Copolymer Networks from Carboxyl-Containing Polyaryletherketone and Diglycidyl Ether of Bisphenol-A: Preparation and Properties

This article presents a new type of epoxy-toughening system, in which high-T(g) polyaryletherketone (PEK-L) containing one carboxyl group per repeating unit was utilized to randomly copolymerize with epoxy resin (DGEBA) to form crosslinking network. Compared to the neat epoxy resin, the PEK-L/DGEBA copolymers showed simultaneous enhancement in flexural strains at break by 282%, G(IC) value by 193%, and flexural strength by 14%. The reason was attributed to the uniform three-dimensional copolymer network interweaved by PEK-L and DGEBA segments through strong covalent bonds. The copolymerization process were monitored and examined by FTIR spectra. The effect of copolymer composition on the thermal and mechanical properties as well as toughening mechanism were also investigated and discussed in detail. VC 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 2424-2431, 2010