Macromolecular Metamorphosis: Transformable Polymeric Materials

高分子变形：可变形高分子材料

• 批准号: 1606410
• 负责人: Brent Sumerlin
• 金额: $ 38.91万
• 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: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1606410&HistoricalAwards=false
• 关键词: Macromolecular; Metamorphosis; Transformable; Polymeric; Materials

NON-TECHNICAL SUMMARY:This project seeks to develop a new paradigm in the area of materials science by considering the effects of transformable molecular shape on final materials properties. The architecture of a polymer molecule directly affects the properties of the materials they are used to prepare. Polymers are designed to have a characteristic and static molecular structure selected for a specific application. This project involves the development and investigation of polymers composed of reversible bonds that enable dramatic transformations in their architecture when triggered. This concept introduces a new paradigm in the field of responsive polymeric materials. The resulting polymers will be structurally robust while also allowing themselves to be healed when damaged. Applications of stimuli-responsive materials are continually being developed, with significant promise having been demonstrated in the area of drug delivery, smart coatings, and self-healing materials. Polymers that undergo architectural transformations in solution may have potential utility as additives in motor oil or personal care products. Materials that demonstrate self-healing and recyclability before being fixed at elevated temperatures could address one of the fundamental limitations of many materials constructed via reversible linkages, namely their propensity to slowly deform over time. The project also includes outreach and education activities directed toward local K-12 students and training of graduate and undergraduate students in emerging areas of chemistry and polymer science.TECHNICAL SUMMARY:Currently, most examples of stimuli-responsive polymers derive their response from changes in molecular size through alterations of chain conformation or changes in polymer-solvent or polymer-polymer interactions. However, the fundamental characteristic of molecular architecture has not typically been considered a variable because a macromolecule's topology is "locked" by its covalent primary structure. This project challenges this convention by investigating materials that transform their covalent architecture when triggered by an external stimulus. By preparing polymers capable of exchanging irreversible bonds for reversible bonds, a new class of responsive materials that adapt to their surroundings by transitions in their covalent architecture can be achieved. Specifically, three systems are being considered: (1) macromolecules capable of topological transformations in solution; (2) adaptable organogels that modify their covalent structure; and (3) transformable bulk materials with "switchable" crosslinks. The first system involves polymers with complex chain architectures that irreversibly transform into new architectures when triggered. The second and third systems involve reversibly-crosslinked polymer networks that are structurally-dynamic, meaning they can be triggered to significantly rearrange their internal structure to become irreversibly crosslinked (i.e., "fixed"). These three areas have been chosen to investigate the potential of this approach across a wide spectrum of sizes (nano to macro) and material states (solution, gels, and bulk) and to dramatically expand the definition of stimuli-responsive materials.

非技术摘要：该项目旨在通过考虑可转化的分子形状对最终材料特性的影响，在材料科学领域开发新的范式。聚合物分子的结构直接影响用于制备的材料的性质。聚合物的设计为选择用于特定应用的特征和静态分子结构。该项目涉及对由可逆债券组成的聚合物的开发和调查，这些聚合物在触发时能够在其建筑中进行巨大变化。这个概念在响应式聚合物材料领域引入了新的范式。所得的聚合物在结构上将是稳健的，同时还可以在损坏时治愈自己。刺激响应材料的应用不断开发，在药物输送，智能涂料和自我修复材料领域证明了巨大的希望。在解决方案中进行建筑转换的聚合物可能具有潜在的效用作为机油或个人护理产品的添加剂。在固定在升高温度之前的材料可以证明自我修复和可回收性，这可以解决许多通过可逆链接构建的许多材料的基本局限性之一，即它们随着时间的推移而逐渐变形的倾向。 The project also includes outreach and education activities directed toward local K-12 students and training of graduate and undergraduate students in emerging areas of chemistry and polymer science.TECHNICAL SUMMARY:Currently, most examples of stimuli-responsive polymers derive their response from changes in molecular size through alterations of chain conformation or changes in polymer-solvent or polymer-polymer interactions.但是，分子结构的基本特征通常不被视为变量，因为大分子的拓扑被其共价初级结构“锁定”。该项目通过调查由外部刺激触发时改变其共价架构的材料来挑战这项公约。通过准备能够将不可逆键交换为可逆债券的聚合物，可以实现一种新的响应材料，可以通过其共价架构中的过渡来适应其周围环境。具体而言，正在考虑三个系统：（1）能够在溶液中进行拓扑转换的大分子； （2）修饰其共价结构的适应性有机凝胶； （3）具有“可切换”交联的可转换散装材料。第一个系统涉及具有复杂链体系结构的聚合物，这些聚合物在触发时不可逆转地转化为新体系结构。第二和第三个系统涉及在结构上具有可逆性的聚合物网络，这意味着可以触发它们以显着重新安排其内部结构，以使其内部结构变得不可逆转地交联（即“固定”）。已经选择了这三个区域来研究这种方法在各种大小（纳米至宏）和材料状态（溶液，凝胶和散装）中的潜力，并显着扩大了刺激反应性材料的定义。