Experimental Study of High Pressure Copolymer Solution Behavior

本项目的目的是研究片段-溶剂和片段-共溶剂氢键对乙烯基共聚物溶液相行为的作用。实现这一目标的方法是通过实验研究由极性/非极性、统计随机共聚物、极性和非极性溶剂和共溶剂组成的溶液的相行为。通过控制聚合物主链中非极性基团和极性基团的浓度，可以系统地改变共聚物的极性和氢键能力。溶剂从低分子量的非极性碳氢化合物到高极性的氢键碳氢化合物不等。二甲醚和乙醇等共溶剂将与非极性溶剂一起使用，以确定氢键和极性对相行为的重要性。云点曲线和二元和三元相图将在高达448 K的温度和高达275 MPa的压力下构建，这些条件也包括用于乙烯基共聚物的自由基聚合过程。数据将使用Sanchez-Lacombe状态方程的现有形式和修改后的形式来明确说明氢键。

The objective of this project is to investigate the role of segment-solvent and segment-cosolvent hydrogen bonding on the phase behavior of ethylene-based copolymer solutions. The approach used to reach this objective is to experimentally investigate the phase behavior of solutions which consist of polar/nonpolar, statistically random copolymers with polar and nonpolar solvents and cosolvents. The polarity and hydrogen bonding capabilities of the copolymers will be systematically varied by controlling the concentration of nonpolar and polar groups in the polymer backbone. The solvents will vary from the low-molecular-weight, nonpolar hydrocarbons to highly polar, hydrogen bonding hydrocarbons. Cosolvents such as dimethyl ether and ethanol will be used with the nonpolar solvents to determine the importance of hydrogen bonding and polarity on the phase behavior. Cloud-point curves and binary and ternary phase diagrams will be constructed at temperatures up to 448 K and at pressures up to 275 MPa--conditions which also bracket the free-radical polymerization process that is used for ethylene-based copolymers. The data will be modeled using the Sanchez-Lacombe equation of state in its present form and in a form revised to explicitly account for hydrogen bonding.