紫外光固化聚氨酯丙烯酸酯粘结剂的优化设计

Optimum Design of Ultraviolet Curing Adhesive Based on Polyurethane Acrylate

采用红外光谱对聚氨酯丙烯酸酯(PUA)涂料的紫外固化过程进行定量分析;测试了不同配方和固化条件下涂膜的摆杆硬度、柔韧性和抗冲击性;考察了γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)对粘结剂附着力的影响,并对其作用机制进行了分析。结果表明,固化过程中C=C双键发生聚合,其转化率反映了涂膜的固化程度;增大光强、减少稀释剂用量和延长固化时间均有利于提高双键转化率和摆杆硬度;随着光引发剂浓度的增加,双键转化率先增后减;增大二官能PUA比例能够提高涂膜柔韧性和抗冲击性;KH570能够改善涂膜附着力,加入量越大改善效果越明显,且静置对附着力有很大影响;其作用机制是KH570分子中的双键与丙烯酸双键发生聚合,羟基与基底间形成氢键作用。

The ultraviolet curing process of polyurethane acrylate（ PUA） coating was monitored by infrared spectroscopy. The properties such as pendulum hardness,flexibility and impact resistance of the coating were measured under various formulations and curing conditions. The effects of γ-methacryloxypropyltrimethoxysilane（ KH570） on adhesion of adhesive were studied followed by enhanced mechanism. The results show that,increasing light intensity,reducing the amount of diluent and prolonging curing time are all beneficial to increase C = C conversion and the pendulum hardness. With increase of the photoinitiator concentration,C = C conversion increases firstly and then decreases. The flexibility and impact resistance of the coating are better with the higher proportion of polyurethane diacrylate. In addition,KH570 could enhance the coating adhesion,especially standing a period of time. It is concluded that the main mechanism is the polymerization of C = C between KH570 and PUA and the formation of hydrogen bond between the hydroxyl group of hydrolyzed KH570 and the substrate.