Surface-Modified Carbon Fiber on Strength of CFRP and Curing Behavior of Matrix Resin

There is a method, named photo-oxygenation, of surface modification treatment, which utilizes a synergist effect of ultra-violet rays and ozone. A functional group involving oxygen is induced on surface of carbon fiber. Wettability to water, phenolic and epoxy resin of carbon fiber surfacemodified by photo-oxygenation can be improved. Mechanical properties of CFRP and CFRC made of surface-modified carbon fiber are remarkably better than those of them made of carbon fiber asreceived. Properties of CFRP made of epoxy resin change in color and dynamic visco-elastic property. In this report, we study the influence of the functional group on curing behavior of epoxy resin and mechanical properties. The results are as follows.(1) Apparent activation energy of epoxy resin in curing is proportional to O/C value (the ratio of oxygen to carbon content).(2) Strength of CFRP is able to be changed by controlling O/C value.