Surface sizing agent for aramid fiber composite material as well as preparation and application of surface sizing agent

Abstract

The invention relates to a surface sizing agent for an aramid fiber composite material as well as preparation and application of the surface sizing agent. The preparation method comprises the following steps of firstly, preparing a solution containing a polyphthaloyl chlorobenzene diamine oligomer from diamine and diacyl chloride as main raw materials; and adding a silane coupling agent to carry out oligomer modification to prepare a copolymer solution of an oligomer terminated by the coupling agent, namely the surface sizing agent for the aramid fiber composite material. In the prepared surface sizing agent for the aramid fiber composite material, the mass content of the copolymer of the oligomer terminated by the coupling agent is 1-10%; the surface of aramid fiber of the aramid fiber composite material is coated with the surface sizing agent, then drying is performed to remove a solvent NMP, and hydrolyzing is performed in air to obtain an aramid fiber reinforcement; the low-molecular oligomer similar to the aramid fiber in structure is contained, polar groups such as -NH-CO-,-COOH and -NH2 are contained, hydrogen bonds can be formed, meanwhile, the silane coupling agent is introduced to react with the oligomer to prepare Si-OH beneficial to epoxy resin reaction, and the bonding performance between the aramid fiber and resin is improved.

Description

Technical field [0001] The present invention belongs to the technical field of composite materials, and the surface of a aramid fiber composite material and its preparation and application thereof. Background technique [0002] Aramid fiber composites have excellent performance such as high strength, high modulus, high temperature resistance, and alkali resistance, widely used in aerospace, defense military, electronic equipment and other fields. For composites, the interface binding performance between fibers and resins is the most critical. However, the aramid fibers have a large amount of benzene ring on the backbone, and the axial directional degree is high, the bitmap effect of the benzene ring also limits the amide group and other groups, and therefore, the aramid fiber and the resin matrix are present between the resin matrix The interface binding is poor, and the problem of small shear strength is small. The effective method of solving this problem is to surface modificat...

AI Technical Summary

Problems solved by technology

However, physical modification requires higher equipment, has a greater impact on the environment, and has poor storage effect, which is not conducive to industrial production.

[0003] The prior art discloses a method for modifying aramid fiber with a silane coupling agent, specifically using gamma-ray high-energy radiation to treat the aramid fiber, and then using dichlorobutane and NaOH on the surface of the fiber for chlorinated grafting and hydroxylation Reaction, and finally use silane coupling agent to graft, the reaction process is complicated, and high-energy ray treatment and chemical reaction are easy to damage the fiber

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