CAREER: Synthesis of Hierarchically Structured Polymeric Materials Enabled by Polymerization-Induced Branching

聚合物在我们的日常生活中有着广泛的应用。具有支化结构的聚合物，而不是直链的聚合物，产生了独特的性能，这对它们在广泛的应用中的应用至关重要。虽然已经开发了合成方法来制备带有支化的聚合物，但控制它们的支化位置和支化数量仍然具有挑战性。在这项由化学系高分子、超分子和纳米化学计划资助的项目中，耶鲁大学钟明江教授开发了一种新的方法来合成具有明确和理想的支化结构的聚合物。这些基础性发现可能会对下一代应用产生更广泛的技术影响，包括用于细胞和组织工程(人类健康)的基质，用于水处理(环境可持续性)的膜材料，以及光刻(半导体工业)。参加该项目的学生将接受合成和物理化学以及聚合物科学和工程方面的培训。钟教授教授一门新课程，这是耶鲁大学开设的第一门聚合物科学课程。研究团队接待了来自几个不同州(康涅狄格州、纽约州、罗德岛州和马萨诸塞州)的高中暑期实习生和教师，使学生能够向榜样学习科学的重要性。最后，通过保持与工业界的关系，这项研究的结果被传播到广泛的科学和技术界。该研究小组正在开发一种定点引发的可控/活性超支化聚合(CLHP)，通过合理设计新型单体，即与引发剂基团相连的单体，生产具有定制结构和高活性的HPS。在共聚条件下，HPS的支化度和化学性质都得到了很好的调节。特定位置的引发使HP基序能够精确地结合到其他材料中以合成层次化的支化结构，从而提供了对支化聚合物结构-性质关系的全面了解。研究活动包括：链生长型CLHP的开发；CLHP条件的优化以提高活性和控制质量；以及设计和合成具有目标性质的高阶含HP的高分子结构。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Polymers have a wide range of applications in our daily life. Polymers with branched structures, instead of linear chains, give rise to unique properties that are critical for their utility in a broad spectrum of applications. While synthetic methods have been developed to prepare polymers with branches, controlling where they are branched sites and the number of branches remains challenging. In this project funded by the Macromolecular, Supramolecular, and Nanochemistry Program of the Chemistry Division, Professor Mingjiang Zhong of Yale University develops a novel approach to synthesizing polymers with well-defined and desirable branching structures. The fundamental discoveries may have a broader technological impact on next-generation applications, including matrices for cellular and tissue engineering (human health), membrane materials for water treatment (environmental sustainability), and photolithography (semiconductor industry). Students participating in this program are trained in synthetic and physical chemistry, as well as polymer science and engineering. Professor Zhong teaches a new course, the first one in polymer science at Yale. The research team hosts high school summer interns and teachers from several different states (Connecticut, New York Rhode Island and Massachusetts) enabling students to learn from role models about the importance of science. Finally, by maintaining relationships with industry, the results of this research are disseminated to a broad scientific and technical community. The research team is developing a site-specifically initiated controlled/living hyperbranching polymerization (CLHP) for the production of HPs with tailored structures and high livingness through the rational design of novel inimers, i.e., monomers tethered with an initiator group. The degree of branching as well as the chemical nature of HPs is well-tuned under copolymerization conditions. The site-specific initiation enables the precise incorporation of HP motifs into other materials to synthesize hierarchically branched structures, providing a comprehensive understanding of structure-property relationships in branched polymers. The research activities include: the development of chain-growth type CLHP; the optimization of CLHP conditions to improve livingness and quality of control; and the design and synthesis of higher-order HP-containing macromolecular architectures with target 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.