室温自交联水性丙烯酸树脂分散体的制备与性能研究

Preparation and Properties of Room Temperature Self-Crosslinking Waterborne Acrylic Resin Dispersion

水性丙烯酸树脂在耐光性、耐候性、色泽等方面显示了优良的性能,但是在成膜干燥速度、耐水性和储运稳定性等方面还存在明显不足。针对上述问题,本研究以酮肼交联改性为基础,采用自由基共聚的方法,制备出了室温自交联水性丙烯酸分散体。傅里叶转换红外光谱(FT-IR)分析证实了双丙酮丙烯酰胺(DAAM)和己二酸二酰肼(ADH)在室温下发生了酮肼交联反应,并对交联机理进行了研究;差式扫描量热(DSC)分析表明,加入DAAM/ADH交联体系的树脂涂膜具有更高的玻璃化转变温度(Tg)和热稳定性;在研究范围内,随着交联剂用量的增加,合成树脂的吸水率先降低后升高,交联度、硬度、断裂强度逐渐提高,伸长率降低。

Waterborne acrylic resins have been widely used in the field of coatings for its excellent properties in terms of UV resistance,weatherability and color,etc.However,there still exists some obviously problems,such as the low drying speed of wet film,the low water resistance and storage stability,etc.In this article,the room-temperature self-crosslinking waterborne acrylic resin dispersions are prepared by the free-radical copolymerization method on the basis of ketonehydrazine crosslinking.FT-IR analysis shows that the ketone-hydrazine crosslinking reaction occurrs between DAAM and ADH at room temperature.Besides,the mechanism of ketone -hydrazine crosslinking reaction is studied.The differential scanning calorimetry (DSC) indicates that the resin coating with DAAM/ADH has higher glass transition temperature (Tg) and thermal stability.In addition,with the increase of the amount of crosslinking agent,the water absorption of the synthetic resin decreases firstly and then increases.Meanwhile,the crosslinking density,the hardness and the breaking strength gradually increase while the elongation decreases.