Study On Preparation And Properties Of Hybrid Fiber Reinforced Epoxy Composites

Hybrid fiber reinforced epoxy resin composite is a new composite material with high tensile strength,high flexural strength and good mechanical strength.It has become a research hotspot in the direction of composite materials.Carbon fibers and glass fibers are the two most widely used fibers for reinforcing epoxy resins.Carbon fibers have high Young’s modulus,low density,low thermal expansion coefficient,and good corrosion resistance.On the other hand,although the glass fiber has worse parameters than carbon fiber,its ductility is better.By using carbon fibers and glass fibers in a volume ratio of 1:1 to reinforce the epoxy resin with different hybrid structures,composite materials with different properties can be prepared to be applied in different environments.The mixture of carbon fiber and glass fiber in different structures will reduce the production cost of composite materials to some extent,and further expand the application range of hybrid fiber reinforced epoxy resin matrix composites.In this paper,the toughening effect of PVB on epoxy resin was explored by adding polyvinyl butyral（PVB）and chlorinated paraffin（CP）systems to epoxy resin matrix to improve the brittleness of composite materials and determine the amount of PVB added is 3%of the resin matrix mass fraction.The addition of CP is mainly to improve the flame retardant properties of the resin matrix,so that the application of the composite material is more extensive.After comparing the performance of different parts,the final addition of CP is 10%of the resin matrix mass fraction.A universal testing machine was used to test the mechanical properties of the composites.The microstructure of the composites was characterized by scanning electron microscopy（SEM）.Based on the modified parameters of epoxy resin,hybrid fiber reinforced epoxy composites with different hybrid structures were prepared by the pultrusion process.The volume ratio of carbon fiber to glass fiber in hybrid composites is 1:1.Through testing the mechanical properties of the composites,the effects of 7 kinds of hybrid structures,such as concentric,intra-layer,and interlayer,on the properties of the composites were investigated.Tensile,bending and shear results show that the tensile strengths of the seven structures are not significantly different and are basically between the tensile strength of carbon fiber reinforced epoxy resin composites and glass fiber reinforced epoxy resin composites;the interlayer hybrid structure,a layer of carbon fiber and a layer of glass fiber,has the highest bending strength;the intra-layer structure has a higher shear strength.At the same time,the composite materials were subjected to immersion experiments in different chemical media and the water absorption of the composites was measured.The results showed that the distilled water and NaCl aqueous solutions have similar hygroscopic characteristics.In the H₂SO₄ aqueous solution,the water absorption rate first increases.Afterwards,the balance decreases to the final equilibrium.Due to the corrosive effect of NaOH aqueous solution on the epoxy resin,the hygroscopic characteristics of the composite material have changed greatly.The parameters measured in the laboratory were used for the pilot test of the continuous fiber reinforced resin-based anchor production line of Shangqiu Guolong new material company of Henan Energy Chemical Group,and the products were sent to professional organizations for testing,test results were in line with national standards.The product has been awarded the"mine product safety mark certificate"issued by the national standard for safety of mining products.