Studies On The Interface Optimization Of Carbon Fiber Fabric Reinforced Vinyl Resin Composites

At present,carbon fiber reinforced resin matrix composites with excellent mechanical properties are widely used in aerospace,sports,transportation and other fields.In recent years,under the requirements of low cost,high performance,automation and integration of materials in the Marine industry,resin based carbon fiber reinforced composites are used more and more in the field of Marine engineering.Based on the Marine environment features,used in the Marine environment of the composite material has good corrosion resistance,the use of highly corrosion resistant vinyl ester resin combination with carbon fibre is a feasible way,but the commercialization of carbon fiber and vinyl resin interface adhesion strength is insufficient,the problem of low shear strength and restrict its application in the field of ship.In view of this,this paper focuses on the interface modification of carbon fiber reinforced vinyl resin composites,and explores the applicability of modified composites in complex Marine environment.The purpose of this project is to improve the interface bond between carbon fiber fabric and vinyl resin by surface modification,and to improve the application feasibility of composite materials in complex Marine environment.The main work and results of this topic are as follows:(1)The carbon fibers were sizing with different sizing agents,and the surface elements and functional groups of the carbon fibers were analyzed by X-ray photoelectron spectroscopy.The test results show that compared with the existing products in the market,the carbon fiber surface with the new type A size agent accounts for A large proportion of O and N elements,and the content of oxygen-containing functional groups is high,corresponding to the high interface strength of the composite material.The interlayer shear strength rises to 30.5 MPa,and the performance is increased by 25%.(2)Two kinds of coupling agents were used to modify the carbon fiber fabric,and the modification effect was preliminarily tested by testing the interlaminar shear strength of the composite.The results show that the silane coupling agent can improve the properties of the composites by less than 5%,and the increase is small,while the macromolecular coupling agent can effectively improve the interface strength of the composites.The further study of macromolecular coupling agent showed that the modification effect of macromolecular coupling agent was better than that of spraying(spraying fabric process).The interlayer shear strength of T700 grade and T300 grade carbon fiber composites modified by macromolecular coupling agent increased by 41.4% and 35.1%,respectively.The water resistance test showed that the property retention rate of the composite was above 85%.(3)The optimal conditions of plasma treatment of carbon fiber fabric were determined by orthogonal experiment,and the surface morphology and structure composition of carbon fiber before and after treatment were detected and analyzed by means of SEM and XPS.The surface of carbon fiber was etched by plasma treatment,and the surface roughness and specific surface area of fiber were increased.At the same time,O and N elements in the air are introduced into the fiber surface,and the content of O and N elements on the surface of carbon fiber increases,and the content of oxygen-containing functional groups increases.The interlamellar shear strength of T700 grade and T300 grade carbon fiber composites modified by plasma treatment reached 29.4 MPa and 45.7 MPa,respectively,which increased by 21.3%and 30.6% compared with that without plasma treatment.(4)Try to use the two methods to modify carbon fiber together.By comparing the properties of composite materials,it is found that the modified effect is not the expected double superposition,but similar to the effect of a single method.Although the two modification methods can further improve the interface properties of the composite,the improvement effect is not obvious,and the modification effect is limited by the quality of carbon fiber.(5)The test results of accelerated aging in artificial environment show that compared with the unmodified carbon fiber composite modified by macromolecular coupling agent,the performance of carbon fiber composite modified by boiling water,UV irradiation,alternating wet heat and other accelerated tests has been significantly improved,and the performance retention rate is more than 80%,showing excellent Marine environmental resistance.It facilitates the use of carbon fiber reinforced vinyl resin composites in Marine environments.