PMI structural foam is a closed-cell rigid foam obtained by foaming methacrylic acid (MAA) and methacrylonitrile (MAN).
MAA- Mann * * * polymer sheet is obtained by bulk polymerization of MAA and Mann radical. At the foaming temperature of 180-230℃, the foaming agent embedded in * * * polymer was gasified to obtain PMI foamed sheet. At the same time of high temperature foaming, the adjacent cyano group (-CN) and carboxyl group (-COOH) in Manman polymer undergo nucleophilic addition reaction to form cyclic imide structure. The strong polarity and high rigidity of this structure endow PMI foam with good comprehensive properties.
At present, the best PMI bubble in China is the technology of Zhejiang Zhongke Hengtai and Institute of Chemistry of Chinese Academy of Sciences, which is widely used in domestic aerospace.