高密度聚乙烯/稻壳复合材料老化性能的研究

Study on Aging Performance of HDPE/Rice Husk Composites

研究了放置在室温、阳光曝晒和户外阴面自然环境中的高密度聚乙烯（HDPE）/稻壳复合材料的材色和弯曲疲劳/蠕变性能.结果表明：在阳光和户外阴面自然环境中,该材料的材色变化较大,尤其是前2个月,材料变白变黄,且因潮气致其发霉,6个月后,材料产生的色差△E^＊高达20.64;在阳光和户外阴面自然环境中放置2,4,6个月后,材料的抗弯强度下降3.17%^19.20%,抗弯弹性模量下降3.23%^16.38%,而且其疲劳/蠕变性能也有一定下降;2个月后,材料产生的应变约为室温时的1.1^1.2倍,4个月后,由于温湿度、紫外线和光照强度降低,材料产生的应变减小,6个月后,材料产生的应变反而比室温时小;六元件模型能比四元件模型更好地模拟材料的疲劳/蠕变行为;材料的弹性变形与应力水平无明显关系,其黏弹性变形和黏性变形均随应力水平的增加而增大,且符合时间-温度-应力等效原理.

The color and fatigue/creep behavior of high density polyethylene（HDPE）/rice husk composites at room temperature,under sun exposure and outdoor shade environment were tested.Under sun exposure and outdoor shade environment the color of the surface changes much and especially in first two months; the material turns white and yellow,and△E~＊ is as high as 20.64 after six months.The modulus of rupture （MOR） reduces by 3.17%- 19.20%and the modulus of elasticity（MOE） reduces by 3.23%- 16.38% and the fatigue/creep performance also is a bit declined under sun exposure and outdoor shade environment for 2,4 and 6 months.The strain was about 1.1-1.2 times that of WPC at room temperature after two months and the strain decreases after four months as the temperature and humidity and ultraviolet and light intensity decrease and it is smaller than what is at room temperature after six months.The six-parameter model is better to use for simulating the short-term fatigue/creep behavior of WPC.The elastic deformation has no remarkable relationship with the stress level;viscoelastic deformation and viscous deformation increase with increasing stress level.And the materials obey the time-temperature-stress equivalence principle.