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.

该项目旨在开发一种新颖的策略，将一大类传统热塑性塑料转化为适合进一步再利用、回收和升级改造的材料。材料的设计保留了传统热塑性塑料的特性，但能够在使用寿命结束时进行受控解构。该热分解过程产生的聚合物链片段将用于合成可回收聚酯，从而有望促进循环经济，即减少浪费和避免过度使用的经济系统。该项目将整合聚合物合成、材料制造和多尺度建模，为热塑性材料的高效设计制定指南；制造这些材料的能力可能会为大规模应用开辟新的方向。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，帮助他们获得基础知识。概念和对当前挑战的理解这个多学科项目预计将通过了解最先进的聚合物回收/升级技术知识，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。将致力于积极招募具有代表性不足的背景的学生，一些研究成果和相关教育材料将通过科学和工程网关 nanoHUB（计算纳米技术网络的一部分）向广大科学界提供。 .本研究的目的该计划的目的是开发一种制造策略，使聚烯烃材料在其使用寿命结束后能够进行微波触发化学升级回收，设计具有传统聚烯烃特性但能够受控解构为具有良好性能的大分子链片段。将针对分散在 POM 中的功能化纳米片进行定位，并在应用短微波脉冲时触发断裂。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，并将迭代集成集成粗粒（节能耗散粒子动力学）和连续介质方法的多尺度模型。将根据实验数据制定模型参数，并通过实验验证模型预测。建模预测将用于了解和优化裂解过程以及 RPE 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。所提出的研究通过专注于开发高效的化学工艺、改善环境来直接解决当前的挑战。可持续性、设计定制材料以及开发有助于复合材料合成和加工的计算机模拟方法。本文开发的多尺度建模框架将考虑所有物质的反应、传热和扩散，包括链片段、大分子自由基和低分子。该模型与实验验证相结合，将使人们对受控碎片和随后的解聚/再聚合循环期间发生的动态过程有一个基本的了解，预计所提出的程序的实现将对产生变革性影响。开发可按需分解的热塑性塑料，其特性和可加工性与目前使用的塑料废料生产的聚烯烃材料预计将成为循环经济的重要组成部分，并将接受模型和代码开发以及相关方面的培训。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密切互动，因此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更广泛的视角。将重点放在此外，该项目预计将激发本科生和 K-12 学生对 STEM 领域的兴趣；相关的教育材料将通过 nanoHUB 门户提供。该项目由 ENG/CBET 的过程系统、反应工程和分子热力学项目以及刺激竞争研究既定项目 (EPSCoR) 共同资助，该奖项反映了 NSF 的法定使命，并具有通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。