The rapid development of electronic and electrical, materials and composite materials, the epoxy resin is from the general products to high functional and high value-added products direction; however, although the epoxy resin epoxy resin has good comprehensive advantages, but also has a fatal weakness "brittle". With the rapid development of the application, the research on the mechanism of toughening is becoming more and more intensive. The research on the mechanism of toughening provides a theoretical basis for finding new toughening methods. According to experts, the island structure toughening is one of them, toughening epoxy resin curing homogeneous system into 1 multiphase system. The "island structure" belongs to this system, that is, the toughening agent integrates the spherical particles into the dispersed phase in the continuous phase of the epoxy resin crosslinking network."Island structure" is a kind of toughening agent, which is made up of spherical particles which are dispersed in the continuous phase of epoxy resin crosslinking network. When the island structure is formed, the cracking resistance of the material will be changed, that is to say, the fracture toughness of the material is greatly improved, and the mechanical properties and heat resistance of the material are smaller. In the past, the study on the toughening mechanism is focused on the effect of the rubber particles or the plastic with excellent performance on the toughening of epoxy resin. In fact, epoxy resin, the average chain of rubber toughening Gen has important influence. Chinese Epoxy Resin Industry Association experts said, when the "island structure" in the dispersed phase particles is low modulus elastomer, its main role is to induce epoxy resin matrix yielding and plastic deformation, and thus greatly improve the fracture toughness. Without the existence of "island structure", it is impossible to exert the potential of energy consumption. Of course, the deformation and tearing of rubber particles contribute to the toughness, but only in the high degree of crosslinking of the resin is not easy to deform when the dominant position.

China Epoxy Resin Industry Association experts said, "island structure" toughening is one of them, toughening is the epoxy resin curing homogeneous system into 1 multiphase system. The experiment was carried out on CTBN in the cured epoxy resin in the form of "island structure" and not on the toughening effect, found where the foot can form "island structure", the fracture toughness multiplies, temperature drop is small; if cannot form "island structure", even the CTBN of the system also. Only plays the role of increasing flexibility, can not be described as toughening agent. Based on the above understanding, the development of a suitable for epoxy / anhydride system "island" type epoxy resin toughening agent, and built an annual output of 100 tons of production workshop. It is a different activity terminated by ester bonds or amine ester bond mixture chain linked polymer of different kinds, the modified epoxy / anhydride system of the fundamental reason is that it can dissolve the resin curing, the curing process and it can form a suitable particle separation the "island structure".