Ultraviolet,water, and thermal aging studies of a waterborne polyurethane elastomer-based high reflectivity coating

A waterborne aliphatic polyurethane-based coating was studied for accelerated ultra-violet (UV), water (WT), and thermal (TH) aging for a period of 1000 h. To monitor the coating durability, samples were tested every 200 h. ATR-FTIR spectroscopy was used to monitor the chemical changes occurring during the aging process. UV–vis with integrating sphere was used to track the change in diffused reflectance, while the optical microscope and the scanning white light interferometry (SWLI) were used for surface characterization. FTIR studies of coatings subjected to UV exposure indicated a decrease in functional groups such as CONH, CH, CO, and COC. The appearance of functional groups such as NH is attributed to chain scission of the polyurethane binder in the coating. Investigation of the degradation mechanism in water and thermal aging showed physical effects through water penetration and the mismatch in the coefficient of thermal expansion as the primary causes of degradation. In all aging scenarios, the reduction of reflectivity was largely due to physical defects caused by the different aging mechanisms.     

水性紫外光固化涂料的研究进展

介绍了水性紫外光固化涂料(UVCC)的几种制备方法,阐述了水性UVCC在建筑涂料、包装材料、汽车行业等各领域的应用,并对水性UVCC近年来的发展趋势做了总结,认为未来水性紫外光固化技术将朝着制备新型的齐聚物、开发新型的活性稀释剂、研究新型固化体系发展.     

光固化环氧丙烯酸酯体系的增韧研究

在癸二酸增韧环氧丙烯酸酯(GEA)的基础上,研究了通过加入聚氨酯丙烯酸酯(PUA),改善环氧丙烯酸酯紫外光固化材料的柔韧性,同时避免强度的较大损失。结果显示,对于癸二酸改性的环氧丙烯酸酯(癸二酸与环氧树脂的摩尔比为0.3),当GEA∶PUA∶稀释剂:光引发剂(质量比)为61.6∶15.4∶20∶3时,PUA共混改性的GEA光固化体系具有良好的综合性能,此时拉伸强度为8.84 MPa,断裂伸长率为109%,柔韧性为1 mm。     

丙烯酸接枝淀粉基可降解紫外光固化高吸水性树脂的制备与性能

以丙烯酸接枝淀粉为基体,不饱和聚酯酰胺脲树脂为交联剂制备出一种可降解高吸水性树脂,该树脂不加任何光引发剂即可紫外光固化成膜。研究了树脂的吸水速率及交联剂的加入量、光固化时间对产品吸水率的影响。结果表明,该高吸水性树脂对不同溶液均具有较好的吸收能力,吸水速度较快,在蒸馏水、自来水、0.9%NaCl溶液、0.9%KCl溶液中的吸水率分别为905,3501,00,120 g/g;10 min内对蒸馏水的吸收倍率达200 g。该高吸水性树脂的降解从表面开始,逐渐向里面降解。     

水性紫外光固化纳米透明隔热涂料的研制

合成了聚氨酯丙烯酸酯预聚物,添加预制的功能纳米粉体水性浆料,制备了水性紫外光(UV)固化纳米透明隔热涂料。研究表明,水性浆料的平均粒径为27.8nm,添加到预聚物中后涂料的平均粒径为38.8nm;从涂层的综合性能、成本等因素考虑,以隔热粉体的用量为4.2%、涂层厚度为8μm为宜,涂层玻璃的可见光透过率达80%,涂层玻璃比空白玻璃在平衡时的温度降低10℃以上,并具有很好的硬度、耐磨、耐水等基本性能。     

Preparation of nanocoatings in the presence of precipitated CaCO3 fillers by UV-curing

Various methods were employed to prepare precipitated calcium carbonate (PCC) particles. Particle size and morphology were dependent on reaction conditions as well as temperature, reagents and stirring, either mechanical or by ultrasound probe sonication. Sonication helped to reduce the size of CaCO₃ particles as well as the precipitation time. Sonication was also used to disperse PCC particles in the UV-curable formulations as well as for preparation of the PCC. Formulations containing precipitated calcium carbonates and ground calcium carbonates in various grades were cured by a Mini UV-Cure device. Mechanical and thermal properties of films were characterized with a Dynamic Mechanical Analyzer (DMA). SEM analysis was also used to determine the shape and the size of the PCCs. Sonication decreased the precipitation time of calcium carbonate at least four times more than that of conventional precipitation procedures and the dispersion of particles in the formulations increased to a great extent.     

光敏预聚物四氢邻苯二甲酸二缩水甘油丙烯酸酯合成工艺的优化

以四氢邻苯二甲酸二缩水甘油酯与丙烯酸反应制备缩水甘油丙烯酸酯,优化了合成反应的条件,并用红外光谱对产物结构进行了表征.研究结果表明其适宜的反应条件为:用四乙基溴化铵作为催化剂,用量1.1%;反应温度90～100℃;用对羟基苯甲醚作为阻聚剂,用量0.08%;投料的羧基当量与环氧基当量比为1.02:1.该预聚物可与活性稀释剂、光引发剂制成光亮透明、高硬度的紫外光固化涂料,并通过TGA对其固化膜的热性能进行了研究,结果表明固化膜具有较高的耐热性.     

紫外光固化引发剂JD102的合成新工艺

紫外光固化引发剂是光固化技术的核心组成,用量少,但对反应的性能起着关键作用。光固化引发剂JD102(化学名称:1-[4-(2-羟乙氧基)苯基]2-羟基-2-甲基-1-丙酮)具有低气味、耐黄变形好、透明性佳、抗氧化阻聚、可水溶、符合FDA认证的优点,广泛用于UV油墨、木器涂料、光学等高端领域。本文以乙二醇苯醚醋酸酯和异丁酰氯为原料,通过对传统合成工艺的改进,使反应简捷,同时采用相转移催化技术,使反应效率更高、环保性更好地合成出紫外光固化引发剂JD102,并成功进行了产业化。     

光固化不饱和聚酯树脂研究进展

综述了光固化不饱和聚酯树脂体系研究进展,其中包括:不饱和聚酯光敏预聚物的合成,可见光固化树脂,光固化UPR复合材料,光固化粉末涂料,紫外光固化胶衣树脂,光固化胶粘剂等。     

环氧丙烯酸酯涂料的紫外固化研究

采用E-44环氧树脂与丙烯酸反应，用翁盐作催化剂，制备了适于配制竹木基涂饰的紫外光固化的环氧丙烯酸酯预聚物，讨论了催化剂的种类对合成反应的影响。对固化产物进行了红外表征。光引发剂种类和交联剂含量对固化速率的影响、光引发剂含量对凝胶含量的影响、灯距对固化时间的影响、固化时间对涂膜性能的影响也进行了讨论。