生物质改性阴极聚氨酯电泳漆的制备、结构与性能

摘要

Hydroxyl-terminated cationic waterborne polyurethane resin modified by urushiol was prepared by stepwise polymerization method,after mixed auxiliaries,and then cathodic electrophoretic paint was obtained.The effects of urushiol contents on the structure and properties of the polyurethane (PU)were investigated by Fourier transform infrared spectroscopy(FT-IR),X-Ray Diffraction(XRD) and thermogravimetric analysis(TGA).The results showed that the modification of urushiol on the PU resin improved micro-phase separation of PU,and the order degree of hard segment in hard phase. With an increase of urushiol in content,the performance of the film showed the law of increasing first and then decreasing.When the molar ratio of urushiol to 1,4-butanediol(BDO)reached a proper value of 1:14,the glossiness,hardness,acid resistance and solvent resistance for the film w ere desired.T he glossiness reaches the value of 130,the hardness is about 5H,the acid resistance is around 43 h,and ac-etone wiping times are about 748 times.The modification of urushiol on the PU resin improves the thermal stability of the polyurethane film.%采用逐步聚合的方法在聚氨酯制备中引入漆酚结构,合成出生物质改性的端羟基型阳离子水性聚氨酯,将其与助剂混合制备出阴极电泳漆.采用热失重分析(TG)、傅里叶变换红外光谱、X射线衍射(XRD)等测试方法,研究了漆酚改性聚氨酯树脂的合成、结构与性能.结果表明,漆酚对聚氨酯主链结构的改性促进了聚氨酯树脂的微相分离,增加了硬段区硬段的有序度;随着漆酚用量的增加,聚氨酯漆膜性能如光泽度、耐酸性和耐丙酮擦拭次数均呈现先增大后减少的规律;当漆酚与1,4-丁二醇物质的量比为1:14时,漆膜的光泽度、硬度和耐酸性等性能达到最佳,其光泽度为130,铅笔硬度为5H,耐酸性为43 h,耐丙酮擦拭次数为748次,而且漆酚对聚氨酯树脂的改性改善了漆膜的热稳定性.