摘要： 选用异佛尔酮二异氰酸酯(IPDI)、己二酸丁二醇酯、2,2-双(羟甲基)丙酸(DMPA)为主要原料,利用氮磷协同阻燃的原理,将N,N-二羟乙基-亚磷酸甲胺二乙酯导入到聚氨酯分子链中制备阻燃型水性聚氨酯乳液。研究发现阻燃剂含量对乳液稳定性、粒径、机械强度、热重性能、极限氧指数等性能均有影响。当阻燃剂含量由0增加到6%时,乳液的稳定性逐渐变差;乳液成膜后,膜的拉伸强度也随之减小,而断裂伸长率则呈现出先增加后减小的现象。与此同时,DSC及TG实验结果表明,随着阻燃剂含量的增加,膜的热分解速率减慢,聚氨酯软、硬段的热分解温度均升高。与没有添加阻燃剂的软、硬段分解温度(200℃与310℃)相比,添加2%、3%、4%、5%的阻燃剂后,其软段分解温度变化不大,而硬段分解温度最大可增加到425℃;氧指数分别由26%增加到33%、34%和33%。这些结果一方面说明N,N-二羟乙基-亚磷酸甲胺二乙酯是非常高效的聚氨酯阻燃剂,另一方面在3%后继续提高阻燃剂含量对氧指数的影响不大。综合上述结果,最优化的阻燃剂配比是阻燃剂含量为2%～3%。

关键词: 水性聚氨酯, 阻燃剂, 亚磷酸二乙酯

Abstract: The aliphatic isocyanate (isophorone diisocyanate, IPDI) and poly (1, 4-butylene adipate)(M_w=1 000)were employed for the preparation of aqueous PU emulsion by using dihydroxymethyl malonic acid(DMPA)as the anionic stabilizer, which was further modified by using (N, N-dihydroxy methyl-amine)diethyl -phosphite (DHMADP) as the flame-retardant component of hard segments. It was observed that the P content affected both the stability of emulsion and the mechanical performance of film made from the emulsion. When the flame retardant content increased from 0 to 6% relative to the total amount of PU, the stability of emulsion was decreased correspondingly the tensile strength of PU film decreased and the elongation at break was increased to 3%, then decreased. Results of DSC/TG tests indicated that with the increase of flame retardant content, the thermal decomposition rate of PU film decreased, and the thermal decomposition temperature of both the soft segments and the hard segments increased. Compared with the decomposition temperatures(200 ℃, 310 ℃)of soft and hard segments without flame retardant, the decomposition temperature of soft segment changed little when adding flame retardant 2%, 3%,4% and 5%,but that of hard segment increased up to 425 ℃, and the LOI of it increased to 33%, 34% and 33%.All these results indicated that the DHARDP was an effective flame retardant and its optimum dosage was between 2%~3%.

Key words: waterbome polyurethanes, flame-retardar, diethyl phosphate