Effect of poly(etherimide) chemical structures on the properties of epoxy/poly(etherimide) blends and their carbon fiber‐reinforced composites

Poly(etherimide)s (PEIs) with different chemical structures were synthesized and characterized, which were employed to toughen epoxy resins (EP/PEI) and carbon fiber-reinforced epoxy composites (CF/EP/PEI). Experimental results revealed that the introduction of the fluorinated groups and meta linkages could help to improve the melt processability of EP/PEI resins. The EP/PEI resins showed obviously improved mechanical properties including tensile strength of 89.2 MPa, elongation at break of 4.7% and flexural strength of 144.2 MPa, and good thermal properties including glass transition temperature (Tg) of 211°C and initial decomposition temperature (Td) of 366°C. Moreover, CF/EP/PEI-1 and CF/EP/PEI-4 composites showed significantly improved toughness with impact toughness of 13.8 and 15.5 J/cm2, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011