HDI三聚体改性磺酸盐型高固含量水性聚氨酯的制备与性能研究

摘要

Sulphonated waterborne polyurethane emulsions with 50% solid-content were successfully synthesized by using poly(1,4-butanediol adipate)diol (PBA), isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI) as the main raw materials, N-(2-aminoethyl)-amino ethane sulphonated sodium as hydrophilic chain extender, and HDI trimer (HT) as a modifier. The effects of the feeding method and the amount of HDI trimer on the latex particle size and distribution, Zeta potential and viscosity of waterborne polyurethane emulsions, and the water resistance, crystallinity and mechanical properties of the cast films of synthesized polyurethane were studied respectively by Malvern laser particle size analyzer, Brookfield viscometer, universal tensile machine, Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H-NMR), X-ray diffraction analysis (XRD), differential scanning calorimetry analysis (DSC) and transmission electron microscopy (TEM). The results show that, with the increase of the amount of HDI trimer, the viscosity of waterborne polyurethane emulsion decreases, the average particle size and its distribution of latex particles increase, and the tensile strength and elongation at break of the cast films are increased firstly and then decreased. The introduction of the HDI trimer into the polyurethane chain destroys the arrangement regularity of the polyurethane soft segment, which results in a slightly lower film crystallinity. When the ratio of HDI trimer to IPDI is 1:3 (mass ratio), the synthesized polyurethane shows excellent performance, which has the emulsion particle size of 199.3 nm, Zeta potential of-42.7 mV, the film water absorption of 3.8%and the film relative crystallinity of 50.62%.%　　以异氟尔酮二异氰酸酯(IPDI)、六亚甲基二异氰酸酯(HDI)、聚己二酸1，4-丁二醇酯二醇(PBA)为主要原料，以乙二胺基乙磺酸钠(AAS)为亲水性扩链剂，以HDI三聚体(HT)为改性剂，制得了固含量为50%的磺酸盐型水性聚氨酯乳液。采用马尔文激光粒度分析仪、Brookfield黏度计、万能拉力机、傅里叶变换红外光谱(FT-IR)、核磁共振(1H-NMR)、X-射线衍射分析(XRD)、差示扫描量热分析(DSC)和透射电镜(TEM)等分析测试技术，研究了HDI三聚体加料方式和用量对水性聚氨酯乳胶粒子大小及其分布、Zeta电位、乳液黏度和胶膜的耐水性、结晶性及力学性能等的影响。研究结果表明，随着改性剂HDI三聚体用量的增大，水性聚氨酯乳液黏度减小，乳胶平均粒径增大且分布变宽，胶膜的拉伸强度和断裂伸长率先增大后减小；HDI三聚体的加入，破坏了聚氨酯软段排列的规整性，使得胶膜的结晶度稍有降低。当HDI三聚体用量与IPDI用量比为1：3时(质量比)，所得聚氨酯乳液的粒径为199.3 nm，Zeta电位为-42.7 mV，胶膜吸水率为3.8%，相对结晶度为50.62%，具有优良的综合性能。