温度对聚合物材料冲击断裂的影响

研究、总结了在相同实验条件下，聚合物材料部击强度随试验温度的变化规律，其可分为４种类型：随试验温度降低，（１）冲击强度逐渐下降；（２）冲击强度先逐渐下降，然后保持恒值；（３）冲击强度先逐渐下降，然后又逐渐升高；（４）冲击强度逐渐升高。同时，还分析了微观断裂机制以及宏观强度、塑料性对它们的影响。

THE EFFECTS OF TEMPERATURE ON POLYMER MATERIALS IMPACT FRACTURE

In this paper, the effects of testing temperature on impact properties of polymer materials has been studied systematicaly. Four different types of variation in impact strength with decreasing testing temperature have been observed: (1) impact strength decreases gradually on the testing temperature range; (2) impact strength first decreases gradually, and come to constant value as the testing temperature pass a critical value ( T b or T g); (3) impact strength first decreases gradually, but increases gradually when the testing temperature pass T b; (4) impact strength increases slowly in a wider temperature range. The nature of these variations is discussed in the view points of micro fracture mechanism and the balaned between strength and plasticity of the materials.