STUDIES ON BLENDS OF IONOMERS

Blends of the zinc salt of poly(ethylene-co-methacrylic acid) (ZnEMA) and the zinc salt of sulfonated ethylene-propylene-diene monomer rubbe r (SEPDM), show thermoplastic elastomeric behaviour. The physical prop erties of the blends are greater than that predicted by the additivity rule. Results of dynamic mechanical analyses show ionic transitions i n addition to T-g in the case of neat polymers and blends. Dielectric thermal analyses show that the activation energy due to ionic groups i n dipolar relaxation is highest in the case of the 50/50 ZnEMA/SEPDM b lend, presumably due to formation of interfacial ionic aggregates in t he blend, evidence of which was obtained by infra-red spectroscopic st udies. Reprocessability studies in the Monsanto processability tester show that the blend could be reprocessed (that is, extruded up to thre e cycles) like a thermoplastic without deterioration in strength. Copy right (C) 1996 Elsevier Science Ltd.