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林业科学 ›› 2017, Vol. 53 ›› Issue (2): 100-109.doi: 10.11707/j.1001-7488.20170212

• 论文与研究报告 • 上一篇    下一篇

预处理竹材的结晶度分析

楚杰, 张军华, 马莉, 路海东   

  1. 西北农林科技大学 杨凌 712100
  • 收稿日期:2015-12-09 修回日期:2016-10-31 出版日期:2017-02-25 发布日期:2017-03-23
  • 通讯作者: 张军华

Study of the Crystallization Parameters of Bamboo Fibers with Pretreatment

Chu Jie, Zhang Junhua, Ma Li, Lu Haidong   

  1. Northwest Agriculture and Forestry University Yangling 712100
  • Received:2015-12-09 Revised:2016-10-31 Online:2017-02-25 Published:2017-03-23
  • Supported by:
    Shaanxi Science and Technology Research Project (2014 k02-12-04); Basic Science and Technology Found of North West Agriculture and Forestry University (2452015165).

摘要: [目的] 化学预处理是生物质聚合物产品高值化利用的关键步骤,阐明预处理机制有助于提高热处理效率。[方法] 以4年生毛竹为研究对象,采用稀酸、碱、甘油分别在117℃和135℃进行砂浴预处理,并采用光谱和湿化学方法对预处理前后样品的结构进行表征和比较,包括傅里叶红外光谱、聚合度、X射线衍射等。[结果] 综纤维素和纤维素的产量显著增加,碱(NaOH)预处理比稀硫酸(H2SO4)和甘油(丙三醇)脱木素效果好;在相同预处理条件下,135℃比117℃样品的结构变化更明显。平均聚合度结果显示,所有预处理样品均表现出较低的聚合度,说明纤维素结晶区尺寸发生变化,部分木质素和半纤维素降解,从而增加可及度。X射线衍射结果表明,002峰位置明显偏移,晶体宽度和半峰宽下降,不同化学预处理后的结晶强度明显增加,相对结晶度在117℃下降,在135℃逐渐恢复,傅里叶红外光谱与X射线衍射研究结果一致。[结论] 无论采用117℃还是135℃砂浴预处理,碱预处理纤维分离的效果均强于稀酸和甘油,可为后续木质纤维素原料水解和能源化转换方面的相关研究提供基础和依据。

关键词: 竹材, 预处理, 傅里叶红外光谱, 平均聚合度, X射线衍射, 热重分析

Abstract: [Objective] Chemical pretreatment is a critical step for transforming a biomass to its value-added lignocellulosic biomass polymeric products, and the elucidation of pretreatment mechanism is important for improving the thermal treatment efficiency.[Method] Four-year-old bamboo was pretreated with acid, alkali and glycerine at 117℃ and 135℃,respectively. The structural features of the pretreated and the native samples were characterized and compared using a set of spectroscopy and wet chemistry methods including FTIR, XRD,respectively.[Result] The results showed that the holocellulose and cellulose yields increased significantly, and the lignin removal rate was better for dilute alkali (NaOH) pretreatment than that for dilute acid (H2SO4) and glycerin pretreatments. Furthermore, for the same solutions, the compositional changes of samples were more remarkable at 135℃ than those at 117℃, and the same degradation of hemicelluloses was observed for different processing.All of the pretreatment samples exhibited relatively low average degree of polymerization (DP) values, indicating that the pretreatment processing could change the super molecular structure.The X-ray diffraction results showed that after different chemical heat treatments, the 002 peak position was clearly offset, the crystalline width and half peak width decreased, but the crystalline intensity increased significantly, and the relative crystallinity declined at 117℃ and gradually increased at 135℃. The results obtained by Fourier infrared spectrum were consistent with those of the X-ray diffraction.[Conclusion] For both 117℃ and 135℃ pretreatment temperature in sand bath, alkali pretreatment effects were stronger than that of the dilute acid and glycerin. These results would provide foundation and basis for the research of energy transformation of lignocellulose raw material.

Key words: bamboo, pretreatment, Flourier infrared spectrum, average degree of polymerization, X-ray diffraction, thermogravimetric analysis

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