POLYPHENYLENE SULFIDE NANOCOMPOSITES TO ENABLE HIGH-RATE THERMOPLASTIC COMPOSITE MANUFACTURING

When designing next generation, fuel efficient aircraft, weight must be minimized and manufacturing efficiency must improve, justifying the adoption of thermoplastic composites (TPCs). Among these materials, polyphenylene sulfide (PPS) offers a solution to achieve low weight, high throughput TPCs due to rapid cycle times and the ability to be joined through fusion bonding. Induction welding is a fusion bonding technique that employs electromagnetic fields to induce heating within CFRP laminates through interactions with electrically conductive domains (i.e. the carbon fiber). This process is limited by the insulating nature of the PPS surrounding the carbon fiber, therefore requiring slower weld speeds and wasted energy. Here, we examine a potential method for improving the efficacy of induction welding – increasing the electrical conductivity of the PPS matrix through the addition of multi-wall carbon nanotubes (MWCNT). Results indicate that CNTs improve the electrical conductivity of neat PPS by 12 orders of magnitude, while increasing the zero shear viscosity by 3 orders of magnitude. The addition of MWCNT shifted the onset of crystallization of PPS to higher temperatures indicating faster nucleation, with no apparent change in the crystalline structure.