海藻酸钠交联水性聚氨酯皮革涂饰剂的合成及应用

Synthesis and application of sodium alginate cross-linked waterborne polyurethane leather finishing agent

以聚己内酯二元醇(PCL-1000)、六亚甲基二异氰酸酯(HDI)为主要原料,2,2-二羟甲基丙酸(DMPA)为亲水扩链剂,海藻酸钠(SA)为交联剂,成功合成了海藻酸钠交联水性聚氨酯(SAWPU)。在成膜过程中利用SA分子结构上的-COOH与金属Ca2+发生螯合反应,制备出高交联度的聚氨酯胶膜。通过傅立叶变换红外光谱仪(FT-IR)、激光粒度分析仪(DLS)、热重分析仪(TGA)等对SAWPU进行结构表征及性能测试,并用SAWPU乳液制备出水性皮革涂饰剂将其涂饰在皮革表面,对皮革的透水汽性和柔软度进行测试。试验结果表明:乳液粒径分布较小,储存稳定性良好,胶膜吸水率降低至7.2%,热稳定性提高,同时当SA添加量为0.3%时,拉伸强度达76.55 MPa,断裂伸长率为1 253.95%,综合性能良好。

Using the polycaprolactone diol(PCL-1000),hexamethylene diisocyanate(HDI) as the main raw material,2,2-dimethylolpropionic acid(DMPA) as hydrophilic chain extender,sodium alginate(SA) as a cross-linking agent,the sodium alginate cross-linked waterborne polyurethane(SAWPU) was successfully synthesized. In the film formation process,a high degree of cross-linking polyurethane film was prepared by chelation reaction of -COOH on the molecular structure of SA with metal Ca2+ ions. Structural characterization and performance testing of SAWPU were studied by Fourier transform infrared spectroscopy(FT-IR),laser particle size analyzer(DLS),thermogravimetric analyzer(TGA),etc.The SAWPU emulsion was used to prepare water-based leather coating reagents,which were then coated on the leather surface.The water vapor permeability and softness of SAWPU coated leather were tested.The experimental results show that the emulsion particle size distribution is small,the storage stability is good,the water absorption rate of the film is reduced to 7.2%,the heat stability is improved.When the SA addition amount is 0.2%,the tensile strength is 56.57 MPa,and the elongation at break is 1 160.06%,the comprehensive performance is good.