The Effect of Co-60 gamma-Irradiation on the Structure and Thermostability of Alkaline Lignin and Its Irradiation Derived Degradation Products

文献类型: 外文期刊

第一作者: Wu, Xiaofen

作者: Wu, Xiaofen;Chen, Liang;Wang, Keqin;Qi, Hui;Deng, Min;Wu, Xiaofen;Chen, Liang;Wang, Keqin;Qi, Hui;Deng, Min;Chen, Jingping;Su, Xiaojun;Liu, Yun;Qin, Wensheng

作者机构:

关键词: Lignin; gamma-Irradiation; Structure; Thermostability; Degradation products

期刊名称:WASTE AND BIOMASS VALORIZATION ( 影响因子:3.703; 五年影响因子:3.624 )

ISSN: 1877-2641

年卷期: 2019 年 10 卷 10 期

页码:

收录情况: SCI

摘要: To elucidate the degradation mechanism of lignin treated by irradiation, alkaline lignin was used as the material treating with different dosage (0, 100, 200, 400, 600, 800, 1000, 1200 kGy). The morphology, molecular weight, structure, thermostability and degradation products of alkaline lignin irradiated by gamma ray were investigated by a set of experiments. The results observed in scanning electron microscopy showed that there were more cracks and small protuberances on the morphological surface of irradiated-lignin in comparison with untreated lignin. The gel permeation chromatography results showed that weight-average molecular weight and number-average molecular weight of lignin decreased from 17829 and 590 Da to 13526 and 444 Da, respectively, when irradiation dose increased from 0 to 1200 kGy. The absorption bands of hydroxyl group at 3237 cm(-1) detected by Fourier transform infrared (FT-IR) analysis decreased with irradiation dose increased from 0 to 1200 kGy. FT-IR and solid state C-13 nuclear magnetic resonance (C-13 CP/MAS NMR) confirmed that benzene ring skeleton structure of lignin disrupted when the absorbed dose was > 800 kGy. Thermogravimetry/differential thermogravimetry curves revealed thermostability and activated energy (E-a) of lignin were slightly decreased after irradiated. The irradiation derived degradation products of lignin were analyzed by gas chromatography and mass spectrometry, indicated presence of 22 aromatic compounds and 18 aliphatic acids. Moreover, the relative peak area of aromatic compounds and aliphatic acids in un-irradiated lignin (0 kGy) were 4.48 +/- 0.42 and 23.81 +/- 1.85%, respectively, and these two types of degradation products reached a maximum of 23.81 and 6.10% at 800 and 1200 kGy, respectively. In summary, the findings in this work provide a basic scientific support on the mechanism of irradiation and full utilization of lignin.

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