PUA复合分散体稳定性的影响因素

Factors Influencing Stability of PUA Hybrid Dispersion

用丙酮法合成了经三羟甲基丙烷（TMP）、环氧树脂（E-20）和甲基丙烯酸甲酯（MMA）改性的阴离子型自乳化水性聚氨酯（Pu）分散体，得到了具有核壳结构的聚氨酯-聚丙烯酸酯（PUA）复合分散体。研究了n（NCO）／n（OH）、二羟甲基丙酸（DMPA）、TMP、E-20、MMA和乙二胺（EDA）用量对复合分散体粒径、贮存稳定性、稀释稳定性、离心稳定性、Ca^2＋离子稳定性、冻融稳定性的影响。结果表明：当n（NCO）／n（OH）=1．3～1．5、n（NH：）／n（NCO）=0．3～0．5，以及DMPA、TMP、E-20和MMA在PUA中的质量分数分别为7．5％、1．5％-3．0％、4％-6％和20％～30％时，获得了漆膜摆杆硬度大于0．75、吸水率低于8．9％、贮存稳定性按GB6753．3-86检测，30d未出现不良变化的PUA复合分散体。目前，该分散体作为水性木器漆的树脂，已经在国内某企业稳定生产和销售，累计销售量已达8000t。

An anionic self-emulsified waterborne polyurethane dispersion, which was modified by trimethylolpropane （ TMP）, epoxy resin （ E - 20） and methyl methacrylate （ MMA）, was prepared using acetone as the solvent. Then, a core/shell waterborne polyurethane/polyacrylate （PUA） hybrid dispersion was obtained. When n（NCO） ：n （OH） = 1.3 - 1.5, n （NCO） ： n （ NH2 ） = （0. 3 - 0. 5 ） ： l, charges of DMPA,TMP, E - 20 and MMA were 7.5%, 1.5% - 3.0% ,4% - 6% and 20% - 30% （ mass fraction to PUA）, respectively, a PUA hybrid dispersion with hardness 〉 0. 75, water uptake 〈 8.9% and good storage stability （unchanged after 30 days according to GB6753.3-86 ） was obtained. At present, this kind of dispersion is produced and sold regularly as resin for waterborne wood coating in a domestic manufactory, and about 8 000 tons of this kind of dispersion have been sold.