Exfoliated graphite as a filler to improve poly(phenylene sulfide) electrical conductivity and mechanical properties

Abstract

Electrical conductive poly(phenylene sulfide) (PPS)/exfoliated graphite (EG) composites were prepared by a 1-chlornaphthalene blending method, and the interface effects of EG and PPS on PPS/EG properties were characterized. EG was an excellent nanofiller for enhancing composite conductivity, and PPS/reduced exfoliated graphite oxide (REGO) composite displayed better conductivities in the range from 3.42 × 10⁻³ to 1.17 × 10⁻² S cm⁻¹ as REGO loading increased from 0.5 to 5 wt%. However, PPS/exfoliated graphite oxide (EGO) exhibits a much lower conductivity than composite reinforced with REGO. EGO can be well dispersed into PPS matrix, but the oxygen-containing carbons introduce structural defects on the EGO surface that disrupt the electronic continuum medium and reduce electrical conductivity. However, the incorporated EGO can effectively improve the mechanical properties of PPS, but REGO displays very poor capacity to enhance PPS mechanical performance. When EGO concentration reached 1 wt%, the breaking strength of PPS/EGO achieved the maximum 1.3 × 10³ MPa, and this value was 109.5 times that of PPS. The excellent mechanical properties of PPS/EGO were mainly attributed to the heterogeneous nucleation of EGO and the formation of a large number of covalent bonds by EG–thiol adducts.