Interfacial shear strength (IFSS) of poly(arylene ether phosphine oxide) (PEPO) coated carbon fibers was evaluated via microdroplet tests and compared with results obtained from carbon fibers coated with poly(arylene ether sulfone) (PES), Udel® P-1700 and Ultem® 1000. Interfacial adhesion between thermoplastics and uncoated carbon fibers was also measured in order to understand the adhesion mechanism. PEPO coated carbon fibers showed the highest IFSS, followed by PES, Udel and VItem coated fibers. A similar trend was observed for thermoplastic/uncoated fibers. SEM analysis indicated that only PEPO coated fiber exhibited cohesive failure in the vinylester resin, while others showed failure at or near the interface of polymer coating and vinylester resin. The enhanced interfacial adhesion by PEPO coating could be attributed to the strong interaction of P = 0 moiety to the fiber as well as to the vinylester resin.

Interfacial shear strength (IFSS) of poly(arylene ether phosphine oxide) (PEPO) coated carbon fibers was evaluated via microdroplet tests and compared with results obtained from carbon fibers coated with poly(arylene ether sulfone) (PES), Udel® P-1700 and Ultem® 1000. Interfacial adhesion between thermoplastics and uncoated carbon fibers was also measured in order to understand the adhesion mechanism. PEPO coated carbon fibers showed the highest IFSS, followed by PES, Udel and VItem coated fibers. A similar trend was observed for thermoplastic/uncoated fibers. SEM analysis indicated that only PEPO coated fiber exhibited cohesive failure in the vinylester resin, while others showed failure at or near the interface of polymer coating and vinylester resin. The enhanced interfacial adhesion by PEPO coating could be attributed to the strong interaction of P = 0 moiety to the fiber as well as to the vinylester resin.