N,N-双(2-羟乙基)-2-氨基乙磺酸钠为扩链剂的磺酸型聚氨酯水凝胶制备及性能

以异佛尔酮二异氰酸酯(IPDI)、聚乙二醇-2000(PEG)为主要原料,二羟甲基丙酸(DMPA)和N,N-双(2-羟乙基)-2-氨基乙磺酸钠(BES-Na)为亲水性扩链剂,制备了一系列磺酸型聚氨酯水凝胶(WPUHs)。通过X射线衍射仪、热重分析仪和电子万能测试机对凝胶的结构和性能进行了表征。结果表明,随着BES-Na质量分数的增加,WPUHs的热稳定性逐渐增加,WPUH7(BES-Na质量分数为3.46%)的压缩强度和压缩模量比WPUH1(BES-Na质量分数为0%)分别提高了2.9倍和3.6倍。BES-Na的质量分数对WPUHs的溶胀初期过程影响显著,WPUHs的平衡溶胀比从20.6增加至29.3。WPUHs具有良好的温度和pH敏感性,在10~45℃范围内,WPUH7平衡溶胀比从17.6增大至33.8,在pH值为2~10范围内,WPUH7平衡溶胀比从21.7增大至70.6。

Preparation and Properties of Sulfonic Waterborne Polyurethane Hydrogels with Sodium N,N-Bis (2-hydroxyethyl)-2-aminoethane Sulfonate as Chain Extender

A series of sulfonic waterborne polyurethane hydrogels(WPUHs) was prepared by in-situ polymerization using 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate(IPDI), polyethylene glycol(PEG) and diethylene glycol(DEG) as raw materials, and 2,2-dimethylol propionic acid(DMPA) and N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid sodium salt(BES-Na) as hydrophilic chain extenders. The structure and properties of the gels are characterized by X-ray diffractometer, thermogravimetric analyzer and electro-mechanical universal testing machine. The results show that the thermal stability of the hydrogels increases gradually with the increase of BES-Na mass fraction, and the compressive strength and compressive modulus of WPUH7 hydrogel containing 3.46% mass fraction BES-Na are 2.9 times and 3.6 times higher than those of the WPUH1 hydrogel containing 0% mass fraction BES-Na, respectively. The swelling ratio increases from 20.55 to 29.25, and the increase of BES-Na mass fraction has a significant influence on the initial process of hydrogel swelling. At the same time, the swelling ratio of WPUH7 hydrogel increases from 17.64 to 33.80 in the range of 10~45 ℃ and from 20.74 to 70.69 in the range of pH 2~10, indicating that hydrogels have good sensitivity to temperature and pH.