共查询到19条相似文献,搜索用时 672 毫秒
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对于PVC涂层朦结构材料光氧老化的各种不同老化试验方法(自然老化和人工加速老化)进行了系统性的介绍,针对不同试验方法给出其对应的相关参考标准;从宏观和微观两方面对老化表征方法进行了详细介绍,最后分析了膜结构材料老化研究现有不足及未来研究前景。 相似文献
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通过红外光谱、色差和力学性能等研究了丙烯腈–丁二烯–苯乙烯塑料(ABS)在人工加速老化试验(UVA,UVB和氙灯)及户外自然老化试验过程中老化行为的相关性。红外分析结果表明,不同ABS材料在人工加速老化和自然老化过程中遵循相同的光氧老化动力学,但不同光源对ABS材料的加速老化作用有明显差别;色差分析结果表明,人工加速老化试验对色差变化的加速倍率由大到小顺序为:UVBUVA氙灯。通过分析ABS材料的色差及力学性能在人工加速老化与户外自然老化过程中变化的相关性,拟合了人工加速老化与户外自然老化的时间换算方程。 相似文献
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与其他发达国家相比,中国的建筑膜材料发展起步较晚,但作为一种新兴材料,近年来在建筑中广泛运用,发展速度快,被称为"第五代建材"。本文简要介绍了建筑膜材的研究背景、现状和性能,并比较了PVC与PTFE性能的优越性;介绍了建筑膜材自然老化和人工加速老化的试验方法和相关标准。对既有建筑拆除下来的两种膜材进行了黄度指数测试实验、扫描电镜实验、接触角测试实验和单轴拉伸实验。提出尚需进一步解决的问题;最后对建筑膜材老化及其性能退化研究进行了展望,指出深入研究建筑膜材的老化及膜结构性能退化的意义。 相似文献
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对建筑外墙涂料在自然曝晒场进行自然曝晒试验,并同时在实验室中进行人工加速老化试验,通过考察涂层光学性能随老化时间的变化规律,统计分析自然气候曝晒试验和人工加速老化试验的数据结果,研究人工加速老化试验模拟自然气候曝晒试验的相关性,探讨涂料使用寿命的推算。 相似文献
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LDPE农用耐候棚膜专用料的配方研究及工业化生产 总被引:1,自引:0,他引:1
研究了LDPE农用聚乙烯耐候棚膜专用料的配方及老化问题,介绍了选用母粒掺混法制备专用料的工艺路线。经人工加速老化和扣棚自然老化试验证明,用该专用料吹制的棚膜,其使用寿命可达1.5~2年,比普通膜寿命长3~4倍。 相似文献
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ABS颜色稳定性的老化试验 总被引:2,自引:1,他引:2
未稳定和经稳定ABS的人工加速老化试验。自然大气暴露试验和透过窗玻璃暴露试验。通过颜色和变黄指数变化评价ABS的颜色稳定性,结果表明;人工加速老化与自然大气暴露有较好的相关性。加速倍率约为7;添加稳定体系能有效地抑制ABS的变黄。并观察到ABS在老化过程中的变白与变黄现象。 相似文献
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:将加入了防老化母粒的聚丙烯高强丝进行人工加速老化试验和户外大气暴露试验,讨论了防老化母粒在高强丝上的应用。结果表明:添加2%的防老化母粒,经1年的户外大气暴露试验,聚丙烯高强丝的断裂强度保持率高达80.2%,断裂伸长保持率达79.0%;而未加防老化母粒的聚丙烯高强丝,户外暴露5个月,断裂强度保持率降至46.7%,断裂伸长保持率降至36.4%。同时还对添加防老化母粒与使用耐候级聚丙烯专用料的耐候性、不同母粒添加量的耐候性做了对比。 相似文献
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通过一年的自然大气曝露试验和1000小时氙灯人工加速老化试验,对经稳定的ABS、ABS/PVC合金、耐候ASA老化前后的颜色变化和悬臂梁缺口冲击强度保持率进行比较,可以得出结论:ABS/PVC合金的耐候性能与经稳定ABS相比有大幅度提高;在一定时间内,颜色稳定性和悬臂梁缺口冲击强度保持率与ASA相近。 相似文献
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功率型LED有机硅封装材料的耐老化性能研究 总被引:1,自引:0,他引:1
采用氙灯人工加速老化及热空气加速老化的方法,研究了以聚硅氧烷为主要原料制备的用于功率型LED的有机硅封装材料的耐热及耐候性能。结果表明:制备的树脂型4265及橡胶型4150两种有机硅封装材料的透光率较高,均在92%左右;二者耐热老化性能优异,适用于功率型发光二极管(LED)的封装;相比较而言,树脂型4265的耐候性能较好,更适合户外使用。 相似文献
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Adhesive bonding is often the most desirable joining method in terms of structural efficiency and cost and is being used in an increasing number of civil and military applications. One of the main stumbling blocks to the further use of adhesive bonding is the lack of confidence in long-term durability, particularly in humid environments. When designing bonded joints, the effect of ageing is usually accounted for by subjecting the joints to artificially high levels of loading or extreme environmental conditions for short times prior to testing. However, the relationship between the results from these accelerated tests and actual long-term ageing is poorly understood. The Defence Evaluation and Research Agency (DERA) has what is probably a unique set of experimental data for a wide range of adhesively-bonded joints subjected to both accelerated ageing in the laboratory and long-term outdoor exposure. In this paper the relationship between the naturally aged and accelerated aged joints is explored. It is concluded that no simple correlation can be made between joints aged in different environments. The best that accelerated ageing can achieve is to eliminate those adhesives likely to perform badly in conditions of high humidity and to indicate those systems likely to perform well. 相似文献
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Adhesive bonding is often the most desirable joining method in terms of structural efficiency and cost and is being used in an increasing number of civil and military applications. One of the main stumbling blocks to the further use of adhesive bonding is the lack of confidence in long-term durability, particularly in humid environments. When designing bonded joints, the effect of ageing is usually accounted for by subjecting the joints to artificially high levels of loading or extreme environmental conditions for short times prior to testing. However, the relationship between the results from these accelerated tests and actual long-term ageing is poorly understood. The Defence Evaluation and Research Agency (DERA) has what is probably a unique set of experimental data for a wide range of adhesively-bonded joints subjected to both accelerated ageing in the laboratory and long-term outdoor exposure. In this paper the relationship between the naturally aged and accelerated aged joints is explored. It is concluded that no simple correlation can be made between joints aged in different environments. The best that accelerated ageing can achieve is to eliminate those adhesives likely to perform badly in conditions of high humidity and to indicate those systems likely to perform well. 相似文献
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聚酯纤维/PVC柔性复合材料由于多用于户外,易受阳光照射而老化,从而影响材料的力学性能。通过模拟大气环境较好的氙灯耐气候试验箱,考察了氙灯加速老化对聚酯纤维/PVC柔性复合材料顶破性能和撕裂性能的影响。采用CRT材料试验机,研究了聚酯纤维/PVC柔性复合材料的顶破性能和撕裂性能的变化,并比较了两种不同撕裂模式的破坏机理;采用FTIR研究了PVC涂层吸收峰和峰强的变化;采用SEM研究老化前后涂层表面的微观形貌。研究表明:氙灯人工气候老化下,聚酯纤维/PVC柔性复合材料的老化机理主要是羰基化合物和共轭双键的形成;柔性复合材料撕裂性能下降明显;不同撕裂模式对评价柔性复合材料差异较大。 相似文献
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The natural weathering of electrophoretic coatings exposed to continental weather in Trento (Italy) for about one year was considered. The environmental factors (such as wet time, temperature, and r.h.) affecting the properties of the organic coatings were monitored and investigated to ensure a consistent comparison between the laboratory results and the real weathering of the materials. The properties of the coatings were evaluated also after different laboratory tests using mainly EIS. The effects of the accelerated ageing were compared to the results of the outdoor exposure to get some insight into the understanding of the correlation between indoor and outdoor exposure. 相似文献