LLDPE/EPDM共混物的超临界CO2微孔发泡研究

研究了线性低密度聚乙烯(LLDPE)/三元乙丙橡胶(EPDM)橡塑共混物在超临界CO_2中的微孔发泡行为。利用扫描电子显微镜对发泡样品的泡孔形貌进行了分析和表征;采用差示扫描量热仪分析了共混物的热性质;分别利用旋转流变仪和万能试验机分析得到样品的流变性能和力学性能。采用一定量的LLDPE与EPDM共混,压制标准试样,然后在高压反应釜中进行发泡,讨论了LLDPE/EPDM共混物中橡塑的质量比、饱和温度、饱和压力对材料泡孔结构和泡孔均匀性的影响。利用超临界CO_2作物理发泡剂,对发泡条件进行优化,可得到泡孔尺寸规整、泡孔密度高且回弹性和韧性较好的发泡闭孔材料。

Study on Microcellular Foaming of Linear Low-density Polyethylene/Ethylene-Propylene-Diene Monomer Blends Using Supercritical Carbon Dioxide

Microcellular foaming of LLDPE/EPDM blend was studied by using supercritical carbon dioxide.Scanning electron microscope was employed to analyze and characterize the morphology of the foaming sample.Thermal properties of the blend was analyzed by differential scanning calorimeter.Rheology behavior and mechanical properties of the sample were studied by rotational rheometer and universal tester microtester respectively.The LLDPE/EPDM blend and compressed standard sample were first obtained,then they were foamed at the high pressure reaction kettle.The impact of foaming parameters including rubber and plastic mass ratio,saturation temperature and saturation pressure on the foaming material's cell structure and cell uniformity were discussed.Using supercritical carbon dioxide as physical foaming agent and optimizing the foaming condition could obtain the closed-cell foaming material which possessed uniform morphology and large bubble density.Meanwhile,the material also presented good toughness and rebound resilience.