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本文利用DSC研究了羟乙基纤维素醋酸酯在不同降温速率下的非等温相转变动力学。发现利用改进的Avrami方程来处理得到其指数n接近于1,表明液晶相是在无热成核以后呈一维方式生长的。相转变速率常数随温度的升高而减小。相转变的半周期t_1/2比大多数高聚物结晶过程的半周期要短,并且随温度的升高而变长。相转变速率最快时的温度随着降温速率的增加而向低温方向位移。同时,在一定降温速率范围内降温速率增加,动力学相转变能力增强。有利于液晶相的形成。
In this paper, the non-isothermal phase transition kinetics of hydroxyethyl cellulose acetate at different cooling rates was studied by DSC. It was found that using the modified Avrami equation to process it, the index n was close to 1, indicating that the liquid crystal phase grew in one dimension without thermal nucleation. The phase transition rate constant decreases with increasing temperature. The half-period t_1 / 2 of the phase transition is shorter than the half-period of most polymer crystallization processes and becomes longer with increasing temperature. When the phase transition rate is the fastest, the temperature is shifted to a low temperature as the cooling rate increases. At the same time, the cooling rate increases at a certain cooling rate and the kinetic phase transition ability increases. Is conducive to the formation of liquid crystal phase.