Self-emulsifying polyurethanes epoxy sizing agent for carbon fibers and preparation method thereof

Abstract

The invention relates to a self-emulsifying polyurethanes epoxy sizing agent for carbon fibers and a preparation method thereof. The sizing agent comprises the following components in part by weight: 10 to 15 parts of self-emulsifying polyurethanes epoxy emulsion, 0.2 to 0.3 part of aid, and 84.7 to 89.8 parts of deionized water. The method for preparing the sizing agent comprises the following steps of: (1) preparing hydrophilic polyurethane prepolymer of the self-emulsifying polyurethanes epoxy emulsion; (2) preparing a prepolymer of which the end group is an epoxy group; (3) adding 6 to 20 parts of neutralizer into the prepolymer of which the end group is an epoxy group for neutralization, pouring the neutralized solution into water for dispersing, and removing the solvent through reduced pressure distillation to obtain the self-emulsifying polyurethanes epoxy emulsion; and (4) adding the aid and the deionized water into the polyurethanes epoxy emulsion in the ratio, and uniformly mixing to obtain the self-emulsifying polyurethanes epoxy sizing agent for the carbon fibers. The self-emulsifying polyurethanes epoxy sizing agent for the carbon fibers and the preparation method thereof have reasonable design. The sizing agent can improve the mechanical property of carbon fiber composite materials, and has excellent dilution stability.

Description

technical field [0001] The invention belongs to the field of carbon fiber sizing agents, in particular to a polyurethane epoxy sizing agent for self-emulsifying carbon fibers and a preparation method thereof. Background technique [0002] Carbon fiber has the characteristics of high strength, high modulus, electrical conductivity, thermal conductivity, high temperature resistance and corrosion resistance. As an important advanced composite material reinforcement, it has a wide range of applications in national defense, aerospace and other fields. However, during the molding process of composite materials, hairs are prone to appear on the surface of carbon fibers, which will affect the bonding with the base resin (mostly epoxy resin), and it is difficult to achieve the effect of strengthening and toughening. At present, people mainly use the method of coating a layer of emulsion type sizing agent on the surface of carbon fiber to increase the bonding strength between carbon f...

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Problems solved by technology

In the following Chinese patent applications: the application number is 200510063352.2 (the name is carbon fiber sizing agent and its preparation method), the application number is 200410064587.9 (the name is a preparation method of nano-SiO2 modified carbon fiber emulsion sizing agent), the application number is 02810272 .X (named sizing agent for carbon fiber, its aqueous dispersion, sizing-treated carbon fiber, sheets using the carbon fiber, and carbon fiber-reinforced composite materials), application number 02813985.2 (named sizing agent for carbon fiber, its water Dispersion, sizing-treated carbon fiber, sheets using the carbon fiber, and carbon fiber reinforced composite materials) involve some carbon fiber sizing agents and their preparation methods. The problems with these sizing agents are: (1) they all use external The method of emulsification is prepared by adding various emulsifiers and dispersing solvent-based epoxy resin in water, which has poor storage stability; (2) the sizing agent emulsion will be diluted into a system with a solid content of less than 5%, so that It is easy to cause effective ingredients to be separated out