基于动态硼酸酯键/氢键的自修复水凝胶的制备及性能

Preparation and properties of self-healing hydrogels based ondynamic borate bonds/hydrogen bonds

摘要:

设计了一种新型苯硼酸离子液体（PBA-IL）单体，在TEMPO氧化CNFs的存在下，通过丙烯酰胺（AM）和PBA-IL的一步聚合法，制备了一种具有半互穿网络结构的自修复水凝胶（PAM/PBA-IL/CNF）。通过1H NMR对PBA-IL的化学结构进行分析；通过FT-IR、XPS、SEM对水凝胶的化学结构和物理形貌进行表征；通过拉力试验和自修复实验对其力学性能和自修复性进行测试。结果表明，PBA-IL单体和水凝胶的成功制备，水凝胶具有优异的自修复性能，当PBA-IL的质量分数为30%时，PAM/PBA-IL3/CNF水凝胶的自修复效率为95.43%（150 min内），并且修复后水凝胶的拉伸强度（319.5 kPa）和断裂伸长率（1950.3%）接近于初始的水凝胶。PAM/PBA-IL/CNF水凝胶的自修复性归因于PAM/PBA-IL共聚物与CNFs链上顺式二羟基形成的硼酸酯键及水凝胶内部多重氢键的协同作用。

Abstract:

A novel phenylboronic acid ionic liquid (PBA-IL) monomer was designed, and the self-healing hydrogel (PAM/PBA-IL/CNF) with semi-interpenetrating network was prepared by a one-step polymerization of acrylamide (AM) and PBA-IL in the presence of TEMPO-oxidized CNFs. The chemical structure of PBA-IL was analyzed by 1H NMR. The chemical structure and physical morphology of the hydrogel were characterized by FTIR, XPS and SEM. The mechanical properties and self-healing properties were tested by tensile test and self-healing experiment. The results showed that the PBA-IL monomer and the hydrogel were successfully prepared, and the hydrogel exhibited excellent self-healing properties. When the mass fraction of PBA-IL was 30%, the self-healing efficiency of PAM/PBA-IL3/CNF hydrogel was 95.43% (within 150 min). And the tensile strength (319.5 kPa) and elongation at break (1950.3%) of the self-healed PAM/PBA-IL3/CNF hydrogel approached that of the original hydrogel. The self-healing properties of PAM/PBA-IL/CNF hydrogels were attributed to the synergistic effect of the boronate bonds formed by the PAM/PBA-IL copolymers with the cis-diols on the CNFs chain and the multiple hydrogen bonds inside the hydrogels.