Compatibilization of PP/Vectra B "in situ" composites by means of an ionomer

Ionomer addition has been investigated as a compatibilizer for the immiscible polypropylene (PP)/Vectra B 950 (VB). Both modified and unmodified blends as a reference, with VB contents up to 30% were obtained by direct injection moulding. The crystallinity of PP/VB was barely influenced by the presence of the ionomer. The compatibilization leads to the presence of thinner fibres that broke during testing. Compatibilization reduced toughness, but at VB contents of 15 wt% or more, both the modulus of elasticity and the tensile strength significantly increased with respect to the uncompatibilized blends. The properties of both compatibilized and uncompatibilized blends, as a whole, were similar in the case of PP modified by either maleic anhydride or ionomer addition. However, favourable experimental conditions such as thinner specimens or higher compatibilizer content were used in the case of maleic anhydride modified PP. This indicates a more important positive effect: on compatibilization by means of ionomer addition. (C) 2000 Elsevier Science Ltd. All rights reserved.