Immiscible polymer blends compatibilized with reactive hybrid nanoparticles: Morphologies and properties

Abstract

Hybrid nanoparticles (NPs) having both reactive epoxide groups (from polyhedral oligomeric-silsesquioxane (POSS) grafts) and long poly(methyl methacrylate) (PMMA) chains, POSS(epoxy)x-g-PMMAy, were synthesized and used as reactive compatibilizers for immiscible polyvinylidene fluoride/poly(l-lactide) (PVDF/PLLA) (50/50) blends. It was anticipated that the NPs would react with the PLLA during melt mixing and would be located solely at the PLLA/PVDF interface because the PMMA side chains and the in-situ grafted PLLA chains would entangle with the PVDF and PLLA phases, respectively. However, effective compatibilization was only achieved by first blending the NPs with the PLLA followed by melt mixing with the PVDF. Elemental mapping images indicated that the NPs had a greater affinity for PVDF than for PLLA and were encapsulated in PVDF during one-step melt mixing or initial mixing with PVDF. The affinity of the compatibilizer with the blend components is therefore critically important for the effective compatibilization of immiscible polymer blends.