The development of healable polymers is crucial for the maintenance of underground pipeline systems during trenchless rehabilitation. While photocurable resins are commercial materials for this purpose, we introduce an innovative option: azobenzene-containing polymers (azopolymers) with photoinduced reversible solid-to-liquid transitions. The newly developed azopolymer comprises a methacrylate backbone and side chains incorporating hexyl spacers, azobenzene moieties, and dodecyl tails. We compared the thermal stability, efficiency of photoinduced solid-to-liquid transition, and adhesive strength among azopolymers with varying molecular weights. Subsequently, we identified the most suitable azopolymer for PVC pipe lining. The robust trans azopolymer inner layer maintains a solid state at ambient temperatures. Upon pipe damage, UV irradiation triggers trans-to-cis isomerization, leading to the conversion of the solid trans azopolymer into a liquid cis state. This flowing cis azopolymer effectively repairs cracks and can be reverted to its trans isomer via visible light irradiation or thermal relaxation. Unlike commercial photocurable resins, the developed azopolymers offer the advantage of multiple repair cycles. This study highlights the potential of azopolymers with photoinduced reversible solid-to-liquid transitions as innovative healable materials in trenchless rehabilitation technology.

可修复聚合物的开发对于非开挖修复过程中地下管道系统的维护至关重要。虽然光固化树脂是用于此目的的商业材料，但我们引入了一种创新选择：具有光诱导可逆固液转变的含偶氮苯聚合物（偶氮聚合物）。新开发的偶氮聚合物包含甲基丙烯酸酯主链和包含己基间隔基、偶氮苯部分和十二烷基尾部的侧链。我们比较了不同分子量的偶氮聚合物的热稳定性、光致固液转变效率和粘合强度。随后，我们确定了最适合 PVC 管道内衬的偶氮聚合物。坚固的反式偶氮聚合物内层在环境温度下保持固态。管道损坏后，紫外线照射会引发反式异构化为顺式异构化，导致固体反式偶氮聚合物转化为液体顺式状态。这种流动的顺式偶氮聚合物可有效修复裂纹，并可通过可见光照射或热弛豫恢复其反式异构体。与商业光固化树脂不同，所开发的偶氮聚合物具有多次修复周期的优点。这项研究强调了具有光诱导可逆固液转变的偶氮聚合物作为非开挖修复技术中创新可修复材料的潜力。