Nonisothermal crystallization kinetics, morphology, and tensile properties of polyphenylene sulfide/functionalized graphite nanoplatelets composites

Polyphenylene sulfide (PPS)/graphite nanoplates (GNPs) nanocomposites were manufactured by simple melt compounding. The GNPs were first functionalized using synthesized benzimidazolium salt to improve the compatibility with PPS matrix. The functionalized GNPs showed an exfoliated dispersion in PPS matrix, which also could significantly improve the tensile properties of composites. Differential scanning calorimetry was used to investigate the nonisothermal crystallization kinetics of PPS/functionalized GNPs composites. The results showed that the PPS/functionalized GNPs composites always had a higher crystallization peak temperature (Tc) than pure PPS resin at different cooling rates due to the addition of GNPs. The GNPs could also play the role of heterogeneous nucleating agents to accelerate the crystallization; however, at high content, they could also limit the mobility of PPS macromolecular chains and hinder the crystallization. The Mo equation could be used to analyze the nonisothermal crystallization kinetics, whereas the Ozawa equation was not suitable for the nonisothermal crystallization process. Consistent with a previous analysis, the results also showed that the addition of GNPs could also decrease the crystallization activation energy (Ec) of PPS resin at low content while increasing the Ec at high content