热塑性聚氨酯微孔发泡材料的表观密度与其力学性能的关系  

Relationship between Apparent Density and Mechanical Properties of Microcellular Thermoplastic Polyurethane Foam

作　　者：刘芳 赵志刚[1] 杨雪 潘鸽 石彤非 许东华[1] 翟文涛[3] Fang Liu;Zhi-gang Zhao;Xue Yang;Ge Pan;Tong-fei Shi;Dong-hua Xu;Wen-tao Zhai(State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022;School of Applied Chemistry and Engineering,University of Science and Technology of China,Hefei 230026;School of Materials Science and Engineering,Sun Yat-Sen University,Guangzhou 510275)

机构地区：[1]中国科学院长春应用化学研究所高分子物理与化学国家重点实验室,长春130022 [2]中国科学技术大学应用化学与工程学院,合肥230026 [3]中山大学材料科学与工程学院,广州510275

出　　处：《高分子学报》2021年第4期388-398,I0003,共12页Acta Polymerica Sinica

基　　金：吉林省科技发展计划支持项目(自然科学基金)(基金号20200201239JC);国家自然科学基金面上项目(基金号51873226);高分子物理与化学国家重点实验室开放课题基金(基金号2019-10)资助项目.

摘　　要：用高压CO2流体通过升温发泡法制备了一系列不同表观密度的热塑性聚氨酯(TPU)微孔发泡材料,探究了TPU发泡材料的表观密度与其力学性能的关系.微孔发泡材料的泡孔结构和表皮结构由扫描电子显微镜表征;不同表观密度材料的力学性能利用万能材料试验机和旋转流变仪表征.研究发现:TPU微孔发泡材料的表观密度主要是由材料皮层厚度占比和泡孔层密度决定的,皮层厚度占比越小和泡孔面积占有率越高,泡沫的表观密度越小;微孔发泡材料在线性应变区的压缩模量E与材料表观密度ρ的关系为:E∝ρ1.7,符合泡沫材料压缩模量与表观密度呈指数关系的基本结论;循环压缩实验中,随微孔发泡材料表观密度减小,损耗百分比增大,残余应变减小;流变实验中,微孔发泡材料的模量随表观密度变化没有明显的变化,阻尼因子tanδ随泡沫表观密度变化不呈单一的规律性.同时,阐明了微孔发泡材料的压缩模量E和损耗百分比随表观密度变化的机理.A series of microcellular thermoplastic polyurethane foams with different apparent densities were prepared by temperature-increasing foaming method with high-pressure CO2 as blowing agent,and the relationship between the apparent density and mechanical properties was investigated.The structure of microcellular thermoplastic foam was characterized by scanning electron microscopy.The mechanical properties of the materials with different apparent densities were characterized by universal material testing machine and rotational rheometer.The results show that the apparent density of the microcellular thermoplastic polyurethane foam is mainly determined by the thickness ratio of the skin layer and the area occupation of cell.The smaller the ratio of the thickness of the skin layer and the higher the area occupation of cell,the smaller the foam density;the relationship between compression modulus E and apparent densityρof the samples in the linear strain region is as follows:E∝ρ1.7,which is consistent with the basic conclusion that the relationship between modulus and density of foam materials is exponential;in the cyclic compression experiment,as the density of the foam material decreases,the residual strain decreases,and the hysteresis increase;in the rheological experiment,the modulus of the foamed material does not change significantly with the density,and the damping factor tanδdoes not vary monotonically with the foam density.At the same time,the dependence of compression modulus E and hysteresis with foam density was also explained.

关 键 词：聚氨酯微孔发泡材料 皮层 表观密度 力学性能 流变 

分 类 号：TQ328[化学工程—合成树脂塑料工业]