Cyclic poly(phthalaldehyde) (cPPA) is a metastable and stimuli responsive polymer that undergoes rapid solid state depolymerization and has been utilized as a packaging and encapsulating material for transient applications. However, the early onset thermal depolymerization of cPPA severely hinders the fabrication and processing of plastic parts. Herein, the thermally triggered depolymerization of cPPA was investigated and tailored to enable thermal processing and molding of cPPA at moderate temperatures below the thermal depolymerization temperature. Stabilization of cPPA at elevated temperature was accomplished by removal of the latent Lewis acid catalyst BF₃ and by addition of radical inhibitors and a Lewis base. Addition of a plasticizer to the stabilized cPPA enabled the fabrication of a monolithic solid polymer via hot press molding. Importantly, it is shown that the thermally processed cPPA retains its stimuli responsive depolymerization capability and will enable future work in the fabrication of bulk plastic parts that depolymerize and disintegrate on demand.

中文翻译：

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环状聚（苯二甲醛）：热成型散装瞬态材料

环状聚苯二甲醛 (cPPA) 是一种亚稳态和刺激响应性聚合物，可进行快速固态解聚，已被用作瞬态应用的包装和封装材料。然而，cPPA的早期热解聚严重阻碍了塑料部件的制造和加工。在此，研究并定制了 cPPA 的热触发解聚，以使 cPPA 在低于热解聚温度的中等温度下进行热加工和成型。_{通过去除潜在的路易斯酸催化剂 BF 3}来实现 cPPA 在高温下的稳定化并通过添加自由基抑制剂和路易斯碱。在稳定的 cPPA 中添加增塑剂可以通过热压成型制造整体固体聚合物。重要的是，研究表明，热处理后的 cPPA 保留了其刺激响应解聚能力，并将在未来生产可按需解聚和分解的散装塑料部件方面成为可能。