Polyurethane composite material and preparation method thereof

Abstract

According to the polyurethane composite material and the preparation method thereof, the preparation method can improve the infiltration effect of a mixed material on a reinforcing material, and is particularly suitable for an HP-RTM process needing rapid curing, product defects are reduced, the production efficiency is improved, and meanwhile the product is excellent in toughness and good in mechanical property. The preparation method comprises the following steps: 1) mixing an isocyanate component and an isocyanate reactive component; and 2) injecting the obtained mixed material into a moldwith a built-in reinforcing material, and carrying out a reaction to obtain the polyurethane composite material; wherein the isocyanate component comprises polymerized MDI and an MDI monomer, and theisocyanate reactive component comprises polyether polyol and a catalyst, and optionally comprises small molecular alcohol and an internal releasing agent.

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, 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 of the fibers by the resin is...

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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 composite fiber parts and its manufacture. The technical solution is obtained by impregnating fibers with a polyurethane reactive resin mixture formed of polyisocyanate prepolymers, polyols, two or more thermally latent catalysts, etc. Parts, the resin molding speed is still slow, the mechanical strength is insufficient, the glass transition temperature is only 110°C, and the heat resistance is not high enough

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