Due to its hydroxyl terminal groups, Poloxamer^® 407 (P407), a commercially available poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer can be used as macrodiol for the synthesis of high molecular weight amphiphilic poly(ether urethane)s (PEUs). This work was aimed at studying the effect of P407 purification by removing PEO-PPO diblock copolymer by-products on the chemical properties of PEU polymer and the physical properties of PEU hydrogels. Removal of PEO-PPO diblock copolymers (P407_P) was found to preserve the thermo-responsiveness of resulting hydrogels, although slightly lower gelation onset temperature (T_onset) was found for P407_P (15.3°C) vs. P407 (16.7°C) hydrogels (25% w/V) as assessed through temperature ramp test. P407 and P407_P were then reacted with 1,6-diisocyanatohexane and 1,4-cyclohexanedimethanol to synthesize two different PEUs, coded as CHP407 and CHP407_P, respectively. Lower Number Average Molecular Weight (Mn¯) and higher polydispersity Index (D) was measured for CHP407 (Mn¯: 34 kDa, D: 1.6) respect to CHP407_P (Mn¯: 40 kDa, D: 1.4) as a consequence of macrodiol purification. CHP407_P hydrogels formed bigger micelles (43.9 ± 4.1 nm vs. 28.7 ± 4 nm) while showed similar critical micellar temperatures (22.1°C vs. 21.6°C) respect to CHP407 formulations. Sol-to-gel transition of CHP407 and CHP407_P hydrogels was similar while CHP407_P gelation time at 37°C was longer as assessed by tube inverting test. The rheological analysis showed slightly lower T_onset for CHP407_P hydrogels (15% w/V), probably due to larger micelle size, promoting micellar assembly. However, CHP407_P hydrogels showed a significantly lower critical strain than CHP407 hydrogels, as assessed by strain sweep test, suggesting their higher brittleness due to a lower density of intermicellar bridge chains. Nano-scale hydrogel characterization by Low-Field Nuclear Magnetic Resonance spectroscopy supported previous findings, showing lower spin-spin relaxation time (i.e., 1,259 ms) for CHP407_P than for CHP407 hydrogels (i.e., 1,560 ms) at 37°C, which suggested the formation of a more tightly packed network for CHP407_P than CHP407 hydrogel. Finally, lower swelling capability and resistance against dissolution were measured for CHP407_P hydrogels. Overall, the here‐reported results suggested that the heterogeneous structure in the CHP407 hydrogel network caused by the presence of diblock copolymer-based macrodiols improved PEU hydrogel properties in light of their applicability in the biomedical field.

由于它的羟基末端基团，泊洛沙姆^® 407（P407），可商购的聚（环氧乙烷） -聚（氧化丙烯） -聚（环氧乙烷）（PEO-PPO-PEO）三嵌段共聚物可被用作大分子二醇的合成高分子量两亲性聚醚氨基甲酸酯（PEUs）。这项工作旨在研究通过除去PEO-PPO二嵌段共聚物副产物对PEU聚合物的化学性质和PEU水凝胶的物理性质进行P407纯化的效果。PEO-PPO嵌段共聚物的去除（P407_P）被发现保持所得水凝胶的热响应性，虽然稍低凝胶化起始温度（T_起始）被发现为P407_P（15.3℃）与。通过温度斜坡测试评估的P407（16.7°C）水凝胶（25％w / V）。然后使P407和P407_P与1,6-二异氰酸根合己烷和1,4-环己烷二甲醇反应，合成两种不同的PEU，分别编码为CHP407和CHP407_P。较低的平均分子量（中号ñ¯）和更高的多分散指数（D）对于CHP407（中号ñ¯：34 kDa，D：1.6）相对于CHP407_P（中号ñ¯：40 kDa，D：1.4）是大分子二醇纯化的结果。CHP407_P水凝胶形成较大的胶束（43.9±4.1 nm与。28.7±4 nm）的临界胶束温度（22.1°C）与。相对于CHP407配方为21.6°C）。CHP407和CHP407_P水凝胶的溶胶-凝胶转变相似，而37°C下的CHP407_P凝胶化时间则通过试管倒置试验评估而更长。流变分析表明T_起始值略低CHP407_P水凝胶（15％w / V），可能是由于较大的胶束尺寸，促进了胶束组装。然而，通过应变扫描测试评估，CHP407_P水凝胶显示出比CHP407水凝胶显着更低的临界应变，这表明它们的高脆性是由于较低的胶束间桥链密度所致。通过低场核磁共振波谱对纳米级水凝胶进行表征支持了先前的发现，表明在37°C下，CHP407_P的自旋自旋弛豫时间（即1,259 ms）比CHP407水凝胶（即1,560 ms）要低。形成比CHP407水凝胶更紧密的CHP407_P网络。最后，测定了CHP407_P水凝胶的较低的溶胀能力和抗溶解性。总体，