Sustainable Process Design for Catalytic Polymerization to In-Chain Functionalized Polyethylenes

就产量而言，聚乙烯是世界上生产最广泛的塑料，用于许多关键技术领域。在对环境的影响方面，其生产效率优于大多数其他塑料。聚乙烯的直链碳氢链(HDPE、LLDPE…)实现晶态填充，并提供优异的机械性能。可以通过催化剂和/或工艺条件来改变PES的(微)结构，以获得不同水平的结晶度。然而，它们的化学惰性导致在释放到环境中时会持续数十年。我们发现，通过催化乙烯和一氧化碳共聚，在大分子链上生成随机分布的酮基，有可能提高PE的(光)降解性，从而改善这些材料的可回收性。更重要的是，在不影响酮-PE材料的力学性能和加工性能的情况下，可以获得增强的光降解能力。气相聚合可以被认为是产生半结晶聚合物的最先进的工艺，因为它是无溶剂的，并且能够直接控制所产生的聚合物颗粒的形态。乙烯与极性单体的共聚一般以溶液聚合为主，但对气相聚合的研究较少。该项目将研究乙烯和一氧化碳的气相共聚合，这是一个高度相关的反应，也是一个特别适合极性单体共聚的探针，追求以下目标：-将探索通过非共价结合到多孔载体材料上的新型CO相容(无共催化剂)分子聚合催化剂的负载方法(英国康斯坦茨大学)。-探索无溶剂气相共聚合中酮-聚乙烯粒子的催化剂，解决支持裂解和形态控制等问题(催化聚合过程材料，CP2M)。-了解极性单体共聚的催化活性物种与载体之间的基本相互作用，以及载体和气相条件对催化剂行为的影响(CP2M和UKon)。-研究源于气相聚合的酮基聚乙烯的光降解性/可回收性和加工性/机械性能。这种协同合作得益于CP2M在气相聚合过程中的独特专业知识，以及康斯坦茨集团在官能团容限聚合催化剂方面的独特专业知识。

Polyethylene is the mostly widely produced plastic in the world in terms of volume, used in many key technology areas. Its production efficiency is superior to that of most other plastics in terms of envi-ronmental impact. The linear hydrocarbon chains of polyethylenes (HDPE, LLDPE…) enable crystalline packing and provide excellent mechanical properties. The (micro)structures of PEs can be modified via a catalyst and/or the process conditions to obtain different levels of crystallinity. However, their chemically inert nature results in persistence for many decades when released to the environment. We have found a promising possibility to enhance the (photo)degradability of PE, and thus to improve the recyclability of these materials, by catalytically copolymerizing ethylene with carbon monoxide to generate a random distribution of keto-groups in the macromolecular chains. What’s more, enhanced photodegradability can be obtained without compromising the mechanical properties and processibility of the keto-PE materials. Gas phase polymerization can be considered the most advanced process for the generation of semi-crystalline polymers as it is solvent-free and enables a direct control of the resulting polymer particle morphology. Copolymerization of ethylene with polar monomers in general have been studied in solution polymerizations primarily, however, and gas phase polymerization has been neglected. This project will study the gas phase copolymerization of ethylene with carbon monoxide, which is a highly relevant reaction and also a particularly suited probe for copolymerizations of polar monomers, pursuing the following objectives: - Supporting methods for novel CO-compatible (cocatalyst-free) molecular polymerization catalysts by means of non-covalent binding to porous support materials will be explored (University of Konstanz, UKon). - Exploration of these catalysts in solvent-free gas phase copolymerizations to keto-polyethylenes particles, addressing amongst others support fragmentation and morphology control (Catalysis Polymerization Processes Materials, CP2M). - Understanding of the fundamental interactions between the catalytically active species of polar monomer copolymerization and the support, and resulting effect of support and gas phase conditions on the catalysts' behaviour (CP2M&UKon). - Investigation of photodegradability/recyclability and processibility/mechanical properties of keto-polyethylenes originating from gas phase polymerization (UKon). This synergistic collaboration is enabled by the unique expertise of CP2M in gas phase polymerization process, and of the Konstanz group in functional group-tolerant polymerization catalysts.