炭化过程中预氧化PAN纤维的热分析

THERMAL ANALYSIS OF PREOXIDIZED PAN FIBERS DURING CARBONIZATION

本文通过模拟炭化温度对预氧化PAN纤维进行了DTA和TG研究。实验结果表明,根据DTA和TG曲线。可将炭化分为三个温度区,即,Ⅰ区(300～450℃):Ⅱ区(450～900℃);Ⅲ区(900～120℃)。炭化升温速率对DTA和TG有较大影响。利用不同升温速率下的DTA和TG曲线,可以计算出预氧化PAN纤维在炭化三个温区中的表观活化能,其值分别为39.76,53.69和49.70kcal/mol。

DTA and TG studies of preoxidized PAN fibers have been made during the carbonization temperature region(300 to 1200℃). The results show that carbonization can be divided into three temperature regions, i, e., 300 to 450℃, 450 to 900℃ and 900 to 1200℃, depending on DTA and TG curves. The rate of heating has been found to kave a big effect on the curves of DTA and TG. The apparent activation energies of three carbonization temperature regions can be calculated from DTA and TG curves made in different heating rates. The values are 39.76, 53.69 and 49.70 kcal/mol. respectively.