金属装饰涂层耐久性评价方法研究

发布时间：2018-01-27 17:42

本文关键词： 金属装饰涂层自然暴露试验综合加速老化试验相关性　出处：《中国建筑材料科学研究总院》2017年硕士论文　论文类型：学位论文

【摘要】：金属装饰涂层兼有装饰性与保护性,在自然暴露使用过程中,受到环境因素影响逐渐老化,导致外观及性能变化。因此,有必要开展一系列的环境试验来评价金属装饰涂层在不同气候环境条件下的耐久性。目前,评价涂层耐久性的试验主要有自然暴露试验和人工加速试验。自然暴露试验数据直观可靠,但试验周期长,而现有的各类金属装饰涂层产品标准的耐久性评价方法多为单一的光老化或盐雾腐蚀试验,不能较好地模拟实际使用环境对涂层的影响。因此,需要寻找适当的综合加速老化试验方法来模拟自然环境条件,为涂层耐久性评价提供合理的方法依据。本课题选择常用的金属装饰涂层中耐久性最好的聚酯和氟碳2大体系共6种涂层作为试验对象,开展了以琼海为主,吐鲁番、沈阳为辅的三地自然暴露试验,分析影响涂层老化的主要环境因素,结合气象数据,由此设计了3种“光老化+盐雾”综合加速老化试验方案,并以氙灯、紫外、盐雾3种单一老化试验作对比,共6种人工加速老化腐蚀试验。从外观形貌、色差、光泽度三个方面评价6种涂层经室内加速试验与琼海自然暴露试验后的老化规律,并采用Spearman秩相关系数法分析室内外试验的相关性,筛选与自然环境试验相关性最优的人工加速老化试验方法。最后,采用拉曼光谱法分析涂层经过优选的人工加速试验后老化机理与自然环境试验后的老化机理是否一致。结果表明:涂层老化的主要形貌特征为变色和失光。高温高湿、高辐照量、腐蚀性离子等环境因素相互影响、协同作用,加速涂层老化,而单一环境因素对涂层老化的影响较小。氙灯光老化试验的加速性最好,模拟性较差。盐雾试验对涂层色差与光泽度值影响不大,加速性最差,外观形貌也与自然暴露试验有较大差异,相关性较差。综合加速老化试验与自然暴露试验结果的相关性均较好。6种涂层在综合加速老化试验“7d氙灯+3d盐雾”循环1的老化过程中,色差与光泽度变化趋势与自然暴露试验结果一致,加速性较好;在色差方面,“7d氙灯+3d盐雾”综合加速老化循环与琼海自然暴露试验相关性系数为0.83,相关性良好;聚酯涂层激光拉曼频谱显示,中红外区涂层颜填料老化降解程度很高,室内外试验老化机理一致。表明“7d氙灯+3d盐雾”综合加速老化试验方案可以作为评价金属装饰涂层耐久性的人工加速老化试验方法。
[Abstract]:Metal decorative coating has both decorative and protective properties. In the process of natural exposure, it is gradually aging due to environmental factors, resulting in changes in appearance and performance. It is necessary to carry out a series of environmental tests to evaluate the durability of metallic decorative coatings under different climatic and environmental conditions. The main tests to evaluate the durability of coating are natural exposure test and artificial accelerated test. The data of natural exposure test are intuitionistic and reliable, but the test period is long. However, most of the existing durability evaluation methods of metal decorative coating products are single light aging or salt spray corrosion test, which can not simulate the effect of actual application environment on the coating. It is necessary to find appropriate comprehensive accelerated aging test methods to simulate natural environment conditions. In this paper, 6 kinds of coatings with the best durability of polyester and fluorocarbon were selected as test objects, and Qionghai was the main test object. The natural exposure test in Turpan and Shenyang was carried out. The main environmental factors affecting the aging of coatings were analyzed. Combined with meteorological data, three comprehensive accelerated aging test schemes of "photoaging salt fog" were designed. Compared with xenon lamp, UV and salt spray, there are 6 kinds of artificial accelerated aging corrosion test. The ageing rule of 6 coatings after indoor accelerated test and Qionghai natural exposure test was evaluated from three aspects of glossiness, and the correlation between indoor and outdoor tests was analyzed by Spearman rank correlation coefficient method. Screening the best artificial accelerated aging test method related to natural environment test. Finally. Raman spectroscopy was used to analyze whether the aging mechanism of the coating was consistent with that of the natural environment after the selected artificial accelerated test. The results showed that the aging mechanism of the coating was the same as that of the natural environment test. The main morphologies of the coating are discoloration and loss of light, high temperature and high humidity. Environmental factors such as high irradiation amount corrosive ions and other environmental factors influence each other synergistically accelerate the aging of the coating while the single environmental factor has little effect on the aging of the coating. The acceleration of xenon lamp photoaging test is the best. Salt spray test has little effect on the color difference and glossiness value of the coating, and has the worst acceleration, and the appearance and appearance of the coating are different from those of the natural exposure test. The correlation between the results of comprehensive accelerated aging test and natural exposure test was better. 6 kinds of coatings were in the aging process of comprehensive accelerated aging test "7 days xenon lamp 3 d salt fog" cycle 1. The change trend of color aberration and gloss is consistent with the results of natural exposure test, and the acceleration is better. In terms of color difference, the correlation coefficient between the comprehensive accelerated aging cycle of 7 d xenon lamp and natural exposure test in Qionghai was 0.83, and the correlation was good. The laser Raman spectrum of polyester coating shows that the degradation degree of coating filler is very high in the middle infrared region. The results show that the comprehensive accelerated aging test scheme of "7d xenon lamp 3D salt spray" can be used as an artificial accelerated aging test method to evaluate the durability of metallic decorative coatings.
【学位授予单位】：中国建筑材料科学研究总院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.4

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