Controlled radical polymerization: from new metal mediators to novel polymer frameworks

本提案将开发具有经济重要性的可持续材料，使用对财政和环境负责的介质来控制聚合过程。我们的专长在于控制自由基聚合，特别是使用钒基配合物来控制醋酸乙烯基塑料的生产，使用铝配合物来控制具有独特宏观和微观结构的可生物降解塑料的取向。在这种情况下，宏观结构指的是像刷子、星形和梳子这样的分子框架，而微观结构指的是聚合物链中单元的相对分子取向。利用这些专业知识，我们正在两个领域追求变革目标。第一个项目将扩大我们在可控自由基聚合方面的工作，并(a)产生寿命更长、热性能更好、可调范围更广的催化剂，(b)扩大单体的范围，包括可再生脂肪酸，(c)产生具有独特性能的宏观结构，作为增值材料。第二步将宏观结构和微观结构控制结合到大分子结构的合成中。我们将生产具有潜在应用于药物递送和纳米技术的聚（乙烯醇）/聚（乳酸）聚合物刷，扩展我们在可再生丙交酯单体开环聚合的立体选择催化剂方面的工作，并制备聚（乙烯醇）嵌段共聚物作为两亲性材料，可以自组装成包括胶束在内的特定结构。一个关键的目标是通过温和的水解路线或可切换的可逆加成-破碎-转移（RAFT）介质制备聚乙烯醇共聚物。我们提出的研究将在短期内对高分子化学领域产生深远的影响，并将产生新的大分子，在生物医学、制药和材料技术领域具有潜在的应用前景。在发展创新科学的同时，我们也将培养本科生和研究生成为加拿大未来科学发展的领导者。

This proposal will develop sustainable materials of economic importance using fiscally and environmentally responsible mediators to control the polymerization process. Our expertise lies in the control of radical polymerizations, specifically the use of vanadium-based complexes to control the production of vinyl acetate based plastics and the use of aluminum complexes to control the orientation of biodegradable plastics with unique macro- and micro-structures. In this context, macrostructures refer to molecular frameworks like brushes, stars and combs while microstructure refers to the relative molecular orientation of the units in our polymer chains. From this expertise we are pursuing transformative goals in two areas. The first will expand our work on controlled radical polymerizations and (a) generate improved catalysts with longer lifetimes, better thermal properties and tunable scope, (b) expand the range of monomers to include renewable fatty acids and (c) generate macrostructures with unique properties as value-added materials. The second will incorporate both macrostructure and microstructure control into the synthesis of macromolecular structures. We will generate poly(vinyl alcohol)/poly(lactic acid) polymer brushes with potential applications in drug delivery and nanotechnology, expand our work on stereoselective catalysts for the ring-opening polymerization of renewable lactide monomers and prepare poly(vinyl alcohol) block copolymers as amphiphilic materials that will self assemble into defined structures including micelles. A key target is the preparation of poly(vinyl alcohol) copolymers through either a mild hydrolysis route or a switchable reversible-addition-fragmentation-transfer (RAFT) mediator. The research we propose will have a profound impact on the polymer chemistry community in the short term and will also produce new-to-the-world macromolecules with potential applications in biomedical, pharmaceutical and materials technology fields. Along with developing innovative science we will also be training undergraduate and graduate students to be leaders for the future of Canadian scientific advancement.