不同硬段型水性聚氨酯胶黏剂的合成和性能比较

 用异佛尔酮二异氰酸酯（IPDI）/甲苯二异氰酸酯（TDI）、聚醚二元醇（N210）、二羟甲基丙酸（DMPA）为原料，采用两步法合成了不同硬段型聚氨酯预聚体，并用含三乙胺的去离子水中和乳化，乙二胺扩链，得TDI型和IPDI型水性聚氨酯（WPU）胶黏剂。通过红外、黏度、热重等分析方法，对不同硬段型WPU乳液、胶膜进行了结构和性能考查，对异氰酸酯基（NCO）含量进行定量、定性分析。结果表明，随着反应的进行NCO含量逐渐减少，至200min时基本达到理论值。当DMPA含量分别为3.0%（W/W）和8.0%（W/W）时，得到的TDI型和IPDI型WPU稳定、透明、耐溶剂性相对较好；此条件下的黏度分别为2000和6950mPa·s；两者的热稳定性都较好，起始分解温度分别达到350.8和295.0℃；IPDI型WPU机械强度高，拉伸强度为3.37MPa。综合比较各种性能，IPDI型WPU胶黏剂相对较佳。

Synthesis and Performance of Waterborne Polyurethanes with Different Hard Segments

Different hard segment waterborne polyurethane prepolymers are synthesized in two steps from isophorone diisocyanate (IPDI)/toluene diisocyanate (TDI), polyester polyol (N210), dimethlolpropionic acid (DMPA), using deionized water with triethylamine to neutralize and emulsify, then being chained with ethylene diamine (EDA), to obtain WPU adhesives from TDI and IPDI. The structure and properties of different hard segment WPU emulsions and films are investigated by FTIR, Viscosity, Thermo Gravimetric(TG) methods. The NCO contents are analyzed by the quantitative and qualitative analysis methods. It is shown that with the reaction in process, the NCO group content is gradually reduced, and it takes at least 200min to reach the theoretical value. WPU adhesives from TDI and IPDI emulsions are more stable, transparent, and the solvent resistance is better when the contents of DMPA are 3.0%(W/W) and 8.0%(W/W), respectively; Under these conditions, the viscosity can reach 2000mPa·s and 6950mPa·s, respectively. Both WPU films from TDI and IPDI have good thermal stability, and the thermal decomposition temperatures are 350.8℃ and 295.0℃, respectively. WPU from IPDI has higher mechanical strength, with tensile strength of 3.37MPa. The overall performance of WPU adhesive prepared by IPDI is better than that by TDI.