High Selectivity and Activity Catalysts to Deliver Sustainable Polymers

聚合物是一种用途广泛的材料，在我们的日常生活中必不可少，在各个领域都有应用。现代医药、消费品、包装、建筑、纺织、电子和运输都依赖于聚合物。用于制造塑料的大部分材料来自不可持续的枯竭石化或化石燃料来源。在过去的几十年里，塑料制造业呈指数级增长，塑料的普遍存在导致了全球的严重污染。最近的研究集中在可再生或生物衍生资源(如植物提取物或二氧化碳)制成的可持续塑料上，但将机械和热性能与化石燃料衍生聚合物相匹配一直是具有挑战性的。性能可以通过制造嵌段共聚物来修改和改善，这是两个化学上不同的单体片段相互连接的地方。目前的研究主要集中在具有2个或3个嵌段的聚合物上。2014年，发现了一种新型催化剂，它可以方便地制备嵌段共聚物，对单体进行精确测序，并允许多嵌段序列。这些嵌段聚合物具有良好的性能，使用后很容易回收或生物降解，但需要进一步的性能改进。该项目致力于更好的聚合物性能和用于制造的催化。这种催化将用于比较具有不同单体序列的嵌段聚合物的性能，包括三嵌段聚酯、五嵌段聚酯和聚碳酸酯。该项目将揭示最佳制造方法、聚合物化学结构-性能关系，并评估回收选项。在第二阶段，将通过添加非常少量的富含稀土的金属离子(例如锌、镁或钙离子)来研究聚合物离聚体，以提供瞬时的链交联性和中等的性能。将对所有制造的聚合物进行强度、韧性、硬度和弹性等聚合物性能测试。还将评估通过再加工、回收和降解来结束使用寿命的选择。通过与工程部门的合作，将采用材料的建模来进一步优化机械性能。在最后部分，将通过了解动态共价相互作用(即利用可逆金属离子配位化学)来评估聚合物的自愈性能。最终，该项目旨在利用可再生资源生产具有与当前商业聚合物匹配的热和机械性能的可持续塑料。该项目属于EPSRC“制造未来”研究领域。

Polymers are highly versatile materials and essential in our everyday lives with applications in every sector. Modern medicine, consumer products, packaging, construction, textiles, electronics, and transportation are all dependant on polymers. The majority of materials used to make plastics are derived from unsustainable depleting petrochemical or fossil fuel sources. Manufacturing of plastics has increased exponentially over the past several decades, and the pervasive nature of plastic has led to intense pollution globally.Recent efforts in research have focussed on sustainable plastics made from renewable or bio-derived resources, such as plant extracts or carbon dioxide, but matching mechanical and thermal properties to fossil fuel derived polymers has been challenging. Properties can be modified and improved by making block copolymers, this is where two chemically distinct segments of monomers are attached to each other. Current research has focussed largely on polymers with either 2 or 3 block segments. In 2014, a new type of catalysis was discovered which enables facile preparation of block copolymers with precise sequencing of the monomers and allowing multi-block sequences. These block polymers had good properties and were easily recycled or biodegraded after use, however, further property improvements are required.This project addresses both better polymer properties and catalysis used in manufacturing. The catalysis will be applied to compare properties of block polymers featuring different monomer sequences, including tri-, penta- and hepta-block polyesters and polycarbonates. The project will uncover the optimum manufacturing methods, polymer chemistry structure-performance relationships, and assess recycling options. In a second phase, polymer ionomers will be investigated by addition of a very low quantity of earth-abundant metal ions (e.g. zinc, magnesium, or calcium ions) to provide transient chain cross-linking and moderate properties. Polymer properties, like strength, toughness, stiffness, and elasticity will be tested for all polymers made. The end-of-life options through re-processing, recycling, and degradation will also be assessed. Through a collaboration with the engineering department, modelling of the materials will be employed to further optimise the mechanical properties. In the final part, the self-healing properties of the polymers will be assessed by understanding dynamic covalent interactions, i.e. where reversible metal ion coordination chemistry is exploited.Ultimately, this project aims to utilize renewable resources to produce sustainable plastics with thermal and mechanical properties that match current commercial polymers. This project falls within the EPSRC 'manufacturing the future' research area.