New piperidinones as material platform for reversible polymer chemistries

聚合物材料的可逆聚合和化学回收对于塑料在废物流管理和环境方面的实际辩论中的作用变得越来越重要。按需、有控制地、高效率地降解高分子材料，同时保持降解产物的高价值和纯度，都是闭环回收战略未来成功的关键方面。该提案涉及建立新的多功能胡椒吡啶酮基多功能单体，用于线性和交联聚合物结构，可以根据需要（pH和温度）降解。哌啶酮在与亲核试剂如醇或胺的加成反应和缩合反应中表现出高的类醛反应活性，分别生成半缩醛/缩醛或半缩醛/缩醛。通过调整哌啶酮单体以及亲核试剂的反应活性和功能，聚合物产物的结构、结构和稳定性以及反应的可逆性都是高度可调的。由此产生的线性和交联聚合物结构具有广泛不同的性能，将被设计用于不同的应用，如可逆热固性，可生物降解的高Tg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单体的开发、聚合和结构表征，以建立哌啶酮作为新的材料平台。

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.