FMSG ECO: Melt Mastication for Upcycling of Polyolefins

世界范围内对食品、医疗产品和消费品的高功能软包装的需求正在增长，但一次性使用的塑料也造成了环境污染。目前的材料不能回收，因为它们的异质性以及在收集、分离、清洁和再加工方面的相关挑战。虽然化学回收方法正在迅速发展，但这些方法需要很高的能量投入，并且失去了内在的材料价值。该项目将通过创造一种单一聚合物类型的高性能阻隔薄膜的制造工艺，增加柔性薄膜的回收利用。工业、经济和社会效益分别包括：(1)用于大批量应用的薄膜增强的功能特性；(2)与当前加工系统兼容的技术推动的成本竞争力；以及(3)通过简化材料系统实现的极大增强塑料回收利用。研究计划包括推进新型塑料加工技术的行业研讨会，以及更广泛地影响塑料可持续性的教育网络研讨会。这项研究将研究新的材料加工策略，旨在用不同相对分子质量、支化结构和结晶度的聚乙烯取代传统的多层包装系统，以获得优于已知的同类最佳阻隔薄膜的性能。这些策略需要更好地理解和控制聚合物的形态，具体地说：(1)熔体塑化动力学的表征，(2)层乘超声放大，以及(3)发展结构-过程-性能相关性，以重复地从一系列聚合物链结构出发，诱导高结晶度和曲折的层次化结构。对未来加工策略的研究将为在产品设计中使用单一聚合物类型提供参考，减少整个行业使用的聚合物数量以及其他材料，如金属箔、纸层和对软包装的可回收性产生不利影响的添加剂。到项目结束时，我们的目标是：(1)论证采用层乘熔融塑化的全聚烯烃阻隔薄膜的技术可行性；(2)提供熔融塑化聚合物多层膜中聚合物和薄膜结构与工艺条件和性能之间关系的预测模型；以及(3)建立工艺能量和生命周期特征的模型。研究计划包括提高塑料可持续发展知识的教育讲习班，以及更广泛地影响塑料可持续发展的社区网络研讨会。从代表性不足的群体中招收学生，有针对性的制造业教育活动，以及扩大到当地社区进行劳动力发展培训，将丰富研究，提高其相关性，并产生切实的多样性、公平性和包容性结果。这个未来制造业奖得到了化学、生物、环境工程和运输系统部门、工程局的土木、机械和制造创新部门以及数学和物理科学局的材料研究部的共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The need for highly functional flexible packaging for food, medical products, and consumer goods is growing worldwide, but single-use plastics are also contributing to environmental pollution. Current materials are not recyclable because of their heterogeneity and related challenges in collection, separation, cleaning, and reprocessing. While chemical recycling methods are rapidly evolving, these approaches require high energy input, and the intrinsic material value is lost. This project will enable increased recycling of flexible films through creation of a manufacturing process for high performance barrier films from a single polymer type. Industrial, economic, and societal benefits respectively include: (1) enhanced functional properties in films for high volume applications, (2) cost competitiveness driven by technologies that are compatible with current processing systems, and (3) greatly enhanced plastics recycling enabled by simplified material systems. The research plan includes industry workshops for advancing the novel plastics processing technologies as well as educational webinars to impact plastics sustainability more broadly.This research will investigate new materials processing strategies designed to replace traditional multilayer packaging systems with polyethylenes of varying molecular weight, branching structures, and crystallinity to achieve properties superior to known best-in-class barrier films. These strategies require improved understanding and control of polymer morphology, specifically: (1) characterization of the melt-mastication dynamics, (2) scale-up with layer multiplying sonication, and (3) developing structure-process-property correlations to reproducibly induce high crystallinity and tortuous hierarchical structures starting from a range of polymer chain architectures. The research on future processing strategies will inform the use of single polymer types serving multiple purposes in a product design, reducing the number of polymers employed across the industry as well as other materials such as metallized foils, paper layers, and additives that adversely impact the recyclability of flexible packaging. By the end of the project, we aim to: (1) demonstrate technical feasibility of all-polyolefin barrier films using layer multiplying melt-mastication, (2) deliver a predictive model relating polymer and film structure to process conditions and performance in melt-masticated polymer multilayers, and (3) produce a model of the energy and life cycle characteristics of the process. The research plan includes educational workshops for advancing plastics sustainability knowledge, and community webinars to impact plastics sustainability more broadly. Recruitment of students from underrepresented groups, targeted manufacturing education activities, and outreach to local communities for workforce development training will enrich the research, increase its relevance, and result in tangible diversity, equity, and inclusion outcomes.This Future Manufacturing award was supported by co-funding from the Chemical, Biological, Environmental Engineering and Transport Systems Division, and the Civil, Mechanical and Manufacturing Innovation Division in the Directorate for Engineering, and the Division of Materials Research in the Directorate for Mathematical and Physical Sciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.