-
测量了高聚物材料聚丁二烯的比热,发现在温度Tg=178K出现玻璃转变且转变点附近的比热与降温过程有关。在降温过程中,若控制样品在某一温度Twg等待时间tw,则升温比热测量表明,Tg处的比热跃变△cp存在明显的等待时间效应,即△cp随tw的增大而增大。在Tw=169K条件下,△cp(t<The specific heat of polybutadien was measured and it was found that at temperature Tg = 178K there is a glass transition and the specific heat near the transition temperature depends strongly on the cooling process of the sample. After waiting at temperature Tw for a time tw during the cooling process, we found that there are waiting time effects on the specific heat of a heating process: the anomalous Δcp at Tp increases with the waiting time tw. In thecase of Tw=169K, Δcp(tw) can be described by Kohlrausch law Δcp(tw)~{l-exp[-(tw/τ)β]} with β =0.47±0.03.
计量
- 文章访问数: 7059
- PDF下载量: 514
- 被引次数: 0