Abstract A series of linear segmented poly(urethane acyl- semicarbazides) of different compositions were synthesized from polypropylene glycol (M n ∼ 1000 and 2000), hexamethylene diisocyanate and cyclohexanedicarboxylic acid 1,4 dihydrazide. The polymers exhibited thermoreversible gelation at a minimum gelation concentration of 25 mg/mL in DMSO in about 25 min. Among the comparisons of varying NCO/OH ratios, PPG 1000 based polyurethanes with NCO/OH ∼ 2.5 and 3 and PPG 2000 based systems with NCO/OH ∼ 3.0 and 3.5 exhibited gelation. IR studies on the solutions and gels (in DMSO) revealed the extensive H-bonding between the chains in gel state. Scanning electron micrographs of the xerogel revealed a 3D-network structure – higher hard segment content (P 1000 -1:3.5) led to a fibrous morphology and lower hard segment content (P 2000 -1:3) led to a microsphere like architecture. The phase separation induced gelation mechanism of self-assembly and effect of the stoichiometry on the morphology were explained based on the correlation between DSC, WAXS and FE-SEM data. The xerogels of the self-assembled polymers described in this work demonstrate a remarkable ability to remove dye molecules selectively, rapidly and efficiently. The gels retain their original structure and performance even after they are recycled 20 times which was quantified by UV–vis studies.

中文翻译：

---

带有脂环族基团的聚（氨基甲酸酯酰基-氨基脲）的热可逆凝胶化和废水中染料的选择性吸附研究

摘要 由聚丙二醇（Mn ∼ 1000 和 2000）、六亚甲基二异氰酸酯和环己烷二甲酸 1,4 二酰肼合成了一系列不同组成的线性链段聚（氨基甲酸酯酰基氨基脲）。聚合物在 DMSO 中的最小凝胶浓度为 25 mg/mL 时在约 25 分钟内表现出热可逆凝胶化。在不同 NCO/OH 比率的比较中，NCO/OH 约 2.5 和 3 的 PPG 1000 基聚氨酯和 NCO/OH 约 3.0 和 3.5 的 PPG 2000 基聚氨酯表现出凝胶化。对溶液和凝胶（在 DMSO 中）的 IR 研究揭示了凝胶状态下链之间的广泛 H 键合。干凝胶的扫描电子显微照片显示出 3D 网络结构——较高的硬段含量 (P 1000 -1:3.5) 导致纤维形态和较低的硬段含量 (P 2000 -1: 3）导致微球状结构。基于DSC、WAXS和FE-SEM数据之间的相关性解释了自组装的相分离诱导的凝胶化机制和化学计量对形态的影响。这项工作中描述的自组装聚合物的干凝胶表现出显着的选择性、快速和有效去除染料分子的能力。即使经过 UV-vis 研究量化的凝胶回收 20 次后，它们仍能保持其原始结构和性能。这项工作中描述的自组装聚合物的干凝胶表现出显着的选择性、快速和有效去除染料分子的能力。即使经过 UV-vis 研究量化的凝胶回收 20 次后，它们仍能保持其原始结构和性能。这项工作中描述的自组装聚合物的干凝胶表现出显着的选择性、快速和有效去除染料分子的能力。即使经过 UV-vis 研究量化的凝胶回收 20 次后，它们仍能保持其原始结构和性能。