Supercritical Fractionation of Crystalline Polymers Near the Upper Critical End Point (Expedited Award)

结晶聚合物在上临界终点附近的超临界分级（加急奖）

• 批准号: 8612694
• 负责人: Paul Ehrlich
• 金额: $ 9.59万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-09-01 至 1988-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8612694&HistoricalAwards=false
• 关键词: Supercritical; Fractionation; Crystalline; Polymers; Near

The efficient fractionation of crystalline polymers should be possible near the upper critical end point (UCEP) which, for a sharp polymer fraction, is connected to the triple point (melting point) of the polymer by a three-phase line along which solid-liquid-gas equilibrium exists. By operating at temperatures slightly below that of the UCEP, such fractionation can be performed under conditions where solid-supercritical fluid equilibrium exists. The advantages associated with supercritical fluid extraction (SFE) should therefore be gained. The fractionation and relevant phase equilibrium near the UCEP are to be studied for the system polyethylene-n-propane at about 100-140oC and 400-600 bar. Under these conditions, fractionation induced by differences in molecular weight, as well as in microstructural irregularity (short-chain branching), is expected to occur.

在上部临界端点（UCEP）附近应进行有效的结晶聚合物分馏，该端点的上临界端点（UCEP），对于尖锐的聚合物分数，通过沿着固体液 - 液体平衡存在的三相系列连接到聚合物的三相（熔点）。 通过在略低于UCEP的温度下运行，可以在存在固体智力平衡的条件下进行这种分级。 因此，应获得与超临界流体提取（SFE）相关的优点。 在大约100-140oC和400-600 bar的系统聚乙烯-N-丙烷中，应研究UCEP附近的分馏和相关相位平衡。 在这些条件下，预计将发生由分子量差异以及微结构不规则（短链分支）引起的分馏。