Influences of exfoliated graphite on structures, thermal stability, mechanical modulus, and electrical resistivity of poly(butylene terephthalate)

Abstract

We report structural features and multifunctional properties of nanocomposites based on poly(butylene terephthalate) (PBT) and exfoliated graphite (EG), which are manufactured by melt-compounding technique. Scanning electron microscope and X-ray diffraction data exhibit that graphene platelets of EG are well dispersed and exfoliated in the PBT matrix even at high EG content of 7.0 wt %. Raman spectra support that graphene platelets of EG are interacted specifically with phenyl rings of PBT chains at nanocomposite interfaces. DSC cooling and following heating thermograms of the nanocomposites demonstrate that graphene platelets of EG 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/EG nanocomposites is improved substantially due to the gas barrier effect of graphene platelets of EG dispersed in the PBT matrix, especially at the active oxygen gas condition. Dynamic mechanical modulus of the nanocomposites is also enhanced significantly with increasing the EG content. The electrical volume resistivity of the nanocomposites is decreased dramatically from $ 10 18 to $ 10 6 X cm by forming the electrical conduction path at a certain EG content between 3 and 5 wt %. V C 2012 Wiley Periodicals, Inc. J Appl Polym Sci 125: E532-E540, 2012

Process–structure–property relationships in poly(butylene terephthalate) nanocomposites

“…In addition, the surface roughness of PBT/ nanosilica nanocomposites was higher than that of PBT. Li and Jeong (2012) used a melt compounding technique to prepare PBT/EG nanocomposites. The PBT/silica nanocomposites exhibited higher electromagnetic reflection compared to pure PBT.…”

“…As PBT is an intrinsically insulating material, electrical resistivity of PBT must be reduced in advanced applications that require electrostatic and/or electromagnetic dissipation (Li and Jeong, 2012). As PBT is an intrinsically insulating material, electrical resistivity of PBT must be reduced in advanced applications that require electrostatic and/or electromagnetic dissipation (Li and Jeong, 2012).…”

“…Li and Jeong (2012) studied the effects of EG on PBT electrical properties. The electrical volume resistivity of the PBT nanocomposites was dramatically decreased from approximately 10 18 to 10 6 Ω cm by forming an electrical conduction path with EG contents between 3 and 5 wt% (Li and Jeong, 2012). The electrical volume resistivity of the PBT nanocomposites was dramatically decreased from approximately 10 18 to 10 6 Ω cm by forming an electrical conduction path with EG contents between 3 and 5 wt% (Li and Jeong, 2012).…”

“…The electrical volume resistivity of neat PBT films was measured to be approximately 10 18 Ω cm. It is notable that nanocomposites with electrical resistivity of approximately 10 6 Ω cm can be used for thermoplastic applications that require electrostatic dissipation and partial electromagnetic insulation (Li and Jeong, 2012). This substantial reduction in the electrical resistivity is associated with the formation of an electrical conduction path (via the electron hopping mechanism).…”

Electrical, Thermal, and Morphological Properties of Poly(ethylene terephthalate)-Graphite Nanoplatelets Nanocomposites

“…Typically, high ultrasonication process will be used for breaking down the GNP to smaller sheets. Both GIC and GNP are commonly modified graphite forms that have been used for preparing polymer-carbon composites [1][2][3][4].…”