具有氢键和二硫键的单宁酸基聚氨酯薄膜制备与性能

以单宁酸作为交联剂、蓖麻油作为聚氨酯的多元醇、异佛尔酮二异氰酸酯作为聚氨酯的多元异氰酸酯、双（2-羟乙基）二硫化物和1, 4-丁二醇作为聚氨酯的扩链剂，采用预聚体法制备单宁酸基聚氨酯，并研究单宁酸和双（2-羟乙基）二硫化物的用量对聚氨酯玻璃化转变温度、热稳定性及自修复性能的影响，同时采用基于脂肪酶的酶降解法评估单宁酸基聚氨酯薄膜的生物降解性能。研究表明，单宁酸用量增加会导致单宁酸基聚氨酯薄膜的玻璃化转变温度上升，并提升热稳定性，而双（2-羟乙基）二硫化物的增加对薄膜的玻璃化转变温度无影响，但薄膜的热稳定性降低；在特定条件下（80 ℃、3 h），STPU4膜自修复率高达95%，此外，经脂肪酶酶解140 h后，STPU4膜的质量损失达68.3%。

Preparation and Properties of Tannic Acid-Based Polyurethane Films with Hydrogen and Disulfide Bonds

Tannic acid was used as the cross-linking agent, castor oil as the polyol of polyurethane, isophorone diisocyanate as the polyisocyanate of polyurethane, and bis(2-hydroxyethyl) disulfide and 1, 4-butanediol as the chain extender of polyurethane. Tannic acid-based polyurethanes were prepared by the pre-polymerization method, and the effects of the dosages of tannic acid and bis(2-hydroxyethyl) disulfide on the glass transition temperatures, thermal stability and self-repairing properties of polyurethanes were studied. self-repairing properties, while the biodegradation properties of tannic acid-based polyurethane films were evaluated using a lipase-based enzymatic degradation method. It was shown that an increase in the dosage of tannic acid led to an increase in the glass transition temperature of tannic acid-based polyurethane films and enhanced the thermal stability, while an increase in bis(2-hydroxyethyl)disulfide had no effect on the glass transition temperature of the films, but the thermal stability of the films was reduced; the self-healing efficiency of the STPU4 films was as high as 95% under the specific conditions (80 ℃, 3 h). In addition, the mass loss of the STPU4 membrane reached 68.3% after 140 h of lipolytic digestion.