Polyimide prepreg, composite material and preparation method thereof

Abstract

The invention provides a polyimide prepreg, a composite material and a preparation method thereof. Thermosetting polyimide resin and reinforced fabric are adopted for preparation through a solution method. As for the reinforced fabric, thermoplastic polyimide fibers serve as lining yarn, a single-layer or multi-layer fiber fabric is woven into a whole, the melting point temperature of the thermoplastic polyimide fibers is lower than the gel point temperature of thermosetting polyimide resin, and the decomposition temperature of the thermoplastic polyimide fibers is higher than the glass-transition temperature of the thermosetting polyimide resin. The reinforced fabric is prepared by taking the thermoplastic polyimide fiber as the lining yarn, the thermoplastic toughening bodies are uniformly distributed, the content of the thermoplastic toughening bodies is controllable, the fabric structure of the two-dimensional/multi-dimensional toughening bodies is formed, the thermosetting polyimide composite material can be effectively toughened after the prepreg is prepared and cured, and the toughness and the impact strength of the composite material are improved.

Description

technical field [0001] The invention relates to a polyimide prepreg, a composite material and a preparation method thereof, belonging to the technical field of composite materials. Background technique [0002] Polyimide is one of the organic polymer materials with the best comprehensive performance. Its heat-resistant temperature can reach above 600°C, and its long-term use temperature ranges from 200 to 500°C. At present, polyimide composite materials are commonly used in the world. The main material of high temperature resistant and high load bearing structure. In recent years, polyimide has formed a resin-based composite material system covering four generations with a temperature resistance from 280°C to 480°C. At present, the high temperature resistant thermosetting polyimide resin system is mainly divided into two types according to the state of the resin, one is polyimide synthesized by PMR method, this type of resin is not imidized in the synthesis, and one is solu...

AI Technical Summary

Problems solved by technology

At present, polyimide prepregs are mainly prepared by solution method, which can realize the continuous preparation of fabric prepregs. For the preparation of non-weft polyimide prepregs, due to the low viscosity of polyimide resin solution , after the fiber passing through the spreading device passes through the dipping tank, the fiber shrinks under capillary action, and the prepared weft-free prepreg often has cracks, which cannot realize continuous production. At the same time, the prepreg prepared by the solution method is in the solution After volatilization, the phenomenon of fiber distortion often occurs, and the preparation of high-quality polyimide prepreg cannot be realized

[0004] The current method of preparing polyimide prepregs is mainly the method of manual brushing with resin glue or prepreg fabrics with prepreg machines. Due to the buckling of fabric fibers, the mechanical properties of composite materials are affected, and the interlining yarns in warp knitted fabrics Generally, it is glass fiber, and the prepared composite material fiber has certain buckling, and the glass fiber lining yarn affects the performance of the composite material

[0005] The toughening of polyimide composites has attracted widespread attention in recent years. The current methods are based on the toughening modification of the main chain structure of the thermosetting polyimide resin and the blending toughening modification of thermoplastic polymers. The two methods have a certain impact on the manufacturability and temperature resistance of thermosetting polyimide. The method of preparing tough composite materials by blending thermoplastic resins has a large viscosity and a large amount of thermoplastic resin. The viscosity of the system is large. Bubbles are difficult to exclude, which affects the manufacturability of composite material preparation; on the other hand, it is difficult to mix the thermoplastic system with the thermosetting system evenly, resulting in poor performance uniformity of the prepared composite material