丙烯酸多元醇水分散体的制备及其稳定性研究

Preparation of an Aqueous Acrylic Polyol Dispersion and Study on Its Stability

制备了一种用于双组分水性聚氨酯涂料的高稳定性的水性丙烯酸多元醇分散体。通过动态光散射仪和热重试验研究了丙烯酸的添加方式、中和度、分散过程中水的添加速率以及分散装置对水性丙烯酸多元醇分散体稳定性的影响。此外采用红外光谱仪(FT-IR)、电化学测试和水溶胀试验分别对丙烯酸树脂的结构耐腐蚀、耐水及涂膜性能进行检测。结果表明丙烯酸两步法加入制备的分散体与丙烯酸一步法加入相比,前者呈现出较好的粒径分布、黏度及热储性能且有较高的酸值,其在水中浸泡24 h后,腐蚀电流增长的程度较小。较高的中和度和降低水的添加速率使分散体的粒径较小,用圆盘分散机分散所得的分散体的性能优于均制分散机制备出的分散体的性能。

An aqueous acrylic polyol dispersion with high stability for two-component waterborne polyurethane coatings is prepared. The method of adding acrylic acid, the neutralization value, the speed of adding water in the process of dispersion and the influence of the dispersing devices on the stability of the aqueous acrylic polyol dispersion are studied through dynamic light scattering apparatuses and thermogravimetric experiments. Besides, FT-IR, electrochemical tests and water swelling experiments are conducted to check the acrylic resin structure＇s anticorrosion, waterproof and film properties. The results show that the dispersion prepared by adding acrylic acid in two stages has better particle size distribution, viscosity and heat accumulation performance and a higher acid value than that prepared by adding acrylic acid in one stage and that the corrosion current increases less after it is submerged in water for 24 h. The higher neutralization value and lower speed of adding water make the dispersion＇s particle size small, and the dispersion prepared with a disc dispersion machine performs better than that prepared with a homogenous dispersion machine.