核桃壳纤维素液化的研究

Study on Liquefaction of Cellulose of Walnut Shell

以残渣率、游离酚含量和可被溴化物含量为指标,采用傅里叶红外光谱(FTIR)和凝胶渗透色谱(GPC)为分析手段,研究了酸催化条件下苯酚液相中核桃壳纤维素的液化.结果表明:核桃壳纤维素在酸性条件下苯酚液相中的液化实质上是纤维素的缓慢降解过程,在纤维素分子链降解为低聚糖等低分子物的同时,可能存在葡萄糖吡喃环的开环反应;在液化残渣率降低、纤维素分子量大幅下降的同时,伴随着液化中间产物与苯酚的反应,生成可溶于苯酚液相的液化产物,并使液化体系游离酚含量和可被溴化物含量降低.

By means of FTIR and GPC,the liquefaction of cellulose from walnut shell under acid catalysis condition in the presence of phenol was discussed by taking the residue content,contents of free phenol and brominable substance as indices.The results showed that the liquefaction process of cellulose from walnut shell in the presence of phenol under acid condition was essentially a slow degradation process of cellulose.When the cellulose was degraded to low molecular fragments such as oligosaccharides,there was possibly the breakage reaction of pyranoid ring simultaneously.When the semi-product from cellulose liquefaction reacted with phenol,the liquefied product,which could be dissolved in phenol,was formed and the content of free phenol and brominable substance decreased along with the reduction of residue and molecular weight during liquefaction.