PBT blends with rigid polymer and elastomer inclusions:: the effect of component type and reactivity on mechanical behaviour

The present study shows the potential of the poly(butylene terephthalate) (PBT) matrix to form ternary blends with well-balanced properties, analogous to Polyamide 6 (PA6) systems with a very fine (<100nm) separately dispersed rigid polymer (poly(styrene-co-maleic anhydride)) and elastomer (maleated ethylene-propylene elastomer). The use in PBT blends of maleated components analogous to those in the PA6 systems was much less effective, due to the presence of larger particles. Enhancement of all properties, including toughness, was found in the case of a blend containing at least one component with epoxide groups, such as rigid styrene-glycidyl methacrylate copolymer or elastomeric poly[ (ethylene) co-(methyl acrylate)-co-(glycidyl methacrylate)]. In this case, the reactive compatibilization of the epoxy-group-containing component caused refinement of particle size of the other component due to enhanced viscosity. As a result, more advantageous micromechanical behaviour of this ternary in comparison with the binary system occurs. The PBT matrix offers a similar potential to PA6 in synergistic influencing of both well-dispersed phases. This work supports the universality of rigid polymer-elastomer combination for the enhancement of the properties of pseudoductile polymers. (C) 2004 Society of Chemical Industry.