聚甲醛耐候性研究

研究了自然老化和人工加速老化试验中聚甲醛力学性能的变化规律，考察了人工加速老化与自然老化试验的相关性。结果表明：光、热、水的综合作用是造成聚甲醛力学性能显著下降的主要原因；聚甲醛的断裂伸长率和缺口冲击强度对材料老化十分敏感，老化初期就显著下降；热老化无法模拟自然老化中聚甲醛力学性能变化规律，而试验中紫外灯光老化所采用的试验条件可模拟海拉尔、苍山等自然环境条件下聚甲醛力学性能变化规律，但对海南、广州等具有强日照、高温、高湿、多雨的自然环境模拟效果不好。

Research on Weatherability of Polyoxymethylene

Natural and artificial accelerated weathering tests were employed to study the change of mechanical properties of POM.The correlation of natural and artificial accelerated weathering tests was investigated.The results showed that the main reason caused sharply decline of mechanical properties of POM was integrated action of light,heat and water.Elongation at break and impact strength were sensitive to weathering of material and declined sharply in the early stage of weathering.The change of mechanical properties of POM in natural weathering couldn't be simulated by thermal weathering test. The change of mechanical properties of POM exposed in Hailaer and Cangshan could be simulated by UV weathering test using conditions of this work,but UV weathering test of this work couldn't be used to simulate natural weathering of Hainan and Guangzhou which has strong solar radiation,high temperature,high humidity and raininess.