The combined effects of a polymeric compatibiliser and nanoparticles on structure development and properties of polymer blends

This study investigates the combined effects of a polymeric compatibliser and clay nanoparticles on structure development and properties of a polymer blend. An immiscible polymer pair of polystyrene (PS) and poly (ethylene-co-vinyl alcohol) (EVOH) was selected as a model system and a random copolymer of Styrene and acrylonitrile (SAN) with 20 wt% acrylonitrile content was used as a polymeric compatibiliser. Cloisite 10A clay was used as a co-compatibilizer. Addition of the compatibilizer led to formation of a core-shell particle morphology where EVOH droplets were encapsulated by SAN layers. After addition of clay, it was observed that the morphology was altered drastically. SEM images revealed that incorporation of 10A clay in the ternary systems, promoted the formation of a grape-like morphology where EVOH droplets were encapsulated in bigger SAN domains and the final morphology was very close to a co-continuous type morphology. These observations were related to the affinity of the clays with each phase. It was proposed that 10A clay has mostly been located at the interface of SAN-EVOH pair which led to reduction in inter-droplet interfacial tension as evidenced by TEM. The mechanical properties of the hybrids were evaluated using tensile testing, so that a correlation between the morphology and properties could be established

Keywords:

Polymer Blends , Structure Development , Compatibilizer and Nanoparticles