表面接枝含氟树脂改性HGB对聚氨酯涂层耐老化性能的影响

目的在中空玻璃微珠(HGB)表面接枝含氟树脂,以其为填料改善聚氨酯(PU)涂层的耐老化性能。方法采用表面接枝法将中空玻璃微珠分别经NaOH溶液、硅烷偶联剂KH550、HDI三聚体、含氟树脂处理,制备表面接枝含氟树脂的中空玻璃微珠(F-HGB),并以HGB、F-HGB为填料制备HGB/PU、F-HGB/PU涂层。通过FTIR、SEM、EDS、接触角测定仪表征HGB表面接枝情况。利用紫外老化装置、氙灯老化箱分别对涂层进行紫外老化和氙灯老化,以涂层的外观、色差和光泽度变化评价玻璃微珠添加量、表面改性对涂层耐老化性能的影响。结果 HGB表面成功接枝含氟树脂。相比于PU、HGB/PU涂层,F-HGB/PU涂层的耐老化性能有较大提高。当F-HGB添加量为20 phr时,F-HGB/PU涂层紫外老化1320 h后,色差为24.38,相比PU、HGB/PU涂层分别降低了48.03%、12.21%,光泽度为49.2,相比PU、HGB/PU涂层分别提升了11.58%、5.70%。氙灯老化360个循环后,色差为18.82,相比PU、HGB/PU涂层分别降低了37.62%、20.05%,光泽度为48.6,相比PU、HGB/PU涂层分别提升了7.52%、7.76%。结论表面接枝含氟树脂改性中空玻璃微珠具有良好的耐老化性能,可作为功能填料提高聚氨酯涂料的耐老化性能。

Effect of HGB Grafted Fluororesin of Surface on Aging Resistance of Polyurethane Coating

The work aims to improve the aging resistance of polyurethane (PU) coating by modifying hollow glass beads with fluororesin through the surface grafting method. The hollow glass beads were respectively treated in NaOH solution, KH550, HDI and fluororesin through the surface grafting method. Then, the surface modified HGB was prepared and the HGB/PU and F-HGB/PU coatings were deposited with HGB and F-HGB as fillers. The surface modified HGB was characterized by FTIR, SEM, EDS and contact angle tester. Ultraviolet aging device and xenon lamp aging chamber were used to age the coatings. The effect of glass beads addition and surface modification on the aging resistance of the coatings was evaluated by the changes of appearance, color difference and glossiness of the coatings. Fluororesin was successfully grafted on the HGB surface. Compared with PU and HGB/PU coatings, the aging resistance of F-HGB/PU coatings was improved. When the amount of F-HGB was 20 phr, the color difference of F-HGB/PU coating after UV aging for 1320 hours was 24.38, 48.03% and 12.21% lower than that of PU and HGB/PU coating respectively, and the glossiness was 49.2, 11.58% and 5.70% higher than that of PU and HGB/PU coating respectively. After 360 cycles of xenon lamp aging, the color difference of the same F-HGB/PU coating was 18.82, which was 37.62% and 20.05% lower than that of PU and HGB/PU coating respectively, and the glossiness was 48.6%, which was 7.52% and 7.76% higher than that of PU and HGB/PU coating respectively. F-HGB has good aging resistance and can be used as a functional filler to improve the aging resistance of PU coating.