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; 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.

该项目旨在制定一种新型策略，将大量的常规热塑性塑料转换为适合进一步再利用，回收和升级的材料。将保留常规热塑性功能但能够对可重复使用的聚合物链片段的寿命末控制解构的材料设计。该热分解过程产生的聚合物链碎片将用于合成可回收的聚酯，而可回收的聚植物则有望有助于循环经济，这是一种减少废物并避免过度使用资源的经济体系。聚合物合成，材料制造和多尺度建模将集成到该项目中。预计该项目将建立有效设计热塑性材料的准则；制造这些材料的能力可能会在美国经济的家庭，建筑，汽车和其他领域的可回收组件的大规模应用中打开新的方向。该项目将为研究生，本科和当地高中生提供充足的研究和教育机会。从事该项目的学生将获得有关基本概念的知识以及对材料科学和可持续性中当前挑战的理解。预计该多学科项目将通过了解最先进的聚合物回收/升级技术来刺激本科和K-12学生的兴趣，并提高STEM领域的公众意识。强烈的重点将放在积极招募代表性不足的学生的情况下。该研究和相关教育材料的一些结果将通过纳米胡ub的科学和工程网关提供给广泛的科学界，这是计算纳米技术网络的一部分。该研究计划的目的是制定一种制造策略，以实现微波触发的化学化学化学化学化学材料，以使其在其最终的生命之后生存。具有常规聚苯乙烯的特性，但能够对具有明确定义的分子量分布的大分子链片段的特性设计进行聚油材料（POM）的设计。分散在POM中的功能化纳米片将在应用短微波脉冲时定位加热并触发碎片。大分子链碎片将进一步用于合成可回收的半稳定阶层多植物（RPE）。此外，将展示这些半稳定聚酯的环状沉积和重聚。实验研究和计算建模将进行迭代整合。将开发一个多尺度模型，该模型将开发出粗粒（能量持续的耗散粒子动力学）和连续方法。模型参数将基于实验数据，模型预测将通过实验验证。建模预测将用于理解和优化碎片化过程以及RPE合成和沉积，以实现链片段的靶向分子量分布，并优化可回收半固定碱多植物的沉积和重新聚合产率。设计的聚油微波触发的片段化功能将在制造过程中内置，而不会损害材料的机械性能。拟议的研究通过着重于开发有效的化学过程，改善环境可持续性，设计量身定制的材料以及开发计算机模拟方法来帮助复合材料的综合和加工来直接解决当前挑战。本文开发的多尺度建模框架将解释所有物种的反应，传热和扩散，包括链片段，大自由基和低分子量试剂。该模型与实验验证结合使用，将使人们能够对受控碎片和随后的沉积/重聚周期的动态过程获得基本理解。预计该计划的实现将对可消除型热塑料的开发产生变革性的影响，并具有当前使用的材料的特性和加工性。设想由塑料废物生产的聚油材料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该项目中紧密互动，以便所有参与的学生将获得宝贵的协作经验，并对他们的项目进行更广泛的观点。强烈的重点将放在支持学生多样性上。此外，该项目有望刺激本科生和K-12学生对STEM领域的兴趣。选定的研究成果将纳入PIS教授的课程中；相关的教育材料将通过纳米布门户提供。该项目由工程系统，反应工程和ENG/CBET的分子热力学计划以及启发竞争性研究的既定计划（EPSCOR）共同资助，该奖项反映了NSF的法定任务，反映了使用基金会的智力Merit和SparriT和SparriT和广泛的评估，以表彰其的法定任务。