Incorporation of Carbon Nanoparticles in Polyaryletherketone Matrices for High Performance Liquid Chromatography Applications

Abstract

Polyaryletherketone (PAEK) plastics are an option for rotary shear valves in High Performance Liquid Chromatography (HPLC) applications owing to their high strength, thermal resilience, and chemical inertness. In this study, the effects of adding carbon nano particles at a 1% weight loading to 30% carbon fiber loaded PAEK plastics via a simple melt blending process were explored and compared to neat PAEK blends. Experimental blends were tested for their Young’s modulus, relaxation under sustained load and temperature, yield strength, and internal defects. It was found that OH-functionalized graphene nano particles increased the moduli of PEEKCF30 and PEKEKKCF30 by 10.8% and 4.7% respectively. These results were considered statistically significant by hypothesis tests for a 95% confidence level. Further, a neat PEKKCF30 blend was determined to have a 30.2% increase from the neat PEEKCF30 blend and was also statistically significant. Under sustained load at ambient temperature, it was found that graphene oxide reduced the relaxation force by 10% in a PEEKCF30 blend and the neat PEKKCF30 blend reduced this force by 36% while both were statistically significant. Under sustained load at elevated temperatures, the PEKKCF30 blend performed well compared to neat PEEKCF30 at all temperatures with a detriment at 90C of only -1.2%, and improvements of 7.6% & 3.1% at 110C, & 130C respectively. Yield strength calculations revealed a 10% and 15% improvement for PEEKCF30 functionalized graphene and neat PEKKCF30 respectively. Finally, microscopic analysis revealed void formation and contaminants were more common in blends with carbon nano particles. From this screening analysis, the neat PEKKCF30 base polymer and OH-functionalized graphene additive are recommended for further exploration.