Conversion/Recycling of Ethylene-Based Copolymers: Is it Feasible in SCF-Water Mixtures (SGER)

小行星9509608 回收聚合物和共聚物是一个必须解决的技术问题，如果要减少美国填埋的固体废物的数量。 目前的挑战是开发技术，以经济的方式进行回收，而不会同时产生溶剂废物，这将抵消任何环境效益。 许多研究人员建议使用超临界水将聚合物分解成它们的结构单元。 在该程序中提出了一种不同的方案，其中共聚物被转化成可能具有比起始材料更高的商业价值的替代结构。 设想的转化过程将使用近临界水而不是超临界水，这降低了该过程的热能需求。 各种聚合物和共聚物在近临界溶液中的溶解度特性的差异将有助于将一种类型的共聚物与另一种类型的共聚物分离。 这种新的转化/回收工艺的成功开发在很大程度上取决于对工艺溶剂溶液中这些共聚物的良好理解。 然而，本研究的重点是确定这些想法的可行性，而不是深入了解该过程的热力学和动力学。 将进行选定的溶解度和动力学实验，以突出该工艺的潜力。 这种新工艺概念的成功示范将为制定更详细的建议奠定基础，以确定热力学、动力学和分离变量，从而确保该工艺的经济可行性。

9509608 McHugh Recycling polymers and copolymers is a technological problem that must be addressed if the amount of solid waste being landfilled in the United States is to be reduced. The challenge is to develop technology that performs the recycling in an economic manner without the concomitant generation of solvent waste that would negate any environmental benefits. Many researchers have suggested decomposing polymers into their building blocks using supercritical water. a different scenario is suggested in this program where the copolymer is converted into an alternate structure that potentially has higher commercial value than the starting material. The envisioned conversion process would use near-critical water rather than supercritical water which reduces the thermal energy requirements of the process. The differences in the solubility characteristics of the various polymers and copolymers in the near-critical solution would facilitate separating one type of copolymer from another. The successful development of this new conversion/recycling process to a great extent depends on a good understanding of these copolymers in the process solvent solution. However, the focus of this proposed study is to determine the feasibility of these ideas rather than to develop an in-depth understanding of the thermodynamics and kinetics of the process. Selected solubility and kinetics experiments will be performed to highlight the potential of this process. The successful demonstration of the concepts for this new process would create the groundwork for the development of a more detailed proposal to determine the thermodynamic, kinetic, and separations variables that would insure the economic viability of the process.