Morphology of reactive PP/PS blends with hyperbranched polymers

Abstract

AbstractTo study the efficiency of different mechanism for reactive compatibilization of polypropylene/polystyrene (PP/PS) blends main chain or terminal functionalized PP and terminal functionalized PS have been synthesized by different methods. While the in‐situ block and graft copolymer formation results in finer phase morphologies compared to the corresponding non‐reactive blends, the morphology development in the ternary blend system PP/PS + HBP (hyperbranched polymer) is a very complex process. HBP with carboxylic acid endgroups reacts preferably with the reactive sites of the oxazoline functionalized PS (PS‐Ox) and locates mainly within the dispersed PS‐Ox phase. A bimodal size distribution of the PS‐Ox particles within the oxazoline modified PP (PP‐Ox) matrix phase is observed with big PS‐Ox particles (containing the HBP as dispersed phase) and small PS‐Ox particles similar in size like the unimodal distributed particles in the non‐reactive PP‐Ox/PS‐Ox blends. Factors influencing the morphology are discussed.