单硬脂酸甘油酯改性蓖麻油基水性聚氨酯的制备与性能研究

目的 使用单硬脂酸甘油酯(GMS)对蓖麻油基水性聚氨酯进行改性，增强其防水、耐热和力学性能。方法 使用丙酮法合成不同GMS含量的蓖麻油基水性聚氨酯乳液，进行乳液粒径测定和稳定性试验;使用浇铸法制作薄膜，并进行铅笔硬度测试、力学性能测试、吸水测试、接触角测试、热重测试、DSC、FTIR测试。分析薄膜表面硬度、力学性能、耐水性能、热稳定性、耐热性能和内部结构。结果 当GMS的−OH的摩尔分数为25%时薄膜综合性能最佳，此时膜的抗拉强度为(9.37±1.28)MPa，弹性模量为(250.55±34.05)MPa，薄膜的吸水率降低到12%，薄膜的水接触角为92°。GMS的加入，增加了薄膜的玻璃态转化温度和铅笔硬度，但热稳定性有所下降。结论 GMS的加入增强了蓖麻油基水性聚氨酯的耐水、耐热和力学性能。

Preparation and Properties of Castor Oil Based Waterborne Polyurethane Modified by Glycerin Monostearate

The work aims to improve the waterproofing, heat resistance and mechanical properties of castor oil based waterborne polyurethane through modification by glycerin monostearate (GMS). The emulsion of castor oil based waterborne polyurethane with different GMS contents was synthesized by acetone method and the emulsion particle size measurement and stability test were carried out, and then the film was made by casting and subject to the tests of surface hardness, mechanical properties, water absorption, contact angle, thermogravimetry, DSC and FTIR. The surface hardness, mechanical properties, water resistance, thermal stability, heat resistance and internal structure of the film were analyzed. The film obtained the best comprehensive performance when the mole fraction of hydroxyl group of GMS was 25%. In this case, the film had a tensile strength of (9.37±1.28)MPa and a Young''s modulus of (250.55±34.05)MPa and its water absorption reduced to 12%, and water contact angle was 92°. The addition of GMS increased the Tg and pencil hardness of the film, but decreased the thermal stability. The addition of GMS enhances the waterproofing, heat resistance and mechanical properties of castor oil based waterborne polyurethane.