Preparation method of polyurethane composite material

Abstract

The invention discloses a preparation method of a polyurethane composite material. According to the preparation method, the injection pressure of reactants and the vacuum degree of a mold are controlled; and the limited reactants have proper operation time and low viscosity, and have the characteristics of low early-stage viscosity, slow viscosity increase, extremely high later-stage curing speed,short demolding time and the like in a high-temperature mold, and the composite material prepared by the method has excellent heat resistance and mechanical properties.

Description

technical field [0001] The invention relates to a method for preparing a polyurethane composite material, in particular to a method for preparing a polyurethane composite material using a high-pressure injection molding process. Background technique [0002] High-pressure resin transfer molding (HP-RTM) process technology is a new process introduced in recent years for mass production of high-performance composite materials. It uses prefabricated parts, steel film, vacuum-assisted exhaust, and high-pressure injection , so that the resin liquid quickly fills the mold cavity and solidifies. This process produces products with high efficiency, good dimensional stability, high quality, low cost of mass production of composite materials, and realizes diversified and complex structural products. [0003] At present, the resins commonly used in the HP-RTM process on the market are mainly epoxy resins and polyurethane resins, but there are three disadvantages: (1) The impregnation o...

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Problems solved by technology

[0003] At present, the resins commonly used in the HP-RTM process on the market are mainly epoxy resins and polyurethane resins, but there are three disadvantages: (1) The impregnation of the fibers by the resin is not ideal, and the porosity of the product is high; (2) The resin is operable The matching between time and molding speed is not good, and it is difficult to achieve high quality and high production speed; (3) In the mold cavity with large area and complex structure, it is impossible to predict and control, and the resin flow is not balanced

[0004] Patent CN106232671A discloses a composite fiber component and its manufacture. The technical solution is a fiber composite component obtained by impregnating fibers with a polyurethane reactive resin mixture formed of polyisocyanate, polyol, two or more thermally latent catalysts, etc., and its resin The molding speed is still slow, the glass transition temperature is only 110°C, and the heat resistance is not high enough; secondly, under the condition of adding flame retardants, its flame retardant performance is not high enough

The above performance still cannot meet the demand

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