New piperidinones as material platform for reversible polymer chemistries

聚合物材料的可逆聚合和化学回收正变得越来越重要，因为塑料在废流管理和环境方面的实际辩论中所起的作用越来越重要。按需、有控制地、高效地降解聚合物材料，同时保持降解产物的高价值和高纯度，这些都是闭环系统回收战略未来成功的关键方面。这项建议涉及建立新的和通用的基于哌啶酮的多功能单体，用于线性和交联型聚合物体系，可以根据需要(pH和温度)进行降解。哌啶类化合物表现出很高的类似醛的反应活性，并与亲核剂如醇或胺发生加成反应和缩合反应，分别得到半缩醛/缩醛或半氨基/氨基。通过调整哌啶酮单体和亲核剂的反应性和官能度，聚合产物的结构、构型和稳定性以及反应的可逆性是高度可调的。由此产生的具有广泛不同性质的线性和交联型聚合物体系将被设计用于各种应用，例如可逆热固性材料、可生物降解的高玻璃化温度热塑性塑料或用于锂离子电池的固态聚电解质。对单体反应性的基础研究将伴随着单体的开发、聚合和结构表征，以建立一个新的材料平台。

Reversible polymerizations and chemical recycling of polymeric materials is becoming increasingly important for the role of plastics in the actual debate on waste stream management and environmental aspects. Degrading polymeric materials on demand, in a controlled way, with high efficiency and while retaining a high value and purity of degradation products are all key aspects to the future success of closed-loop recycling strategies. This proposal is concerned with the establishment of new and versatile piperidinone-based multifunctional monomers for linear and cross-linked polymer architectures that can be degraded on demand (pH and temperature). Piperidinones show high, aldehyde-like reactivity in addition and condensation reactions with nucleophiles such as alcohols or amines to give hemiacetals/acetals or hemiaminals/aminals, respectively. By tailoring reactivity and functionality of the piperidinone monomer as well as of the nucleophile, structure, architecture and stability of the polymeric product, as well as reversibility of the reaction is highly tunable. The resulting linear and cross-linked polymer architectures with broadly varying properties will be designed for diverse applications such as reversible thermosets, biodegradable high Tg thermoplastics or solid state polyelectrolytes for lithium ion batteries. Fundamental investigations on monomer reactivity will accompany monomer development, polymerization and structural characterization to establish piperidinones as a new material platform.