发泡工艺对环氧微孔发泡材料压缩性能的影响

利用化学发泡法与空心玻璃微球填充法,制备出具有不同泡孔结构的环氧树脂基微孔发泡材料,研究了发泡工艺对发泡行为的影响,以及不同工艺下泡孔结构对材料压缩性能的影响。结果表明,两种方法制备出来的发泡材料泡孔形态都保持规则的圆形;泡孔尺寸相差较小;无机玻璃壁的强度大于树脂组成的泡孔壁,导致空心玻璃微球填充环氧(EP–HGM)发泡材料的压缩强度、压缩弹性模量、比强度和比模量比化学发泡环氧(EP–CFA)发泡材料大。当密度较低时,EP–HGM发泡材料出现大量玻璃微珠破裂导致的裂纹产生并扩展,使得材料破坏失效,最终导致其应力–应变曲线在平台区终止;而EP–CFA发泡材料的泡孔被压缩,树脂基体变形,没有裂纹产生,应力–应变曲线始终保持完整的“三阶段”。

Effect of Foaming Process on Compression Properties of Epoxy Microcellular Foamed Materials

Epoxy microcellular foamed materials with different foam structures were prepared by chemical foaming method and hollow glass microsphere filling method. The influence of foaming process on foaming behavior and the influence of foam pore structure on material compression property under different process were studied. The results show that the morphology of foams prepared by the two methods is round and regular. The bubble size difference is small;the strength of the inorganic glass wall is greater than that of the foam wall composed of resin,resulting in higher compression strength,compression modulus,specific strength and specific modulus of EP–HGM foaming material than EP–CFA foaming material. When the density is low,a large number of glass microbeads in EP–HGM foamed material break,leading to the generation and expansion of cracks,resulting in the failure of the material and the termination of its stress-strain curve in the platform area. However,EP–CFA foam material has its bubbles compressed,the resin matrix is deformed,and no cracks are generated,and the stress-strain curve is always maintained in the "three stages".