Controlled Fragmentation of Polyolefinic Materials triggered by Microwave Irradiation

微波辐照引发聚烯烃材料的受控断裂

• 批准号: 2134564
• 负责人: Olga Kuksenok
• 金额: $ 45.07万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2134564&HistoricalAwards=false
• 关键词: Controlled; Fragmentation; Polyolefinic; Materials; triggered

This project seeks to develop a novel strategy to convert a large class of conventional thermoplastics into materials suitable for further reuse, recycling, and upcycling. The design of materials that retain properties of conventional thermoplastics but are capable of end-of-life controlled deconstruction into reusable polymer chain fragments will be targeted. The polymer chain fragments produced by this thermal decomposition process will be used to synthesize recyclable polyesters, which in turn are expected to contribute to a circular economy, an economic system that reduces waste and avoids excessive use of resources. Polymer synthesis, materials fabrication, and multiscale modeling will be integrated in this project. The project is expected to establish guidelines for efficient design of thermoplastic materials; the ability to manufacture these materials could potentially open a novel direction in large-scale applications of recyclable components employed in the household, construction, automotive, and other sectors of the U.S. economy. The project will offer ample research and educational opportunities for graduate, undergraduate, and local high school students. Students working on this project will gain knowledge of fundamental concepts and an understanding of current challenges in materials science and sustainability. This multidisciplinary project is expected to stimulate the undergraduate and K-12 students’ interest and increase public awareness in STEM fields via gaining knowledge of the state-of-the-art polymer recycling/upcycling technologies. A strong emphasis will be placed on actively recruiting students with underrepresented backgrounds. Some of the outcomes of the research and relevant educational materials will be made available to the broad scientific community via a science and engineering gateway, nanoHUB, which is a part of the Network for Computational Nanotechnology.The objective of this research program is to develop a manufacturing strategy that enables microwave-triggered chemical upcycling of polyolefinic materials after their end-of-life. The design of polyolefinic materials (POMs) with properties of conventional polyolefins but capable of controlled deconstruction into macromolecular chain fragments with well-defined molecular weight distribution will be targeted. Functionalized nanosheets dispersed within the POMs will localize heating and trigger fragmentation upon application of short microwave pulses. Macromolecular chain fragments will be further used to synthesize recyclable semicrystalline polyesters (RPEs). Furthermore, cyclic depolymerization and repolymerization of these semicrystalline polyesters will be demonstrated. Experimental studies and computational modeling will be iteratively integrated. A multiscale model integrating coarse-grained (energy-conserving dissipative particle dynamics) and continuum approaches will be developed. Model parameters will be based on the experimental data, and model predictions will be validated with experiments. Modeling predictions will be used to understand and optimize the fragmentation process and RPE synthesis and depolymerization to achieve a targeted molecular weight distribution of chain fragments and to optimize depolymerization and repolymerization yield for the recyclable semicrystalline polyesters. The designed polyolefinic microwave-triggered fragmentation functionality will be built-in during fabrication without compromising the mechanical properties of the materials. The proposed research directly addresses current challenges by focusing on developing efficient chemical processes, improving environmental sustainability, designing tailor-made materials, and developing computer simulation approaches aiding composite material synthesis and processing. The multiscale modeling framework developed herein will account for the reactions, heat transfer, and diffusion of all the species including chain fragments, macroradicals, and low molecular weight reagents. This model, in conjunction with experimental validation, will allow one to gain a fundamental understanding of the dynamic processes taking place during controlled fragmentation and subsequent depolymerization/repolymerization cycles. The realization of the proposed program is anticipated to have a transformative impact on development of deconstructable-on-demand thermoplastics, with properties and processability of currently employed materials. Polyolefinic materials produced from plastic waste are envisioned to become an essential part of the circular economy. Undergraduate and graduate students will be trained in model and code development and in materials synthesis, fabrication, and characterization. Importantly, the students focusing on materials modeling and the students conducting experiments will interact closely within this project, so that all the students involved will gain a valuable collaborative experience and a broader perspective on their projects. A strong emphasis will be placed on supporting student diversity. Further, this project is expected to stimulate undergraduate and K-12 students’ interest in STEM fields. Selected research outcomes will be incorporated into courses taught by both PIs; related educational materials will be made available via the nanoHUB portal.This project is jointly funded by the Process Systems, Reaction Engineering, and Molecular Thermodynamics Program of ENG/CBET and the Established Program to Stimulate Competitive Research (EPSCoR),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.

该项目寻求开发一种新的策略，将一大类传统热塑性塑料转化为适合进一步重复使用、回收和升级循环的材料。目标是设计保留传统热塑性塑料性能但能够在寿命结束时受控地分解为可重复使用的聚合物链片段的材料。这种热分解过程产生的聚合物链碎片将用于合成可回收聚酯，这反过来有望促进循环经济，一种减少浪费和避免过度使用资源的经济体系。该项目将集聚合物合成、材料制造和多尺度建模于一体。该项目预计将为热塑性材料的高效设计建立指导方针；制造这些材料的能力可能会为家庭、建筑、汽车和美国经济的其他部门中使用的可回收部件的大规模应用开辟一个新的方向。该项目将为研究生、本科生和当地高中生提供充足的研究和教育机会。从事这个项目的学生将获得基本概念的知识，并了解当前材料科学和可持续发展方面的挑战。这个多学科项目预计将通过获得最先进的聚合物回收/升级技术来激发本科生和K-12学生的兴趣，并提高公众对STEM领域的认识。重点将放在积极招收背景不足的学生上。一些研究成果和相关的教育材料将通过科学和工程门户NanHUB向广大科学界提供，该门户是计算纳米技术网络的一部分。该研究计划的目标是开发一种制造战略，使聚烯烃材料在寿命结束后能够进行微波触发的化学循环。聚烯烃材料(POMS)的设计具有传统聚烯烃的性质，但能够控制解构成具有明确分子量分布的大分子链片段。分散在POMS中的功能化纳米片在施加短微波脉冲时将局部加热并触发碎裂。大分子链段将进一步用于合成可回收的半结晶聚酯(RPE)。此外，还将演示这些半结晶聚酯的循环解聚和再聚合。实验研究和计算建模将反复整合。将发展一种结合粗粒(能量守恒的耗散粒子动力学)和连续介质方法的多尺度模式。模型参数将以实验数据为基础，模型预测将通过实验进行验证。模型预测将用于了解和优化裂解过程以及RPE的合成和解聚，以实现链片段的目标分子量分布，并优化可回收半结晶聚酯的解聚和再聚合产率。设计的聚烯烃微波触发裂解功能将在制造过程中内置，而不会影响材料的机械性能。这项拟议的研究通过专注于开发高效的化学过程、改善环境可持续性、设计定制材料以及开发辅助复合材料合成和加工的计算机模拟方法，直接应对当前的挑战。本文开发的多尺度模拟框架将考虑所有物种的反应、热传递和扩散，包括链段、大分子药物和低分子试剂。该模型与实验验证相结合，将使人们能够从根本上了解在受控碎裂和随后的解聚/再聚合循环期间发生的动态过程。拟议计划的实现预计将对按需解构热塑性塑料的开发产生革命性影响，使其具有当前使用的材料的性能和加工性。从塑料垃圾中生产的聚烯烃材料有望成为循环经济的重要组成部分。本科生和研究生将接受模型和代码开发以及材料合成、制造和表征方面的培训。重要的是，专注于材料建模的学生和进行实验的学生将在这个项目中进行密切的互动，这样所有参与的学生都将获得宝贵的协作经验和对他们的项目有更广阔的视角。重点将放在支持学生多样性上。此外，该项目有望激发本科生和K-12学生对STEM领域的兴趣。选定的研究成果将被纳入两个PI教授的课程；相关教育材料将通过NanHUB门户网站提供。该项目由ENG/CBET的过程系统、反应工程和分子热力学计划以及既定的激励竞争研究计划(EPSCoR)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。