Study On Bonding Mechanism Of Basalt Fiber Reinforced Polymer

Fiber reinforced polymer has very good properties and also often been used in construction field. Glass fiber and carbon fiber are usually been used as reinforced materials. Basalt fiber (BF) has excellent mechanical properties and chemical stability, and is an environmentally friendly fiber. Therefore, the use of basalt fiber reinforced polymer as reinforced materials has important application value for construction field. In this paper, the main research contents are as follows:(1) Through using X-ray photoelectron spectroscopy analysis of basalt fiber treated with different concentrations of the silicon coupling agent, we can select a suitable concentration of silane coupling agent to deal with the basalt fiber. (2) Comparative study of the mechanical properties, fracture morphology and composite materials, functional groups of the basalt fiber reinforced polymer (epoxy resin and phenolic resin) composite interface change of two groups of basalt fiber reinforced polymer treated with two kinds of coupling agent concentration:0.8wt% and 1.0wt%. The conclusions are as following:(1) From the XPS and FTIR analysis results, a new chemical bond formed on the fiber surface after the coupling agent treatment, which is Si-O-Si bond. In setting the experimental conditions, when the concentration was 0.8wt%, the fiber has the lowest O/C ratio, the largest Si-O-Si bond area ratio and the lowest amount of carbon dioxide, indicating that at this time the largest amount of KH-550 had been adsorpted to the fiber surface. When the concentration of KH-550 increased, the adsorption amounts of coupling agent began to decrease. It can be concluded that BF should be treated with coupling agent of the concentration between 0.8wt% and 1.2wt% to achieve the best results.(2) The mechanical properties comparison between 0.8wt% and 1.0wt% group of basalt fiber reinforced epoxy resin showed that 1.Owt% group has a better shear strength, and its scanned image showed that B group composite material had more resin attached to its fiber surface. FTIR test had determined the formation of a new chemical bond C-OR on the composite interface, According to the test in the observed FTIR absorption peak type, between the fiber and resin, the C-OR bond should be C-O-NH and C-O-Si bond, that is, epoxy resin and fiber fracture surface of the formation of C-O-NH-amino key; resin and fiber surface hydroxyl silanol formed C-O-Si bond. XPS test confirmed that the 1.0wt% group had more C-OR bond on the composite interface than 0.8wt% group, and it has a better mechanical performance. A good combination between the epoxy resin and BF is attributed to the formation of two chemical bonds. Thereby only increase the number of chemical bonds formed between epoxy and BF, the quality of BFR-Epoxy will be improved.(3) The mechanical properties comparison between 0.8wt% and 1.0wt% group of basalt fiber reinforced phenolic resin showed that 0.8wt% group has better shear strength. FTIR test had determined the formation of the new chemical bonds may be C-N-C, C-O-Si:formation of C-N-C bond between phenol and amino on the composite interface, and formation of C-O-Si bond between phenol and silanol. XPS tests confirmed the 0.8wt% group formed more C-O-Si bonds, which made it has better composite interface.