Study of Microcellular Injection Molding of Bio-based/Biodegradable Plastics

本研究的目的是促进对微细胞注射成型的轻质、高性能生物基/可生物降解部件的基本理解和加工技术，并开发三维建模和仿真工具。方法是：(1)利用安装在微孔注塑机上的内部设计的新型在线高压狭缝模具流变仪，更好地了解生物基/可生物降解塑料的超临界流体溶液行为；(2)通过实验设计，建立生物基/可生物降解塑料的加工准则；(3)利用各种纳米粒子和生物纤维作为填料，促进对细胞成核和生长机制的理解，并开发最先进的三维建模和模拟工具；(4)通过广泛的表征和分析建模，建立各种微细胞生物基/可生物降解塑料的组成-工艺-结构-性能关系。人类社会从使用石油基塑料中受益匪浅。然而，这种繁荣是以不利的环境影响和消耗化石资源为代价的。虽然生物可降解的生物基塑料已经成功地从可再生资源中生产出来，但由于材料性能差，加工窗口窄，材料成本相对较高，其商业应用受到限制。这项研究可以为生物基塑料提供更大的加工窗口，实现具有复杂几何形状、改善材料性能、降低材料成本的环保生物基/可生物降解塑料部件的大规模生产，从而扩大其在许多工业领域的应用，最终帮助美国塑料工业在全球市场上获得竞争优势。此外，研究成果和活动将纳入现有的和新的制造工程课程，帮助教育学生关于发展环境友好材料和工艺的日益重要的意义。代表性不足的群体的学生将通过本科生研究经验补充招募参与本研究。

The objective of this research is to advance the fundamental understanding and processing technology of, and to develop three-dimensional modeling and simulation tools for, the mass production of lightweight, high-performance biobased/biodegradable components via microcellular injection molding. The approaches are to (1) achieve a better understanding of the biobased/ biodegradable plastic-supercritical fluid solution behavior utilizing an in-house designed novel in-line high-pressure slit die rheometer mounted on the microcellular injection molding machine; (2) establish guidelines for processing biobased/biodegradable plastics via design of experiments; (3) advance the understanding of cell nucleation and growth mechanisms by employing various nanoparticles and biofibers as fillers, and develop state-of-the-art, three-dimensional modeling and simulation tools; and (4) establish the composition-process-structure-property relationship of various microcellular biobased/biodegradable plastics via extensive characterization and analytical modeling.Human society has benefited tremendously from the use of petroleum-based plastics. However, this prosperity has come at the expense of adverse environmental impacts and at the mercy of depleting fossil-based resources. Although biodegradable biobased plastics have been successfully produced from renewable resources, their commercial application has been limited due to inferior material properties, narrow processing windows, and relatively high material costs. This research could enable a larger processing window for biobased plastics and realize the mass production of environmentally benign biobased/biodegradable plastic components with complex geometries, improved material properties, and reduced material costs, thus broadening their application in many industrial sectors and ultimately helping the U.S. plastics industry gain a competitive edge in the global market. Moreover, research results and activities will be incorporated into existing and new manufacturing engineering curricula, helping to educate students regarding the growing importance of developing environmentally friendly materials and processes. Students of underrepresented groups will be recruited through the Research Experiences for Undergraduates supplement to participate in this research.