| BF has great properties, and BFRP has been widely used in many areas. The interphase of BFRP is an important microstructure, whose composition, performance, and the combined mode and strength have a significant impact on the mechanical properties of BFRP. The following is what the thesis mainly about:(1) applying Orthogonal test to research optimum technics parameters of Epoxy-BFRP, including temperature, time and Silane coupling agents; (2) Study macroscopic mechanical properties, fracture morphology and Functional groups on BF surfaces of Epoxy-BFRP, and analysize the effects of silane coupling agents on mechanical properties of composites and the reasons for performance differences and interface mechanism.Conclusions are as follows:(1) for the mechanical properties of Epoxy-BFRP, influence size of technics paraters is coupling agents≥temperature≥time. Under the molding pressure 1.8MPa, the optimum technics are molding temperature 40℃, gluing time 2h, and coupling agent KH550; (2) the Si on the surfaces of BF treated with KH550, KH560 and KH570 and the Si of silane couping agents react to form Si-O-Si, the order of the amouts of Si-O-Si of the three coupling agents and BF is KH550≥KH570≥KH560; (3) the treatment of BF with KH550, KH560 and KH570 can improve the interface bonding properties of Epoxy-BFRP, the order of which is KH550≥KH560≥KH570. The end of the three silane coupling agents and the BF surfaces react to form the same Si-O-Si, while the bonding modes of the other end and Epoxy are different, both of KH550 and KH560 combined Epoxy with chemical bonding, while the interface of KH550 and Epoxy is IDIPN; (4) the interface between epoxy and the BF treated with all the three silane coupling agents is closely combined, and the interface do not debond when specimen damages, the main damage occur in the matrix, the mechanical properties of the interface is better than that of matrix; (5) after water bathing, all the interface properties of CONTROL-Epoxy-BFRP, KH550-Epoxy-BFRP and KH560-Epoxy-BFRP decrease similarly, but that of KH570-Epoxy-BFRP decrease relatively less, partly because the bonding modes of KH550/Epoxy and KH560/Epoxy differ from that of KH570/Epoxy; (6) after water bathing, BF surfaces has a small amount of resin, and most of the surfaces is smooth. The facture surfaces are flat, interface between fiber and matrix debonds, some fibers are pulled out from the matrix and holes left in the matrix. The Failure mode is a brittle fracture. |
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