Supercritical Fluid - Crystal Phase Fractionation of Polymers: Polyethylene-Propane

相平衡将被确定为聚乙烯-丙烷 系统，包括固-液和液-气相边界， 使用视图单元（等值线方法）。 这种方法在 在100至130度下使用普通聚乙烯的早期工作 摄氏度和9,000到11,000磅/平方英寸。 数据将收集于 高密度聚乙烯级分。 搅动的影响 在结晶过程中对聚合物形态的影响也将被检查。 这些数据将用于设计和测试半连续工艺， 高密度聚乙烯通过结晶从 超临界流体。 虽然聚合物已被证明是 可通过分子量从超临界流体中分离， 这些方法基于液相和气相的共存。 这里尝试的方法将基于固体/超临界气体 共处 先进的聚合物技术在以下场景中发挥着核心作用： 开发先进的工程材料。 一个关键的方面， 先进的聚合物制造是生产聚合物， 分子量分布 通过经济地分离聚合物 聚合后的分子量分子 成为生产先进材料的另一种工具。

Phase equilibrince will be determined for the polyethylene - propane system, including both solid-liquid and liquid-gas phase boundaries, using a view cell (isopleth method). This method was successful in earlier work with unfractionated polyethylene at 100 to 130 degrees centigrade and 9,000 to 11,000 psi. Data will be collected on fractions of high density polyethylene. The effect of agitation during crystallization on polymer morphology will also be examined. The data will be used to design and test a semi-continuous process for the fractionation of high density polyethylene by crystallization from a supercritical fluid. Although polymers have been shown to be fractionable by molecular weight from supercritical fluids, such processes have been based on the coexistence of liquid and gas phases. The process attempted here will be based on solid/supercritical gas coexistence. Advanced polymer technology plays a central role in scenarios for development of advanced engineering materials. One critical aspect of advanced polymer manufacturing is production of polymers with a narrow molecular weight distribution. By economically separating polymer molecules by molecular weight after polymerization this technology becomes another tool for producing advanced materials.