Recycling Process And Degradation Mechanism Of CF/EP Composites Under Supercritical N-Butanol

Carbon fiber reinforced polymer (CFRP) with a series of good performances, such as high strength, high impact resistance, corrosion resistance and thermal stability, is widely used in many fields. So the amount of the wasted CFRP is increasing rapidly as the using. The wasted CFRP contains carbon fiber with high value. In order to recycle and reuse the resources, and resolve the problem of environment pollution, the work of recycle and reuse the wasted CFRP receives more and more attention.Homemade CF/EP composites are recycled by the supercritical fluid reaction equipment. The main research about recycling process and mechanism is as follows:(1) The degradation of CF/EP composites under supercritical butanol with non-additive and alkalic additive is studied. The results showed the degradation can be accelerated by increasing the holding temperature; extending holding time can only increase the depth of degradation; the alkalic additive can obviously accelerate the degradation, and there is a positive correlation between the concentration of additive and the degradation rate of resin; the content of butanol and the weight of CF/EP composites have little impact on the degradation. The single fiber tensile strength of recycled carbon fiber showed that increasing the holding temperature and the additive concentration can decrease the mechanical properties of recycled carbon fiber.(2) The optimum process of CF/EP composites degradation under supercritical butanol was explored. The result shows the optimum process is holding temperature at 330℃, holding time at 60min, KOH concentration at 0.0538mol/L, feed ratio at 0.024 g/mL.(3) The non-catalytic and catalytic degradation products of CF/EP composites were studied. The supercritical butanol can provided H·to the degradation process through the guerbet reaction. The alkalic additive (KOH) can promote the reaction of aldol condensation to increase the hydrogen donor capability of supercritical n-butanol; and the alkalic additive promoted the second reaction of the degradation products. According to the solid phase and liquid phase products, the non-catalytic and catalytic degradation mechanisms of CF/EP composites were concluded.