ENTHALPIES OF MIXING IN POLYMER BLENDS OF CHLORINATED POLYMERS - APPLICATION OF A GROUP-CONTRIBUTION METHOD

A modified Guggenheim quasichemical method (MGQ) has been applied to c alculate enthalpies of mixing in mixtures based on chlorinated polymer s such as poly(epichlorohydrin) (PECH) or poly(vinyl chloride) (PVC). The required parameters have been determined from experimental heats o f mixing in mixtures of model compounds. Using the MGQ method, enthalp ies of mixing of PECH/ester containing polymer mixture's and PVC/polyo xide blends have been simulated. In PECH/ester containing polymer blen ds, the MGQ method gives an adequate picture of the evolution of the m iscibility with the polyester CH2/CH2COO ratio. Similarly, in PVC/poly oxide blends, the variation of the heat of mixing along the polyoxide family seems to agree with the miscibility window of these blends. How ever, in PVC/poly(ethylene oxide) blends, the MGQ method was not able to predict accurately the experimentally observed dependence of the mi scibility on the composition.