Reshaping Recyclable Thermosets

重塑可回收热固性材料

• 批准号: 1904631
• 负责人: Brent Sumerlin
• 金额: $ 39.96万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1904631&HistoricalAwards=false
• 关键词: Reshaping; Recyclable; Thermosets

NON-TECHNICAL SUMMARYThe long-term persistence of many synthetic materials and the resulting impact on the environment has made clear the importance of developing new routes to sustainable polymers. This project aims to address the challenges of sustainability via the design of new, robust materials with longer life spans that need to be replaced less frequently. Recyclable and self-repairing materials offer one route for extending the useful lifetime of a polymeric material. Unfortunately, many of the most commonly encountered polymers that are readily recyclable and repairable suffer from poor resistance to solvents or exposure to high temperatures. Conversely, polymers with enhanced solvent, thermal, and dimensional stability are generally not recyclable and cannot be rendered self-healing, because their molecular structure does not allow the mobility required to do so. This project aims to elucidate the fundamentals that will allow bridging the divide between these two classically disparate families of materials. By exercising precise control over key molecular-scale parameters, the factors governing processability, recyclability, self-healing, and utility will be determined to allow the design of next-generation materials. A key component of this project involves outreach and educational activities directed toward local K-12 students as well as training and professional development of graduate and undergraduate students in emerging areas of chemistry and polymer science.TECHNICAL SUMMARYOne of the traditional classification mechanisms for bulk polymeric materials relies on whether or not the chains that comprise the material are crosslinked. Crosslinked polymers (i.e., thermosets) may have significantly enhanced dimensional, chemical, mechanical, and solvent stability compared to their non-crosslinked analogs (i.e., thermoplastics), but these attributes are accompanied by an inability to be reshaped or recycled. There is a significant need for materials that combine the properties of thermosets and thermoplastics by relying on reversible crosslinks that can undergo exchange by either an associative or dissociative mechanism. The former method of crosslink exchange is particularly promising because it allows for network rearrangement without loss of connectivity (i.e., no change in crosslink density). Networks that undergo associative exchange have recently become known as "vitrimers." The goal of this project is the investigation and development of vitrimers that are accessible via a straightforward method that relies on the curing of vinyl monomer-derived prepolymers generated by controlled radical polymerization. Critically, this strategy decouples the network curing and backbone polymerization steps, allowing for precise manipulation of structure, topology, and functionality within the chains comprising the network. Three specific aims will be pursued to (1) interrogate the effect of structural elements of both the polymeric and crosslinker components of vitrimers derived from vinyl polymers, (2) determine the role of chain microstructure and topology on vitrimer (re)processability, and (3) prepare and investigate vitrimers with stimuli-activatable intrinsic catalysts. Successful completion of these aims will reveal fundamental structure-property relationships of dynamically crosslinked networks while generating design principles for vitrimers with unprecedented chemical and mechanical properties..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.

非技术总结，许多合成材料的长期持久性以及对环境的影响已经明确了开发新途径至可持续聚合物的重要性。该项目旨在通过设计新的，强大的寿命跨度的新材料来应对可持续性的挑战，而寿命较长，需要更频繁地更换。可回收和自我修复材料为延长聚合物材料的有用寿命提供了一条途径。不幸的是，许多最常见的聚合物很容易回收，可修复的聚合物对溶剂的抵抗力不佳或暴露于高温。相反，具有增强溶剂，热稳定性和尺寸稳定性的聚合物通常不可回收，并且无法进行自我修复，因为它们的分子结构不允许这样做所需的迁移率。该项目旨在阐明允许弥合这两个经典材料家族之间的鸿沟的基本面。通过对关键分子尺度参数进行精确控制，将确定控制加工性，可回收性，自我修复和实用程序的因素，以允许设计下一代材料。该项目的关键组成部分涉及针对本地K-12学生的外展和教育活动，以及在化学和聚合物科学新兴领域的研究生和本科生的培训和专业发展。用于批量聚合物材料的传统分类机制的技术总结源于材料的链条是否涉及材料的链条。与非交联类似物（即热塑料）相比，交联聚合物（即热固剂）的尺寸，化学，机械和溶剂稳定性可能显着增强，但这些属性伴随着无法重塑或再生或再循环或再搭扣。通过依靠可逆交联，可以通过联想或解离机制进行交换来结合热固体和热塑性塑料的特性。以前的交联交换方法特别有希望，因为它允许网络重排而不会丧失连接​​性（即，交联密度没有变化）。进行关联交流的网络最近被称为“玻璃二聚体”。该项目的目的是通过直接方法进行研究和开发玻璃二聚体，该方法依赖于由受控的自由基聚合产生的乙烯基单体衍生的前聚合物的固化。至关重要的是，该策略将网络固化和骨干聚合步骤取消，从而可以精确地操纵包括网络的链中的结构，拓扑和功能。 （1）询问衍生自乙烯基聚合物的玻璃聚聚聚聚聚；这些目标的成功完成将揭示动态交联的网络的基本结构 - 性关系关系，同时为具有前所未有的化学和机械性能的玻璃体生成设计原理。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子和更广泛影响的评估来评估Criteria通过评估的支持。

项目成果

In situ monitoring of PISA morphologies

• DOI: 10.1039/d1py00239b
• 发表时间: 2021-07
• 期刊: Polymer Chemistry
• 影响因子: 4.6
• 作者: Julia Y. Rho;G. Scheutz;Satu Häkkinen;John B. Garrison;Qiao Song;Jie Yang;Robert Richardson;S. Perrier;B. Sumerlin

Macromolecular Photocatalyst for Synthesis and Purification of Protein–Polymer Conjugates

• DOI: 10.1021/acs.macromol.1c00508
• 发表时间: 2021-05
• 期刊: Macromolecules
• 影响因子: 5.5
• 作者: Rebecca A. Olson;Jordan S. Levi;G. Scheutz;Jacob J. Lessard;C. A. Figg;M. Kamat;K. Basso;B. Sumerlin

Photoinduced SET to access olefin-acrylate copolymers

• DOI: 10.1039/d1py01643a
• 发表时间: 2022-01-13
• 期刊: POLYMER CHEMISTRY
• 影响因子: 4.6
• 作者: Garrison, John B.;Hughes, Rhys W.;Sumerlin, Brent S.
• 通讯作者: Sumerlin, Brent S.

Excitation Dependence in Photoiniferter Polymerization

• DOI: 10.1021/acsmacrolett.2c00683
• 发表时间: 2022-12-19
• 期刊: ACS MACRO LETTERS
• 影响因子: 7.015
• 作者: Hughes, Rhys W.;Lott, Megan E.;Sumerlin, Brent S.
• 通讯作者: Sumerlin, Brent S.

Block Copolymer Vitrimers

• DOI: 10.1021/jacs.9b10360
• 发表时间: 2020-01-08
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: Lessard, Jacob J.;Scheutz, Georg M.;Sumerlin, Brent S.
• 通讯作者: Sumerlin, Brent S.