材料期刊网

以异佛尔酮二异氰酸酯(IPDI)和聚醚二元醇(N210、N220、N330)为基本原料,1,4-丁二醇(BDO)和2,2-二羟甲基丙酸(DMPA)为扩链剂,蓖麻油(C.O.)和三羟甲基丙烷(TMP)为交联剂,三乙胺(TEA)为中和剂合成了脂环族水性聚氨酯预聚物.通过测定预聚物加水乳化过程中的黏度和电导率,研究了其相转变行为.结果表明:聚醚二元醇相对分子质量、n(-NCO):n(-OH)值、羧基含量、中和度和交联剂用量对相转变有影响.聚醚二元醇相对分子质量越大,羧基含量、中和度和交联剂用量的增加,相变点延后,n(-NCO):n(-OH)越小,相变点越滞后.通过测定PU-H_2O体系相图得知,只有离子含量在0.238 mmol/g以上时才能得到贮存稳定性好的乳液.

Alicyclic aqueous polyurethane prepolymer was synthesized with isophorone diisocyanate (IP-DI) and polyether diol (N210, N220, N330) as raw materials, 1,4-butanediol (BDO) and 2,2- dime-thylol propionic acid (DMPA) as chain extenders, castor oil (C.O.) and trimethylolpropane as crosslinking agent, triethylamine(TEA) as neutralization agent. Its phase inversion behavior was studied by determina-tion of viscosity and conductivity during emulsification. The experimental results showed that several factors can affect the phase inversion heavily, including the molecular weight of polyether diol, the NCO/OH ratio, carboxyl and crosslinking agent content and neutralization degree. With the increasing of the molecular weight of polyether diol, carboxyl and crosslinking agent content and neutralization degree, and with the de-creasing of NCO/OH ratio, the phase inversion delays. By studying of the phase diagram of PU-H_2O sys-tem, it is known that the emulsion is not stable until the content of ion reaches above 0.238 mmol/g.