PHASE-RELATIONS IN BLENDS OF POLYVINYL-CHLORIDE) WITH COPOLYMER OF ETHYLENE-VINYL ACETATE AND THE EFFECTS OF THERMAL STABILIZERS

Further investigations of the system PVC-EVA, with wide line NMR, have shown that the phase relations differ for graft-polymerized samples and non-grafted samples prepared by milling the polymer components together. The phase relations of the grafted products are not appreciably changed by different types of processing and heat treatments. In the non-grafted samples, considerable phase separation is observed by heat treatment at the normal temperatures of processing. It is also shown that the metal-laurates, normally used for thermal stabilization, have good solubility in the PVC-phase and that co-stabilizers of phosphites and epoxides show considerable solubility in the EVA-phase. By heat treatment of milled products at the processing temperature, the co-stabilizers are to some degree transferred from the PVC- to the EVA-phase. © 1979.