Glass fiber reinforced plastic (FRP,commonly known as the “fiberglass”) is a kind of glass fiber for “bones”, with unsaturated polyester, epoxy resin and phenolic resin as the “muscle” after the composite process, a novel functional material produced, as a kind of composite material. Because of fiberglass pultruded profiles unique advantages, they have been widely used in aerospace, railway, ship, building decoration, home furniture, building materials sanitary and environmental sanitation engineering, etc..
2, Analysis of the adhesive
How to improve the fiberglass pultruded profiles “bones”, “muscle” between the adhesive, keep them in a more intimate relationship? We know that the resin by chemical groups containing two categories containing polar groups and containing polar groups. The resin containing polar groups (such as epoxy resin, polyester resin and phenolic resin) and bonding glass fiber by polar groups and the surface of the glass fiber in the molecular chain of M-OH (M Si, Fe, Al) the formation of the chemical bond, hydrogen bond and other physical effects are.
Little M-OH resin reaction and structure formation of chemical bonds, so the number of chemical bonds formed a firm is not much. The resin not containing polar groups (such as polyethylene and hydrocarbon) interface bonding of glass fiber is to rely on the Fan Dehua force (i.e. molecular interactions) or copolymerization etc..
3, Coupling agent
But the effect of pure resin and glass fiber is relatively weak, we should improve the coupling agent adhesion between glass fiber and resin.
For thermosetting resin, silane coupling agent function is very significant. According to the chemical bond theory, the chemical bond formed between the silane coupling agent containing organic groups and the resin matrix to improve the properties of composite materials. So the choice of coupling agent, to consider coupling agent and a resin containing reactive groups. For the thermosetting resin which doesn’t contain polar groups and reactive groups, the coupling agent function is not significant.
Glass fiber surface treatment should be done before production. Otherwise, fiberglass pultruded profiles production can easily lead to delamination. On the surface of glass fiber, are generally treated with coupling agent. The coupling agent can not only improve the interfacial adhesion of composites, and the effect of wet conditions in electrical and mechanical properties were significantly.