Enhanced Polymer-Polymer Blending and Polymer-Fiber/Particle Compounding Using Supercritical Carbon Dioxide

该项目将探索在基于单螺杆和双螺杆挤出工艺的先进聚合物和复合材料的混合和复合中使用超临界(稠密气体)二氧化碳的潜力。二氧化碳是一种廉价、无毒、不受监管的溶剂。它不仅可以在传统加工操作中取代液体有机溶剂，而且由于在超临界状态下具有独特的性质，它可以在聚合物和复合材料行业带来全新的制造工艺和产品。由于50%以上的商业聚合物是以共混或化合物的形式存在的，因此，聚合物-聚合物共混和聚合物-纤维/颗粒复合的进步可能会对聚合物加工产生最大的影响。超临界二氧化碳由于其无害的性质，目前在食品工业中被广泛使用。围绕化工和塑料行业的监管环境创造了将超临界流体的一些成功成果转化为聚合物加工领域的机会。实验将研究超临界二氧化碳在各种聚合物中的溶解，以确定对玻璃化转变温度、熔体粘度、链流动性、密度和表面张力的影响。这些效应可用于改善聚合物和复合材料加工中的混合、润湿性和分子扩散。为了促进将基础研究转化为应用，该项目包括从新工艺概念到挤出机螺杆设计的多个层面的工业参与。研究人员将与包括材料供应商和挤出机制造商在内的行业咨询小组密切合作，开发使用超临界二氧化碳在机械和反应性共混和复合中增强聚合物-聚合物、聚合物纤维和聚合物-纳米颗粒混合的技术。

This project will explore the potential of using supercritical (dense gas) carbon dioxide in the blending and compounding of advanced polymers and composites based on single and twin-screw extrusion processes. Carbon dioxide is an inexpensive, nontoxic, and unregulated solvent. Not only can it replace liquid organic solvents in conventional processing operations but, due to the unique properties available in the supercritical state, it can lead to completely new manufacturing processes and products in the polymer and composite industry. Since more than 50% of all commercial polymers are in the form of blends or compounds, perhaps the greatest impact on polymer processing can be achieved through advances in polymer-polymer blending and polymer-fiber/particle compounding. Supercritical carbon dioxide is currently being used extensively in the food industry due to its benign nature. The regulatory environment surrounding the chemical and plastic industries creates an opportunity to translate some of the successes of supercritical fluids to the polymer processing area. Experiments will investigate the dissolution of supercritical carbon dioxide into various polymers to establish the affect upon glass transition temperature, melt viscosity, chain mobility, density, and surface tension. These effects can be used to improve mixing, wettability, and molecular diffusion in polymer and composite processing. To facilitate the transfer of fundamental research into application, the project includes several levels of industrial involvement ranging from new process concepts to extruder screw design. The researchers will work closely with the industrial advisory group, including material suppliers and extruder makers, to develop techniques of using supercritical carbon dioxide to enhance polymer-polymer, polymer-fiber, and polymer-nanoparticle mixing in mechanical and reactive blending and compounding.