聚碳酸酯微孔塑料的动态力学热分析

通过对聚碳酸酯微孔塑料进行动态力学热分析,得到了不同密度微孔塑料动态力学性能的温度图谱和频率图谱,研究了储能模量和损耗因子与温度、频率及密度之间的变化规律和玻璃化转变温度与密度之间的关系.结果表明:在高频或低温时,随着温度的升高,微孔塑料储能模量降低,损耗因子增加;当温度高于材料的玻璃化转变温度或者频率较低时,随着频率的降低和温度的升高,储能模量和损耗因子都急剧地降低;聚碳酸酯微孔塑料的玻璃化转变温度T_g在175°C左右,次级转变在70~100℃之间,结果与密度几乎无关. 

Thermal analysis for dynamic behavior of microcellular polycarbonate

The dynamic behavior of microcellular polycarbonate for different densities at different temperatures and frequencies was investigated by means of dynamic mechanical thermal analysis. The relations of storage modulus and loss factor with temperature, frequency and density were discussed at the same time.Furthermore, the relation of glass transition temperature of microcellular polycarbonate with density was also discussed. The results show that when the microcellular polycarbonate is at high frequency or low temperature, the storage modulus is decreased and the loss factor is increased with increasing temperature. Meanwhile, when the temperature is higher than the glass transition temperature of microcellular polycarbonate or the frequency is very low, the storage modulus and the loss factor are decreased significantly with increasing temperature or decreasing frequency . In addition, the experimental results also show that the glass transition temperature of microcellular polycarbonate is about 175℃ and the secondary transition temperature of microcellular polycarbonate is in the range of 70~100℃, which almost have nothing to do with density.