Study On Unsaturated Polyester Composites Reinforced By Modified Cellulose Fibers

Fiber reinforced plastics(FRP)is a kind of composite material with unsaturated polyester(UPR)as matrix and glass fiber as reinforcement.It has been widely used in aviation,railway,construction and other fields because of its high strength and good processability.However,due to the non-degraD-Ability of glass fiber,a large number of FRP wastes have not been effectively disposed,which not only caused the waste of resources,but also caused a series of environmental issues.Therefore,it is proposed that the UPR be reinforced with degraD-Able cellulose fiber(CF)instead of glass fiber.CF is a natural material that can be degraded and has excellent mechanical properties.Filling UPR with CF can effectively solve the problem of reprocessing of waste FRP from the original source.In this research,the CF was modified by furan compound.The Diels-Alder reaction between the modified CF and the unsaturated double bond in the UPR matrix was carried out,so the interfacial adhesion between the fiber and the UPR was enhanced by chemical bond.Due to the thermol reversibility of D-A reaction,the composites exhibit repeatable thermoplasticity.Based on the above ideas,the following research was carried out in this paper:the activity of the D-A reaction between the modified cellulose fiber and the unsaturated polyester was investigated,and the results showed that the D-A reaction took place between the furan ring modified cellulose fiber and the unsaturated polyester,and the r-D-A reaction temperature was about 130?;the mechanical strength of the composite was explored,and the results showed that the modified fiber could obviously improve the impact and bending strength of the composite;The interface morphology of the fracture surface was investigated by scanning electron microscope,and the results showed that the modified fiber had a closer bonding interface with the polyester matrix;in addition,the reproducibility investigation of the composites showed that the composite material could be two times hot pressed at 140?.