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以聚四氢呋喃二醇、聚己二酸丁二醇酯、端羟基硅烷和异佛尔酮二异氰酸酯等为主要原料,以2,2-二羟甲基丙酸和磺酸型扩链剂为亲水扩链剂,采用自乳化和外乳化相结合的方法合成阴离子型高固含量水性聚氨酯乳液。考察了预聚时间、有机硅加量、乳化剂和扩链剂含量、R值(NCO/OH)等对乳液和成膜性能的影响。通过红外光谱、热重分析对改性前后水性聚氨酯结构进行表征。结果表明:预聚时间为2.0～2.5h,磺酸型扩链剂含量为0.27%,外乳化剂用量为1.6%,R=1.3,有机硅含量为2.5%时,能得到固含量53%、黏度低,稳定性、耐水性、耐热性优异的水性聚氨酯乳液。
Polytetrahydrofuran diol, polybutylene adipate, hydroxy-terminated silane and isophorone diisocyanate as the main raw materials, 2,2-dimethylolpropionic acid and sulfonic chain extender as a pro Water chain extender, the use of a combination of self-emulsifying and emulsifying the synthesis of anionic high solids aqueous polyurethane emulsion. The effects of prepolymerization time, amount of silicone, content of emulsifier and chain extender, R value (NCO / OH) on the emulsion and film forming properties were investigated. The structure of waterborne polyurethane was characterized by IR and TGA. The results showed that the prepolymerization time was 2.0 ~ 2.5h, the content of sulfonic acid chain extender was 0.27%, the amount of external emulsifier was 1.6%, R = 1.3, the content of solid was 53% when the content of organic silicon was 2.5% Low viscosity, stability, water resistance, heat resistance of the water-based polyurethane emulsion.