Effect of Ultraviolet Irradiation on Properties of Novel Model BMI Matrix Composites

T700 carbon fiber reinforced BMI composites(T700/5429) were irradiated for 90 days by using the ultraviolet lamp.Scanning electronic microscope,universal testing machine,FTIR and DMA were used to analyze the changes of surface morphology,flexural fracture morphology,the transmission peak area of characteristic groups and mechanical properties of the composites before and after ultraviolet irradiation.The results indicated that after ultraviolet irradiation for 90 days,carbon fibers on the surface of T700/5429 exposed and the resin matrix was detached.On the other hand,in-plane compressive strength and bending strength of the composites were almost intact.The changes of transmission peak area,the exposure of fibers and the decrease of glass transition temperature indicated the imide ring of the resin matrix was dissociated after ultraviolet irradiation for 90 days.