A kind of method of sol-gel method modified benzoxazine resin/epoxy resin copolymer

Abstract

The invention provides a method used for modifying a benzoxazine resin / epoxy resin copolymer via sol-gel method. The method comprises following steps: 1, siloxane-modified glycidyl ether epoxy resin, benzoxazine resin, and silicon dioxide precursor are mixed, and are dissolved in acetone, and an obtained mixture is heated to 50 DEG C; 2, an acetic acid aqueous with a pH value ranging from 3 to 4 is added, wherein the adding amount of the acetic acid aqueous accounts for 4 to 6% of the total mass amount of the reagents in step 1; and 3, after 3h of reaction, water and acetone are removed via pressure reduction so as to obtain the modified benzoxazine resin / epoxy resin copolymer. According to the method, chemical method is adopted, so that flexible silicon oxygen bonds are introduced into the benzoxazine resin / epoxy resin copolymer network successfully, toughness and thermal stability are both increased obviously because of introduction of silicon oxygen bonds, and performance advantages of the two resins in the matrix are achieved as far as possible.

Description

technical field [0001] The invention belongs to the field of preparation of organic polymer compounds, and in particular relates to a method for modifying a benzoxazine resin / epoxy resin copolymer by a sol-gel method. Background technique [0002] In recent years, the demand for composite materials in the aerospace field has been increasing, and due to the special conditions of use, more stringent requirements have been put forward for their performance. Compared with ordinary composite materials, composite materials based on aerospace applications must not only meet the basic mechanical performance requirements, but also have good high temperature resistance. The heat resistance of composite materials largely depends on the structure of the matrix resin and the formulation of the curing system. [0003] As a new type of thermosetting resin, benzoxazine resin has attracted more and more attention because of its excellent performance and flexibility in molecular design. Ben...

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Problems solved by technology

[0007] Although the traditional benzoxazine resin / epoxy resin co-curing system improves the toughness of the benzoxazine resin to a certain extent, and the thermal stability of the mixture is higher than that of the corresponding epoxy resin cured product, however, simple co-curing Mixed curing is only a compromise between the advantages of the two resins. The thermal stability of the blended system is lower than that of pure benzoxazine resin, and its toughness is not as good as that of pure epoxy resin. It does not maximize the advantages of the two resins.

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