PROCESSING, STRUCTURE AND PROPERTIES OF POLYPHENYLENE SULPHIDE/GRAPHENE NANOPLATELETS FIBRES

Abstract

This study observed the processing, structure and properties of polyphenylene sulphide (PPS)/graphene nanoplatelet (GNPs) fibres. Three GNP types, namely GNP grades C300, C750 and M5 were used as reinforcements, to identify the best GNP to produce PPS/GNP nanocomposite fibres with the highest tensile modulus and stress at break. Masterbatches (MBs) (10 wt.%) were diluted to give compounds with various filler loadings (0.0, 0.5, 1.0, 2.0, 3.0, and 5.0 wt.%). They were prepared using a twin screw extruder equipped with gravimetric and volumetric feeders. PPS/GNP fibres were produced using a melt spinning machine from compounds produced at 300 °C using drawing speeds of 42, and 139 m/min. The effect of single and double twin-screw compounding during MBs preparation was also compared. Post-drawing was then done on the selected sample using two rollers at different temperatures and draw ratios. Results obtained from this study showed that the addition of GNP in PPS matrix increased complex viscosity, storage and loss modulus of the PPS/GNP masterbatches, for which the addition of GNP more than 2 wt.% resulted in the largest increase in these properties. Double extrusion increased the viscosity of the masterbatches with GNP C-grades by a factor of 2, but had little effect on the unfilled PPS and that with M5. The addition of GNP C300, C750 and M5 on PPS increased tensile modulus of the as-spun fibres. The fibres produced from double extruded masterbatches with GNP C300, C750 and M5 had higher degrees of crystallinity than that of fibres from single extruded masterbatches. The post drawing increased tensile modulus and stress at break, in which hot drawing (at temperatures above the Tg – 93 ℃) showed a better improvement in tensile modulus than cold drawing (at room temperature). The post drawing, however, decreased the strain at break. Analysis of the crystallisation – orientation – tensile properties relationship showed that the improvement of the tensile modulus and stress at break was more influenced by the orientation, indicated by the ratio of peak intensities of Raman spectra, while the strain at break was more affected by crystallinity. Finally, the experimental data were analysed using the Halpin – Tsai model and interpreted in terms of the filler aspect ratio, effective modulus and orientation.

Date of Award	29 Jul 2025
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Ian Kinloch (Main Supervisor) & Arthur Wilkinson (Co Supervisor)