稻壳/聚乙烯复合材的自然老化与紫外光加速老化

Natural Weathering and Accelerated UV Weathering of Rice-Hull-Polyethylene Composite

对稻壳/聚乙烯复合材的室外自然老化情况进行1年多的观察,并对相同材料进行实验室紫外光(UV)加速老化,研究材料力学性能变化,并通过傅里叶红外波谱(FTIR)分析探讨老化机制,力争寻求二者之间的初步对应关系。自然老化试件在气温较低和日照时间较短的前5个月内(冬季)颜色基本没有变化,经历盛夏之后颜色发生显著变化,变化幅度与实验室加速老化1500h的结果相当。与自然老化相比,加速老化500h后即可明显表现出各种化学特征的变化趋势,但在以后的1500h里没有再发生显著变化;而自然老化12个月后试材表面才有显著化学变化。老化首先使稻壳/聚乙烯复合材的颜色发生较大改变,表面化学性质变化也较早开始,但无论自然老化还是加速老化在短时间内对材料力学性能都不会产生显著影响。

Rice-hull-polyethylene composite samples were natural weathered for one year and same material was accelerated weathered by ultra violet （UV） radiation in laboratory. The authors researched property change and analyzed weathering mechanism by FFIR. The result will help properly evaluate the properties of natural fiber reinforced polymer composite and improve formula. In the first 5 months, there was almost no color change for natural weathering samples because of low temperature and short sun shining time. Experiencing hot summer, color changed significantly and the result was similar to that of 1 500 h accelerated UV weathering. In accelerated ,deathering, the first 500 h was enough to present chemical property change on weathered surface, however, in later 1 500 h changed a little. In natural weathering, 12 months presented obviously surface chemical change. Experiencing weathering, rice-hull-polyethylene composite changed color and surface chemical property earlier. However, both accelerated weathering and natural weathering did not decrease mechanical properties significantly in the short test duration.