木质素改性水性聚氨酯胶膜的制备与性能

Preparation and Properties of Lignin Modified Waterborne Polyurethane Film

以异佛尔酮二异氰酸酯(IPDI)和聚四氢呋喃醚二醇(PTMG)为主要原料,碱木质素(LG)为改性剂,二羟甲基丙酸(DMPA)为亲水扩链剂,合成了一系列木质素改性水性聚氨酯(LWPU)。研究了LG用量、n(NCO)/n(OH)及DMPA用量对LWPU胶膜力学性能和耐水性能的影响。结果表明,当LG质量分数为0.75%,n(NCO)/n(OH)为5∶1,DMPA质量分数为6%时,胶膜的综合性能较好,其吸水率仅为3.24%,耐水性能明显提高。通过红外光谱、热重分析、X射线衍射及原子力显微镜和扫描电镜对LWPU胶膜的结构与性能等进行了表征,热重分析结果表明,LG的加入可提高聚氨酯材料的热稳定性。加入适量的木质素可以改善水性聚氨酯的耐水性及热稳定性。

A series of lignin modified waterborne polyurethanes（ LWPU） were prepared by prepolymer method with isophorone diisocyanate（ IPDI） and polytetramethylene ether glycol（ PTMG） as raw materials,alkali lignin（ LG） as modifier and dimethylol propionic acid（ DMPA） as hydrophilic chain extender. The effects of the dosage of LG,n（- NCO） ∶ n（- OH） and the dosage of DMPA on properties of LWPU films were systematically studied. The results show that when the LG dosage is 0. 75%,n（ NCO） / n（ OH） is 5∶ 1 and DMPA dosage is 6%,the comprehensive performance of LWPU is better,the water absorption only is 3. 24%,the water resistance is obviously improved. The FT-IR,TG,XRD,AFM and SEM were used to characterize the structure and properties of LWPU. TGA analysis indicates that the thermal stability of LWPU is improved by using LG as modifier. Adding a balanced amount of lignin can significantly improve the water resistance and thermal stability of polyurethane films.