用于双组分水性聚氨酯涂料的新型羟基丙烯酸酯分散体

以偶氮二异丁腈(AIBN)为引发剂,丙酮为溶剂,通过多段溶剂聚合—相转移乳化法合成水性聚丙烯酸酯复合分散体(PADC)。该聚合物包括亲水性含羧酸盐的聚丙烯酸酯(PA)与疏水性不含羧基盐PA。比较了新型的PADC,传统方法合成的聚丙烯酸酯分散体(PAD)与聚丙烯酸乳液(PAE)的性能。结果表明:通过调节亲水聚合物含量和亲水聚合物上羧酸盐的浓度可以控制分散体的粒径与分布。与传统的聚合物水分散体和聚合物乳液相比,该聚合物水分散体不仅具有高固体含量和低挥发性有机化合物(VOC)含量、较低亲水羧酸盐浓度等优点;且对多异氰酸酯固化剂具有较好的乳化能力,采用该类分散体与多异氰酸酯固化剂配制的双组分水性聚氨酯涂膜具有高光泽(60°光泽为90%)、高硬度(摆杆硬度0.80)、优异的耐水性和耐溶剂性能,良好的热稳定性。同时通过红外谱图(FT-IR)对PADC与多异氰酸酯固化剂的结构与交联进行了表征。

Present problems in the use of water-borne wood coatings and the countermeasures

With azobisisobutyronitrile （AIBN） as initiator, acetone as solvent and through multistage solvent polymerization and phase transfer emulsifying method, the water-borne acrylate polymer dispersion is prepared. The polymer contains hydrophilic carboxylate-bearing PA and hydrophobic non-carboxylate PA. This paper compares the performances of new PAD dispersion, traditional-method PAD and acrylic emulsion. The results show that the particle size of the dispersion can be controlled through controlling the content of hydrophilic polymer and controlling the concentration of carboxylate in hydrophilic polymer. Compared with traditional polymer dispersion and polymer emulsion, this polymer dispersion is not only of high sodid content, low VOC content and low concentration of carboxylate, but also is of good emulsifying ability to PU curing agent. The waterborne two-package PU film from the dispersion is of high gloss （90% when 60°）, high hardness （pendulum rod）, perfect water resistance, solvent resistance, and excellent heat stability.