Crystallization of partially miscible linear low-density polyethylene/poly(ethylene-co-vinylacetate) blends

Miscibility and crystallization of linear low-density polyethylene (LLDPE)/poly(ethylene-co-vinylacetate) (EVA) blends were investigated by optical microscopy (OM) and differential scanning calorimetry (DSC). It was found that there existed liquid-liquid phase separation (LLPS) below 220 degreesC over the whole composition. However, the depression in the crystallization temperature, melting temperature and equilibrium melting temperature of LLDPE all indicated that this polymer pair was partially miscible. The crystallization and melting behavior of LLDPE were determined by the dilute effect of non-crystalline EVA and the probable co-crystallization of parts of EVA chains with LLDPE chains. The crystallization and melting behavior of EVA was determined by the competence between a nucleation effect of LLDPE crystals and partial miscibility between this polymer pair, which was different from that of LLDPE. (C) 2004 Elsevier B.V. All rights reserved.