SOLVENT EFFECT ON CRYSTALLIZATION BEHAVIOR OF POLY(VINYL ACETATE) POLY(ETHYLENE OXIDE) BLENDS - DSC STUDY

摘要

Poly(vinyl acetate) (PVAc)/poly(ethylene oxide) (PEG) blends were prepared by casting from either benzene or chloroform. The solvent effects on the crystallization behavior and thermodynamic properties of the blends were studied by the differential scanning calorimeter ( DSC). Two grades of PEO with different molecular weights (PEO200 with M(w) = 200,000 g/mol and PEO2 with M(n) = 2000 g/mol) were used in this work. The thermal analysis revealed that the blends cast from either benzene or chloroform were miscible in the molten state. The crystallization of PEO in the benzene-cast blends was more easily suppressed than it was in the chloroform-cast blends. Furthermore, the benzene-cast blends showed a greater negative value of Flory-Huggins interaction parameter than those cast from chloroform in the PVAc/PEO200 polyblend system. It was supposed that the benzene-cast blends had more homogeneous morphology. (C) 1997 John Wiley & Sons, Inc. [References: 37]