Processing and assessment of high-performance poly(butylene terephthalate) nanocomposites reinforced with microwave exfoliated graphite oxide nanosheets

To improve the physical properties of poly(butylenes terephthalate) (PBT), a series of nanocomposites based on PBT and microwave exfoliated graphite oxide nanosheets (MEGONSs) are prepared via melt compounding technique, and their structures, thermal stabilities, mechanical, rheological and electrical properties are reported. Scanning electron microscope and X-ray diffraction exhibit that graphene platelets of MEGONS are well dispersed and exfoliated in the PBT matrix even at high MEGONS content of 4.0 wt.%. DSC cooling and following heating thermograms of the nanocomposites demonstrate that graphene platelets of MEGONS play a role as effective nucleating agents for PBT a-phase crystals and thus lead to accelerating the overall crystallization of the nanocomposites. Thermal stability of PBT/MEGONS nanocomposites improved substantially due to the gas barrier effect of graphene platelets of MEGONS dispersed in the PBT matrix. The rheological analysis shows the low frequency plateau of shear modulus and the shear thinning behavior of the nanocomposites. The mechanical modulus of the nanocomposites enhanced significantly with increasing MEGONS content. The electrical conductivity test shows a pronounced increase in electrical conductivity from an insulator to almost a semiconductor with increasing MEGONS content. The electrical percolation threshold of the nanocomposites is found to be formed at the MEGONS concentration between 1.0 and 2.0 wt.%.