Preparation and Characterization of Two-component Waterborne Polyurethane Comprised of Water-soluble Acrylic Resin and HDI Biuret

A two-component waterborne polyurethane(2K-WPU) was prepared by mixing water-soluble acrylic resin and hexamethylene diisocyanate biuret, and then diluted for phase inversion with water. Compared with water-soluble acrylic resin, the phase inversion of 2K-WPU occurs at lower water content. It is indicated by TEM that 2K-WPU parti-cles show a core-shell structure, in which HDI biuret is encapsulated by hydrophilic acrylic resin. 2K-WPU emulsion with HDI biuret has larger particle size and narrower distribution index, while for 2K-WPU emulsion with HDI iso-cyanurate, the latex not only has large particle size, but also has two-peak distribution. FTIR shows that the reaction be-tween HDI biuret and acrylic resin can complete in 12h. In addition, studies on effect of composition of acrylic resin on performance of 2K-WPU show that narrowing the polar difference between water-soluble acrylic resin and HDI biuret and improving the miscibility of two components are the key to prepare the transparent and high gloss films with high crosslinking density.

水性双组分丙烯酸-聚氨酯的合成与表征(英文)

使用相转化法,即将水溶性丙烯酸树脂和HDI缩二脲混合,然后加水稀释转相,制备了水性双组分丙烯酸聚氨酯。研究了丙烯酸树脂配方对双组分聚氨酯性能的影响,并用红外光谱(FTIR)对涂膜固化进行了表征。结果表明,以丙二醇甲醚醋酸酯为溶剂,在羟值为120 mgKOH·g-1、酸值为30 mgKOH·g-1的水溶性丙烯酸树脂中,添加10 %的甲基丙烯酸异冰片酯,获得的双组分聚氨酯乳液粒径小。室温干燥12 h,固化反应完成,涂膜交联密度高。

水性聚氨酯丙烯酸酯的多重交联改性及其相转变

以异佛尔酮二异氰酸酯(IPDI)、聚醚二元醇(N220)、甲基丙烯酸甲酯(MMA)为主要原料合成了脂肪族聚氨酯-丙烯酸酯复合乳液,并采用蓖麻油、环氧树脂和三羟甲基丙烷对其进行改性。通过综合性能测试研究了各种交联剂添加量对乳液及其涂膜性能的影响。并通过粘度和电导率测试研究了聚氨酯剪切乳化过程的相转变及各交联剂对相转变的影响。结果表明:当蓖麻油、环氧树脂和TMP的添加量分别为7%、3%、3%时,可得到稳定、耐水耐介质性好、硬度较高、力学性能突出的聚氨酯丙烯酸酯复合乳液;各交联剂都会使相变点后移,尤其以环氧树脂的影响最为明显。