COMPATIBILIZATION OF BLENDS OF POLY(ETHYLENE-TEREPHTHALATE) AND LINEAR LOW-DENSITY POLYETHYLENE WITH THE IONOMER OF POLY(ETHYLENE-CO-METHACRYLIC ACID)

The effectiveness of the sodium ionomer of poly(ethylene-co-methacryli c acid) as a compatibilizer for poly(ethylene terephthalate)/linear lo w density polyethylene (PET/LLDPE) was investigated at various PET/LLD PE ratios and ionomer contents. The techniques used were optical and e lectron microscopy, dynamic mechanical spectroscopy, differential scan ning calorimetry and tensile tests. The tensile properties were charac teristic of mechanical compatibilization since all other techniques in dicated a phase-separated system. The PET/LLDPE ratio influenced the d egree of compatibilization obtained. Using moderate levels of the comp atibilizer (ca. 10 wt%), best properties were obtained at increased PE T levels. On the basis of previous findings on the compatibility of PE T/ionomer blends it is proposed that compatibilization should be attri buted to strong interfacial bonding at the PET/ionomer interphase. An attempt to predict ternary properties from binary blend data using the appropriate theory of mixtures was moderately successful.