有机硅改性水性聚碳酸酯型聚氨酯的合成与性能研究

Preparation and Properties of Organic-silicone Modified Water-borne Polycarbonate Polyurethane Used as Leather Finishing Agent

研究了以4,4'-二苯基甲烷二异氰酸酯和异氟尔酮二异氰酸酯、聚碳酸酯二元醇和羟甲基酸类扩链剂为原料,合成了阴离子聚碳酸酯型水性聚氨酯,在此基础上用有机硅对其进行改性,探究有机硅改性对于水性聚氨酯性能的改善。结果表明:水性聚氨酯较适宜的合成工艺条件为初始n(—NCO):n(—OH)(R)=3.5,三羟甲基丙烷的质量分数为3%,2,2-二羟甲基丁酸占总质量的6%,羟基硅油的质量分数为1%,预聚反应时间在3.5h左右,预聚温度控制在75℃,扩链温度降低到55℃为宜;有机硅改性后聚氨酯材料的拉伸强度增大,断裂伸长率下降,成膜塑感加强;有机硅的加入在很大程度上提高了聚氨酯膜的耐水性。

The anionic water- borne polycarbonate polyurethane was synthesized by polycarbonate diols, diphenylmethane diisocyanate（ MDI）, isophorone diisocyanate（ IPDI）, and hydroxyl methyl acids as chain extender agent. The influences of organic silicon on the properties of the PU film were also explored. The results show that the optimum conditions for synthetizing water - borne polyurethane are as follows ： n（-NCO） /n（-OH） is 3.5, the mass fraction of TMP is 3%, the total dosage of DMPA is 6% , the mass ratio of organic silicone is 1% , and the prepolymer is obstained for 3.5h around 75℃, the temperature of extender chain is 55 ℃. By testing variety of properties, the mechanical property is enhanced after modified, the tensile strength is increased and elongation at break is down. Also organic silicon improves the water resistance of WPU membranes.