1. Fracture Toughness of PEI Modified Epoxy Resin CFRP Composites
- Author
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M. Takezawa, K. Ooishi, G. O. Shonaike, O. Watanabe, and A. Murakami
- Subjects
chemistry.chemical_classification ,Toughness ,Materials science ,Thermoplastic ,Polymers and Plastics ,Mechanical Engineering ,Delamination ,Composite number ,Izod impact strength test ,02 engineering and technology ,Epoxy ,021001 nanoscience & nanotechnology ,Polyetherimide ,chemistry.chemical_compound ,020303 mechanical engineering & transports ,Fracture toughness ,0203 mechanical engineering ,chemistry ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,Materials Chemistry ,Ceramics and Composites ,Composite material ,0210 nano-technology - Abstract
This paper describes the delamination toughness (GIC) of polyetherimide (PEI) modified epoxy resin reinforced with carbon fiber (CFRP). The epoxy resin was modified by using a thermoplastic PEI and cured with dicyanamine (Dicy). The modified resin was reinforced with cross-woven and uni-directional (UD) carbon fiber. The delamination toughness and impact tests were carried out by using a Double Cantilever Beam (DCB) testing procedure and Dynatup impact testing machine. GIC of PEI modified epoxy resin CFRP composite was about 2.5 times higher than the unreinforced PEI modified epoxy resin. However, GIc of cross-woven CFRP was higher than that of UD-CFRP. This was attributed to phase separation which occurred more easily in the cross-woven CFRP composite as a result of more space between the prepreg plies. The effect of PEI on impact energy is insignificant below 20 wt%. Thus the total energy absorbed was improved when the PEI content was 30 wt%. The impact damaged area as evaluated shows the damaged area of unmodified resin to be three times higher than the PEI modified CFRP composites. This indicates that the damage tolerance of the PEI modified CFRP was superior to that of the unmodified CFRP.
- Published
- 2000