新型阳离子型水性聚氨酯-脲乳液的合成研究

由聚酯多元醇(JW 2503)与甲苯二异氰酸酯(TD I)预聚后,经二乙烯三胺(DETA)扩链、环氧氯丙烷封端、冰乙酸中和制得了新型阳离子型水性聚氨酯-脲(WPUU)乳液。用FT-IR等方法对制备的WPUU乳液结构及有关性能进行了分析和表征。讨论了初聚n(NCO)/n(OH)、DETA的加料方式、DETA质量分数及中和度等因素对WPUU乳液及其涂膜性能的影响。研究结果表明,当初聚n(NCO)/n(OH)=2.4~2.6、DETA=6%~7%及中和度为90%~100%,且采用饥饿加料方式时,制得的WPUU乳液的贮存稳定性在12个月以上。WPUU涂膜具有较好的耐水性和耐化学品性能,WPUU涂膜的硬度(邵氏A)46,拉伸强度7.8 MPa,断裂伸长率760%,脆性温度-30℃。

Synthesis of cationic waterborne polyurethane-urea emulsion

The novel cationic waterborne polyurethane-ureas(WPUU) emulsion were synthesized by prepolymerization of polyester glycol and toluene diisocyanate,and by chain-extending with diethylenetriamine and by end-capping with epichlorohydrin and then neutralized with anhydrous acetic acid.The structure and properties of WPUU were studied with FT-IR,etc.The effects of the mole ratio of n(NCO)/n(OH) in primary polymerization,the addition method of DETA,the mass fraction of DETA and neutralization degree on the properties of the WPUU emulsion and its film were discussed.It was found that the WPUU emulsion had better pot life(more than 12 months) when the mole ratio of n(NCO)/n(OH) in primary polymerization was 2.4~2.6,the mass fraction of DETA was 6%~7%,the neutralization degree was 90%~100% and combined with starved addition method.The film of the WPUU emulsion has good water resistance and chemical resistance properties,the hardness(shore A) of its film could reach 46,tensile strength 7.8 MPa,elongation at break 760%,fragility temperature-30 ℃.