聚丁二烯中的等待时间效应

测量了高聚物材料聚丁二烯的比热,发现在温度T_g=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T_wg等待时间t_w,则升温比热测量表明,T_g处的比热跃变△c_p存在明显的等待时间效应,即△c_p随t_w的增大而增大。在T_w=169K条件下,△c_p(t< 关键词：

WAITING TIME EFFECT IN POLYBUTADIEN

The specific heat of polybutadien was measured and it was found that at temperature T_g = 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 T_w for a time t_w during the cooling process, we found that there are waiting time effects on the specific heat of a heating process: the anomalous Δc_p at T_p increases with the waiting time t_w. In thecase of T_w=169K, Δc_p(t_w) can be described by Kohlrausch law Δc_p(t_w)～{l-exp-(t_w/τ)^β]} with β =0.47±0.03.