Molecular Thermodynamics of Polymer/Mixed-Solvent Systems for Process/Product Design and Environmental-Protection Technology

John Prausnitz CTS-9411366聚合物/混合溶剂体系的热力学性能对于各种应用是必要的，包括表面声波蒸汽传感器；使用聚合物膜从废气中回收有机蒸汽；渗透汽化和其他聚合物膜分离过程；聚合物脱挥；气相光接枝；以及涂料和涂料的最佳配方。为了合理的工艺和产品设计，我们需要新的实验数据和基于分子热力学的新的关联式。将测量几种聚合物/混合溶剂体系的汽液平衡，包括稀溶液(使用取样平衡池)和浓溶液(使用重量法聚合物溶胀技术)。此外，还将测量各种聚合物/混合溶剂体系的theta温度，并将其与一种程序进行关联，该程序涉及测量(通过扫描)一定范围内聚合物浓度的浊点温度，并外推到单位体积分数的聚合物。这项研究的目的是为这些体系的热力学性质提供实验数据和关联，以便在声波蒸汽传感器、VOC膜从气流中分离、气相光接枝和涂料配方中广泛应用。该项目的成功完成将大大加强这些领域的知识和技术基础，使之能够更好地设计现有流程并开发新的流程和产品。将要使用的实验技术是对P.I.S等人开发的现有技术的修改，以解决混合溶剂的问题。相关工作将是与P.I.S之前发展的微扰硬球链状态方程。Theta温度是无限长的聚合物链长和无限稀释的聚合物在溶剂中的旋节温度。P.I.和同事们已经开发了一个计算程序。对于实验，给出了一个初步的系统列表，这些系统是针对具体的技术应用而定的。给出了重力法的典型误差分析。

John Prausnitz CTS-9411366 Thermodynamic properties of polymer/mixed-solvent systems are necessary for a variety of applications including surface acoustic-wave vapor sensors; recovery of organic vapors from waste-air streams using a polymeric membrane; pervaporation, and other polymeric membrane-separation processes; polymer devolatilization; vapor-phase photografting; and for optimum formulation of paints and coatings. For rational process and product design, we require new experimental data and new correlation based on molecular thermodynamics. Vapor-liquid equilibria for several polymer/mixed-solvent systems will be measured , both for dilute polymer solutions (using a sampled equilibrium cell ) and concentrated solutions (using a gravimetric polymer swelling technique). Also, the theta temperature for various polymer/mixed-solvent systems will be measured and correlated with a procedure that involves measuring (by scanning) the cloud-point temperatures for a range of polymer concentrations and extrapolating to unity volume fraction polymer. The goal of the study is to provide experimental data and correlations for thermodynamic properties of these systems for a wide range of applications in acoustic-wave vapor sensors, VOC membrane separation from air streams, vapor-phase photo-grafting, and paint formulation. The successful completion of the project would significantly enhance the knowledge and technology base in these areas, enabling better design of existing processes and development of new processes and products. The experimental techniques to be used are modifications to existing techniques developed by the P.I.'s and others, to account for mixed solvents. The correlational work will be with the P.I. 's previously developed Perturbed Hard-Sphere-Chain equation of state. The theta temperature is the spinodal temperature in the limit of infinite polymer chain length and infinite dilution of the polymer in the solvent. A program for this calculation has been develop ed by the P.I. and co-workers. For the experiments, a tentative list of systems is given, and these are keyed to the specific technological application. A typical error analysis for the gravimetric technique is given.