Polymethacrylimide (PMI) foam was obtained by two steps: ( 1 ) a expandable tablet of MI/AN was prepared via bulk copolymerization of monomers mixture; (2) PMI foam was produced by heating the expandable tablet at 190 ℃ for 1 hour. Electronic universal testing machine, digital cameras and SEM were utilized to investigate the tensile and compress properties of the foam. The results showed compression strength was significantly improved after heat treatment and the yield stress occurs at a greater strain. Tensile strength increased slightly, but the elongation at break decreased significantly. Compression crush dominated by buckling of cell edges and walls, forming yield layer simultaneously. Finally, it propagated to entire structure and failed.%聚甲基丙烯酰亚胺(PMI)泡沫通过两步制得:(1)本体聚合得到可发性的甲基丙烯酸/丙烯腈共聚物板;(2)190℃发泡1 h制得PMI泡沫.采用电子万能试验机、数码照相机和扫描电子显微镜对压缩及拉伸性能进行了分析.表明热处理之后泡沫压缩强度有大幅提高;拉伸强度提高幅度较小,但断裂伸长率明显下降;压缩破坏源于泡孔结构的皱弯变形,并形成屈服层,呈现出层层扩散式破坏特征.
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