木素/聚氧化乙烯碳纤维前驱体的热解动力学

Pyrolysis kinetics of blended lignin/PEO carbon fibers precursors

以N,N-二甲基甲酰胺(DMF)为溶剂,将木素与聚氧化乙烯(PEO)以质量比1∶0、3∶1、1∶1、1∶3配制纺丝液,通过静电纺丝法制备碳纤维前驱体,并通过扫描电子显微镜对4种碳纤维前驱体进行表征。木素与PEO质量比为3∶1时纤维表面光滑,纤维形态最好,质量比为1∶1时不能成纤维。通过热重分析仪,将木素与PEO质量比为3∶1和1∶1的前驱体在10、20和40℃/min升温速率下进行热解,利用Kissinger-Akahira-Sunose(KAS)和Flynn-Wall-Ozawa(FWO)模型分析转化率随温度的变化情况,并计算碳纤维前驱体热解的活化能。结果显示,木素与PEO质量比为3∶1的前驱体热解速率大于质量比为1∶1的前驱体,热解过程更符合FWO模型,且随着木素含量的增加,热解活化能降低。

Blended lignin/PEO carbon fibers precursors with weight ratios of 1：0,3：1, 1：1 and 1：3 were fabricated by electrospinning using DMF as solvent. The morphology of prepared precursor was characterized by SEM. The precursors with weight ratio of 3：1 represented the best morphology and the precursors with weight ratio of 1：1 represented morphology of particle. The precursors with weight ratios of 3：1 and 1：1 were pyrolyzed with a controlled heating rate of 10, 20 and 40 ＊C/rain in the TG analyzer. The variation of conversation ratio with temperature was studied by Kissinger-Akahira-Sunose （KAS） and Flynn-Wall-Ozawa （FWO） models and the activation energy was calculated. The results showed that pyrolysis rate of precursors with weight ratio of 3：1 was faster than that of 1：1. The correlation between the weight loss efficiency and temperature was