Fracture Toughness of Carbon Fiber Reinforced Composites with Rubber Modification

Abstract

Fracture toughness and the possibility of recycling for Carbon Fiber Reinforced Plastics (CFRP) under mode one and mode two loadings are examined. Epoxy matrix is modified by CNBR rubber particle which diameter is smaller than 100 nano meter. Three kinds of rubber content (5,10,15%) are used. Two types of test methods whose modes are different are conducted. After the specimen fracture, recycled specimens are made by adhesion. Fracture toughness is measured at the tests. Fracture surface is also observed by SEM. As a result, following conclusions are obtained. When the interlaminar fracture test using recycled CFRP specimen is conducted under Mode one loading, fracture toughness is improved using rubber modified matrix. For recycled CFRP specimen under mode two loading, fracture toughness of CFRP using unmodified epoxy is improved. In this case, fracture toughness for modified CFRP is improved but it is not as high as than CFRP with unmodified recycle CFRP. From SEM ovservation on fracture sufface under mode two loading, there is a difference on fracture surfaces. Specimen whose fracture toughness is high has a ductile properties.