Method for preparing high-density polymethacrylimide foam material

Abstract

The invention discloses a method for preparing a high-density polymethacrylimide foam material. The high-density polymethacrylimide foam material is prepared by taking methacrylic acid and methacrylonitrile as comonomers and N,N'-diamine diphenylmethane type bismaleimide as a density control agent, adding an initiating agent, a foaming agent, a cross-linking agent and a nucleating agent to copolymerize so as to obtain a methacrylic acid and methacrylonitrile copolymer resin matrix, and further performing high-temperature foaming and thermal treatment. By adopting the method, PMI (Polymethacrylimide) foam with the density of 320kg / m<3> at most is prepared, and the difficult problem that foam plastic with the density greater than 200kg / m<3> has less possibility of being prepared from the polymethacrylimide foam is solved. The material can be applied to fields requiring PMI foam plastic with high density, such as airplanes and radar shells.

Description

technical field [0001] The invention relates to a method for preparing a foam core material, in particular to a method for preparing a high-density polymethacrylimide (PMI) foam material. Background technique [0002] PMI foam is a high-performance foam based on methacrylic acid / methacrylonitrile copolymer. Under the same density, PMI foam is currently the foam with the highest strength and stiffness, and it also has excellent heat resistance and creep resistance. PMI foam was first developed by German Degussa company in 1972, and now it has developed a number of product series with different uses and performances. High-performance sandwich structure composites prepared with high-performance PMI foam as the core material have been widely used in many fields such as rockets, aircraft, ships, automobiles, trains, wind power, medical equipment, and sporting goods. Although the research work in this field has been started in China, the research is still in the experimental ...

AI Technical Summary

Problems solved by technology

[0003] Polymethylpropionimide foams of different densities can be used in various fields, but experiments have found that the same formula and process, the density error of copolymer foams prepared in different batches is relatively large, and it is difficult to obtain a density greater than 200kg / m 3 Styrofoam

It may be due to the reaction of the copolymer during the foaming process and the release of small molecules (such as H 2 O) The copolymer can be foamed, and the residual initiator can also be decomposed to release gas, which can make the copolymer foam, and the total amount of gas is relatively large

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