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聚碳酸酯 (PC)物理老化中的二个热流转变现象的研究发现 :sub Tg 热流转变开始于较低温度 ,并随之移向高温 ,最终形成一个转变 .玻璃化转变温度随此前的降温速率而变化 ,并存在一最低点 ,只有老化前的冷却速率高于该速率时 ,样品老化后才会出现sub Tg 热流转变 .同时淬火的起始温度与这一热流转变也有着直接的联系 .这一现象与环氧树脂相似 ,sub Tg 转变可以被归结为内应力已松弛的链段的热运动 .
The study of two heat flux phenomena in the physical aging of polycarbonate (PC) found that the sub Tg heat flux begins with a lower temperature and moves to a higher temperature, which eventually leads to a change.The glass transition temperature decreases with the previous cooling rate , And there is a lowest point, and the sub Tg heat flux transformation will not occur until the sample is aged, and the starting temperature of quenching is also directly related to this heat flux transformation, only when the cooling rate before aging is higher than this rate. A phenomenon similar to epoxy resin, sub Tg transition can be attributed to the relaxation of the internal stress has been the thermal motion of the segment.