Method for recovering carbon-fiber enhanced epoxy resin composite material

Abstract

The invention relates to a method for recovering a carbon-fiber enhanced epoxy resin composite material. In the existing method, the requirement for equipment is high and the recovery cost is large. The method comprises the following steps of: cutting materials needing to be decomposed into blocks with the volume being 5cm<3>, putting the blocks in a backflow device containing acid liquor, heating for 5-20 minutes at the temperature of boiling point, cleaning and carrying out vacuum drying; then putting the obtained mixture into a reaction kettle, adding an organic solvent and an oxidizing agent, firstly heating, then cooling to normal temperature, and obtaining a primary product; and after cleaning, putting a solid product in the primary product into industrial acetone solution for dipping, obtaining recovered carbon fiber and carrying out pressure-reduced distillation on a liquid product to obtain phenol and derivatives thereof. In the method, reaction under low temperature and low pressure is realized and has the advantages of moderate reaction condition, easy control of reaction, fewer side products, no pollution basically and no corrosion to equipment and the like, so that the method is a green recovering method.

Description

technical field [0001] The invention belongs to the technical field of polymers, and relates to a method for recycling waste thermosetting resin composite materials, in particular to a method for recycling 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 , automobile industry, sporting goods and other high-tech fields have wide application. 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 thermosetting res...

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 reaction kettle at 200-350°C. In this invention, the reaction mother liquor can be used many times and recovered to obtain mechanical Fibers with little loss of performance