酚醛泡沫塑料的受热过程

Heating Procedure of Phenolic Foam

酚醛泡沫塑料热解过程分为3个阶段,第一阶段:室温～196.4℃,失重8.939%,第二阶段:196.4～276℃,失重9.983%,第三阶段:276～619.1℃,失重66.463%。TG/DTG分析同时给出了起始分解温度、最大反应速率的温度等特征温度点。受热影像分析表明:材料在240～900℃间发生收缩变形,累积高度收缩32.420%,体积收缩约60.271%,受热过程无液相产生。在受热后,材料的氧指数随受热温度升高而下降,同一温度下随时间延长而略有降低;材料热值在室温～600℃下降一半,600～700℃迅速降至2.188 MJ/kg。

The pyrolysis of PF could be divided into three stages,its mass loss was 8. 939 % in the first stage from room temperature to196.4 ℃ ,then was 9.983 % between 196.4 ℃ and 276 ℃ ,the third stage from 196.4 ℃ to 276 ℃ was the main stage with the mass loss of 66. 463 %. The characteristic temperature points included initial decomposition temperature and maximum reaction rate temperature of the phenolic foam（PF） were analyzed by TG/DTG. The sintering image indicated that the height contraction and volume contraction occurred between 240 ℃ and 900 ℃ were 32.42 % and 60. 27 % respectively,and liquid phase could not be found during the heating process. The oxygen index of PF decreased with increasing temperature ,and reduced slightly at the same temperature when time extended. The calorific value halved from the room temperature to 600 ℃ ,and decreased rapidly to 2. 1877 MJ/kg between 600 ℃ and 700 ℃.