Universal Strategy for the Synthesis of Sequenced Copolymers with Molecular Weight Control

医药、能源和电子领域的技术进步往往取决于合适材料的可用性。聚合物是由数百个单体亚基组成的长链，是许多这些领域中使用的一类重要材料。 虽然生物聚合物的性质，如蛋白质和DNA，是从序列中获得的，但制备具有受控序列的非生物聚合物的方法很少。 匹兹堡大学的塔拉迈耶教授得到了美国国家科学基金会大分子、超分子和纳米化学项目的支持，开发了一种从有序单体单元制备聚合物的新方法。 使用这种方法，可以通过有限数量的单体亚单元的重排来构建具有一系列性质的大量聚合物，例如，ABABABAB...对AABBAABB. . 本文所采用的方法提供了重要的优势，包括增加规模，控制链长，并创造更复杂的架构的潜力，几个竞争的策略。 本科和研究生教育是该项目的重要组成部分。 学生通过参与研究专门在聚合物化学方面进行培训，更普遍的是通过Meyer教授的直接指导和参加一系列研讨会来提高职业技能。 讲习班，虽然一般提供给所有感兴趣的研究生参与者，强调技能和知识，被认为是特别有帮助的学生从代表性不足的种族，性别和社会经济群体。采用具有3-12个单体的嵌入序列的大环的熵驱动开环聚合（ED-ROMP）来生产具有编码序列的周期性显示和受控分子量的聚合物。 基本ED-ROMP协议的两个新变体，选择性增强（SEED-ROMP）和失活（DED-ROMP），被开发以改善分子量控制，降低分散性并允许制备更复杂的嵌段结构。 通过研究每个过程的动力学，分子量和分散性，本研究的目的是获得更好的基本了解这些过程和信息的重要发展优化，通用协议的艾德-，SE艾德-和DED-ROMP。 这些方法适用于两个不同类别的顺序共聚物的制备：可生物降解的聚（乳酸-共-乙醇酸）和半导体共轭亚芳基乙烯基。 与每个系统的目标应用，即，生物工程和光电子学相关的性质被测量，并与起始低聚物和/或通过测序的低聚物的直接逐步生长偶联制备的共聚物的性质进行比较。

Technological advances in medicine, energy, and electronics often depend on the availability of suitable materials. Polymers, which are long chains made up of hundreds of monomer subunits, are an important class of materials employed in many of these fields. Although the properties of biological polymers, like proteins and DNA, are derived from sequence, few methods for preparing non-biological polymers with controlled sequences exist. Professor Tara Meyer of the University of Pittsburgh is supported by the Macromolecular, Supramolecular and Nanochemistry Program of NSF to develop a new method for preparing polymers from sequenced monomer units. Using this method a large number of polymers with a range of properties can be constructed by rearrangement of a limited number of monomer subunits, e.g., ABABABAB... vs. AABBAABB... . The method employed herein offers important advantages over the few competing strategies including increased scale, control of chain length, and the potential for the creation of more complex architectures. Undergraduate and graduate education is a significant component of this project. Students are trained specifically in polymer chemistry by participation in the research and more generally in career skills by direct mentoring from Prof. Meyer and through participation in a series of workshops. The workshops, although offered generally to all interested graduate student participants, stress skills and knowledge that are recognized as particularly helpful for students from underrepresented racial, gender, and socioeconomic groups. Entropy-driven ring-opening polymerization (ED-ROMP) of macrocycles with embedded sequences of 3-12 monomers is employed to produce polymers with a periodic display of the encoded sequence and controlled molecular weights. Two new variants of the fundamental ED-ROMP protocol, Selectivity Enhanced (SEED-ROMP) and Deactivation (DED-ROMP), are developed in order to improve molecular weight control, lower dispersities and allow for the preparation of more complex block architectures. By studying the kinetics, molecular weights and dispersities for each process, this research aims to gain a better fundamental understanding of these processes and information important for developing optimized, universal protocols for ED-, SEED-, and DED-ROMP. These methods are applied to the preparation of two distinct classes of sequenced copolymers: biodegradable poly(lactic-co-glycolic acid)s and semi-conducting conjugated arylene vinylenes. Properties related to the targeted application of each system, i.e, bioengineering and optoelectronics, are be measured and compared with those of the starting oligomers and/or the copolymers prepared by direct step-growth coupling of the sequenced oligomers.