沙柳木粉液化残渣的结构表征

Structure and Characterization of Residues of Salix Liquefaction

以多元醇为液化剂(m(聚乙二醇)∶m(丙三醇)=4∶1),浓硫酸为催化剂,对沙柳木粉进行液化试验。将所得的液化产物多次清洗得到不溶液化残渣,应用FTIR、XRD和SEM对液化残渣的化学成分、微观形貌进行表征研究。结果表明:沙柳木粉液化反应分为木粉分解阶段和液化产物缩聚两个阶段;反应30 min后得到的残渣的红外光谱特征峰大致相同。XRD分析表明,残渣中含有大量的Si O2,木粉液化时非结晶区首先被破坏而降解,残渣的结晶度升高;反应后期结晶区发生降解,残渣结晶度略有下降。SEM图像表明,随着反应的进行,残渣由纤维状变为尺寸更小的连在一起的块状堆积物。

Salix flour was liquefied with polyols（mixture of polyethylene and glycol） using sulfuric acid as catalyst.The liquefied products were washed for many times to get the insoluble residues.The chemical component and micro-structure of the liquefied residues were measured through FTIR,XRD and SEM.The Salix liquefaction reaction was divided into two phases,including wood powder decomposed reaction and liquefied products condensation reaction.The absorption characteristic peaks of residues were almost the same after 30-min reaction.The crystallinity of residues was increased as the amorphous region was first destroyed when wood was liquefied.The crystallinity was decreased with the degradation of crystalline region in the later stage.SEM photographs indicated that the structure of residues was changed from fibrillar structure to smaller size debris with the increasing of reaction time.