Preparation Of Carbon Fiber Special Epoxy Structural Adhesive

As a new material,carbon fiber has the advantages of high strength,high modulus of elasticity,high electrical conductivity and thermal conductivity,high temperature resistance and biocompatibility.It has been widely used in national defense industry and daily life.In addition to integral molding,other traditional connection methods,such as bolt connection and riveting,all focus the stress on one point in the connection process,which will cause great damage to the material structure if it exists for a long time.Epoxy structural adhesive has high bonding strength because it can form a network structure with high crosslinking degree after curing.It can make the material stress uniform when bonding the material,greatly reduce the stress concentration caused by the traditional methods such as bolt connection,riveting.It can make the durability of the components more excellent,better stability,thus ensuring the integrity of the components.Because of its simple construction process,the working efficiency of the factory will also be improved.Therefore,people pay more and more attention to using epoxy structural adhesive to connect carbon fiber materials.In this paper,two kinds of epoxy structure adhesive were designed,which were one-component epoxy structure adhesive and two-component epoxy structure adhesive.Two-component epoxy structure adhesive were divided into two kinds,which were two-component epoxy structure adhesive with oligomide as curing agent and two-component epoxy structure adhesive with polymercaptan as curing agent.One-component epoxy structural adhesive selection is organic acid hydrazide do curing agent is suitable for high temperature curing,curing at 150?,the bonding strength can reach 41N/mm~2.The shear strength of the Loctite EA 9432 NA was 39 N/mm~2,and the shear strength of the two-component epoxy adhesive was higher than that of the Loctite EA 9432 NA.To make low polyamide curing agent preparation of two-component epoxy structural adhesive is room temperature curing,generally is 25?for 24 h curing,curing time is to gradually reduce the increase of temperature,curing strength can reach 40 N/mm~2.The shear strength of the Loctite EA E-120 HP was 30 N/mm~2,and the shear strength of the two-component epoxy adhesive was higher than that of the Loctite EA E-120 HP.When low molecular polyamide is used as curing agent,the time is too long,and the single component epoxy structural adhesive needs to be cured at high temperature,which greatly limits the service conditions.The third epoxy structural adhesive designed uses polythiols as curing agent,and the gel effect can be achieved within 5 min and fully cured within 6 h,greatly reducing the time.After curing,the strength can reach 15 N/mm~2,which can play a good role in preliminary fixation of carbon fiber parts and facilitate further processing.These three kinds of epoxy structural adhesives have good adhesion to other materials besides carbon fiber.The one-component epoxy structural adhesive has good adhesion to stainless steel,aluminum sheet and other metals by testing different materials.The two-component epoxy adhesive with low molecular polyamide as curing agent has good adhesion to stainless steel,aluminum sheet and nylon 66 by testing different materials.The two-component epoxy adhesive with polymercaptan as curing agent has good adhesion to stainless steel,wood,PVC and glass.