(174e) Effect of Amphiphilic Surfactants on the Properties of Polyethylene – Graphene Nanocomposites

Compatibilizers of different chemical structures and specifications were used to enhance the filler exfoliation in nanocomposites of polyethylene and graphene oxide prepared by melt mixing route. The mass fractions of filler and compatibilizers were held constant in the nanocomposites in order to attribute the observed composite properties to compatibilizer type and its interactions with filler surface. The mechanical performance of the compatibilized nanocomposites was observed to be better than PE/G nanocomposites due to enhanced extent of filler exfoliation and distribution. Highest increase of 45% in tensile modulus and 13% in peak stress was observed in the composites. Overall, from the mechanical, rheological, thermal and calorimetric properties, the compatibilizers with best performance were ethylene acrylic acid copolymer (EAA) and chlorinated polyethylene (CPE25). The extent of EAA was also varied in the nanocomposites in order to attain an optimum amount of comaptibilizer in the composites suitable for achieving enhancement in properties. The extent of filler exfoliation was observed to increase with increasing EAA content thus confirming positive interactions between EAA and graphene oxide, though no specific chemical interactions could be detected. The composite properties were observed to reach maximum around 7.5 wt% EAA content, followed by reduced performance due to extensive matrix plasticization. The observed behaviors were a result of interplay of opposing factors like filler exfoliation due to compatibilizer addition and matrix plasticization due to its lower molecular weight, thus, the observed optimum comaptibilizer amount is specific to the compatibilizer. The generated composites had also much superior performance than the composites generated with commonly used fillers like layered silicates.