CO_2在固态聚丙烯/滑石粉复合材料中的溶解和扩散

Dissolution and Diffusion of CO_2 in Soild-State PP/talc Composites

利用重量分析的方法测定了温度分别为343.15、373.15和393.15 K,压力0-16 MPa范围内,CO2在聚丙烯（PP）、PP/滑石粉和界面改性PP/滑石粉复合材料中的溶解度和扩散系数。CO2在未经界面改性PP/滑石粉复合材料中的溶解度低压下大于而高压下小于其在纯PP中的溶解度,在经过界面改性的PP/滑石粉复合材料中的溶解度小于其在纯PP和未经界面改性复合材料中的溶解度。CO2在PP/滑石粉复合材料中的扩散系数小于其在纯PP中的扩散系数,填料含量越大扩散系数越小。通过S-L状态方程关联了CO2在纯PP和经过界面改性的PP/滑石粉复合材料非晶区的溶解度,并计算了CO2对聚合物基体的溶胀情况,证实了填料对聚合物分子链运动的阻碍作用。

Gravimetric method was adopted polypropylene （PP）, polypropylene/talcum （talc） to measure solubility and diffusivity of C02 in pure composites and interface modified PP/talc composites at temperatures 343.15, 373.15 and 393.15 K respectively and pressure range of 0-16 MPa. Compared with the solubility of CO2 in pure PP, the CO2 solubility in PP/talc composites without interface modification is larger at lower pressure, but smaller at higher pressure. Solubility of CO2 in interface modified PP/talc composites is less than that in pure PP and PP/talc composites without interface modification. Diffusion coefficient of CO2 in PP/talc composites is smaller than that in pure PP and decreases with the increase of talcum content. Solubility of CO2 in amorphous region of pure PP and interface modified PP/talc composites were correlated with the Sanchez-Lacombe state equation in conjunction with the interaction parameters. The swelling degree of polymer matrix caused by CO2 was also predicted, which could prove the filler hinderance for the movement of polymer chains.