Recovery method of carbon-fiber reinforced epoxy composites

Abstract

The invention relates to a recovery method of carbon-fiber reinforced epoxy composites. A method in the prior art has defects of strict reaction requirements and high recovery cost. The method provided in the invention comprises the steps of: cutting composites needing to be decomposed into blocks with volumes smaller than 5 cubic centimeters, placing the blocks in a reflux device filled with acid solution, heating for 5-30 minutes at a boiling temperature, drying in vacuum after washing the composites, placing the dried composites in a sealed reactor, adding materials containing hydroxyl and oxidizing agent into the sealed reactor, heating, then cooling the material to normal temperature to obtain primary products, placing and dipping solid products of the primary products in industrial acetone solution after washing the solid products, recycling to obtain carbon fiber, and carrying out liquid separation, extraction and distillation for liquid products to obtain phenol and phenol derivatives. According to the invention, the recovery is carried out under low temperature and low pressure; the reaction condition is mild; the recovery can be controlled easily; the recovery has few by-products, almost no pollution, and no equipment corrosion. The recovery method is a green recovery way.

Description

technical field [0001] The invention belongs to the technical field of macromolecules, and relates to a method for recycling waste thermosetting resin composite materials, in particular to a method for recycling carbon fiber reinforced epoxy resin composite materials. technical background [0002] Carbon fiber (CF) / epoxy resin (EP) composite material (referred to as CF / EP composite material) has the characteristics of low density, high specific strength and specific modulus, especially carbon fiber / epoxy resin composite material in the aviation field, It is widely used in high-tech fields such as the automobile industry and sporting goods. With the development of low-carbon economy, the use of carbon fiber / epoxy resin composite materials in various fields has grown rapidly, and has continued to expand to emerging fields such as: new energy, high-speed trains, etc. With the application of carbon fiber / epoxy resin composite materials in these high-tech fields, the waste of th...

AI Technical Summary

Problems solved by technology

This method can obtain fibers with a clean surface and no defects, but the nitric acid used is a strong corrosive acid, the operation safety factor is low, the corrosion resistance of the reaction equipment is high, and it can only be applied to epoxy resin composite materials cured by amines Published patent CN200610151145.7 is to add thermosetting epoxy composite material, tetralin or decahydronaphthalene-based decomposition liquid and 10-30% catalyst into a stainless steel closed reaction kettle, and heat it at 280-350°C to make Epoxy resin is degraded, the reaction temperature required by this invention is high, and a large amount of catalyst is used, the loss of mechanical properties of the obtained fiber is also large, and the value of reuse is not great; their patent 200710144538.X published in 2007 is The water phase is used as the reaction environment, and 10-30% of some inorganic substances are assisted as catalysts, and the reaction is carried out at 4-6Mpa, 260-380°C

Although the raw material water used in this invention is cheap and has a wide range of sources, the method requires higher temperature and higher pressure, which requires higher temperature and pressure resistance of the reaction equipment and a large amount of catalyst; the patent 200910046524.3 disclosed by Zhang Jianqiu et al. The water phase is used as the reaction environment, but heteropoly acid is used as the catalyst, which reduces the amount of catalyst used, but the reaction still needs to be carried out at a high temperature of 250-270 ° C, and the price of the catalyst is relatively expensive; Tang Tao et al. published in 2010 Patent 201010122570.X proposes to put water, phenolic compounds, and alkali metal catalysts as the reaction mother liquor and carbon fiber-reinforced epoxy resin in a sealed reaction kettle at 200-350°C. In this invention, the reaction mother liquor can be used many times and recovered to obtain Fibers with little loss of mechanical properties