New Designs for Degradable Polymers

聚合物，通常被称为塑料，在我们的日常生活中扮演着许多重要的角色。在食品包装中，它们提供物理保护，以及空气和水的屏障，同时比玻璃或金属更轻，更便宜。它们也越来越多地用于电子和医药领域。塑料的许多传统应用都依赖于其高的长期稳定性。例如，人们希望塑料包装能在数月或数年内保持其结构和性能，而用于关节置换的塑料应能在人体中存活数十年。然而，人们越来越担心塑料污染对人类和环境的影响。据预测，到2050年，将有近12000公吨的塑料堆积在垃圾填埋场和环境中。此外，对于治疗学和再生医学中聚合物的许多应用，希望聚合物能够分解，而不是在体内积累。因此，开发可降解聚合物的兴趣一直在增长。例如，在聚酯和多糖的制备和应用方面取得了重大进展。然而，这些聚合物在许多不同的环境中逐渐降解，有时比期望的更慢或更快，这阻碍了它们的广泛应用。为了更好地控制聚合物降解的时间和地点，我的研究团队一直在开发一类新的可降解聚合物，称为“自焚聚合物”（SIPs）。这些聚合物被设计成在使用过程中是稳定的，但是当受到光、热、温和的酸或其他特定化学物质等刺激时，它们会迅速降解（解聚）。它们经过化学组装，使得单个刺激事件足以降解整个聚合物链。此外，它们对刺激的反应可以很容易地通过切换聚合物末端的单个封顶分子来改变。到目前为止，sip和可访问属性的数量非常有限。在此背景下，提出的研究计划的目标是：1)开发新的SIP主干网，大大扩展可访问属性和应用的阵列。2)准备和研究新的SIP架构。聚合物链的形状通常决定聚合物的性能，但这方面的研究很少。我们将探索这一前沿。3)探索SIP表面涂层，展示SIP解决关键实际挑战的潜力，包括抗菌表面和可逆粘合剂的开发。我的研究计划的长期愿景是开发一种聚合物化学“工具箱”，它将使聚合物降解得到很好的控制，最终使可降解聚合物在许多应用中取代传统聚合物。这些工具还将为医学和其他领域的应用提供新的特性和功能。

Polymers, commonly referred to as plastics, have many important roles in our daily lives. In food packaging, they provide physical protection, as well as a barrier to air and water, while being lighter and cheaper than glass or metal. They are also increasingly used in electronics and medicine. Many traditional applications of plastics have relied on their high long-term stability. For example, it is desired that plastic packaging retains its structure and properties for months or years, while the plastic used in joint replacements should survive for decades in the human body. However, there are growing concerns about the impact of plastic pollution on humans and the environment. It is predicted that almost 12,000 metric tons of plastic will have accumulated in landfills and the environment by 2050. Furthermore, for many applications of polymers in therapeutics and regenerative medicine, it is desired that polymers break down, rather than accumulate in the body. Therefore, the interest in developing degradable polymers has been growing. For example, significant progress has been made in the preparation and application of polyesters and polysaccharides. However, these polymers degrade gradually in many different environments, sometimes more slowly or more rapidly than desired, which hinders their widespread application. To gain a new level of control over when and where polymers degrade, my research team has been developing a new class of degradable polymers termed "self-immolative polymers" (SIPs). These polymers are designed to be stable during their use, but then to degrade (depolymerize) rapidly when triggered by a stimulus such as light, heat, mild acid, or other specific chemicals. They are chemically assembled such that a single stimulus event is sufficient to degrade an entire polymer chain. In addition, the stimulus to which they respond can be easily changed by switching a single capping molecule at the end of the polymer. So far, the number of SIPs and accessible properties is very limited. In this context, the objectives of the proposed research program are to: 1)Develop new SIP backbones, greatly expanding the array of accessible properties and applications. 2)Prepare and study new SIP architectures. Polymer chain shape often determines properties, but this aspect has been investigated very little for SIPs. We will explore this frontier. 3)Explore SIP surface coatings, demonstrating the potential for SIPs to address key practical challenges, including the development of antibacterial surfaces and reversible adhesives. The long-term vision for my research program is to develop a polymer chemistry "toolbox" that will enable excellent control over polymer degradation, eventually allowing degradable polymers to replace conventional polymers in many applications. These tools will also provide new properties and functions for applications in medicine and beyond.