Developing bio-based non-isocyanate polyurethanes (NIPUs) to replace petroleum-based conventional polyurethanes (PUs) plays an essential role in green production and relieving energy pressure. However, the synthesis of NIPUs using renewable resources, and recycling after reaching service time remain to be solved. Herein, a novel structural cross-linked NIPU network with closed-loop recyclability was prepared, which is derived from abundant lignin-derived and carbon dioxide (CO₂) resources. The obtained NIPUs with dual dynamic covalent bonds exhibit relatively low activation energy (70.34 kJ/mol) and remarkable remolding efficiency (∼100 %). Importantly, spiro bi-acetal structures in polymer chains impart closed-loop recyclability to the obtained NIPUs. The results showed that they can be degraded at room temperature followed by regeneration with nearly full recovery of properties. Moreover, bio-based NIPUs are used as supporting materials to produce phase change materials (PCMs) for the first time, and the latent heat reaches 128.2 J/g. The material has favorable form stability and is leakage-proof owing to Zn^Ⅱ-carboxylates coordination interactions and stable cross-linked networks. This study demonstrates a method for the synthesis of closed-loop recyclable NIPUs from renewable resources, enriching synthetic diversity while providing an initial exploration of its potential as PCMs.

开发生物基非异氰酸酯聚氨酯（NIPU）替代石油基传统聚氨酯（PU）对于绿色生产、缓解能源压力具有重要作用。然而，利用可再生资源合成NIPU以及达到使用期限后的回收仍有待解决。在此，制备了一种具有闭环可回收性的新型结构交联NIPU网络，该网络源自丰富的木质素衍生物和二氧化碳（CO ₂） 资源。所获得的具有双动态共价键的NIPU表现出相对较低的活化能（70.34 kJ/mol）和显着的重塑效率（∼100%）。重要的是，聚合物链中的螺双缩醛结构赋予所获得的 NIPU 闭环可回收性。结果表明，它们可以在室温下降解，然后再生，性能几乎完全恢复。此外，首次采用生物基NIPU作为支撑材料制备相变材料（PCM），潜热达到128.2 J/g。该材料具有良好的形状稳定性，并且由于Zn ^{Ⅱ而防渗漏}-羧酸盐协调相互作用和稳定的交联网络。本研究展示了一种从可再生资源合成闭环可回收NIPU的方法，丰富了合成多样性，同时初步探索了其作为相变材料的潜力。