Study on Microcellular Foaming of Linear Low-density Polyethylene/Ethylene-Propylene-Diene Monomer Blends Using Supercritical Carbon Dioxide LLDPE/EPDM共混物的超临界CO2微孔发泡研究

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.