低温NaOH溶液中低聚合度纤维素的溶解与析出

采用浓度为9%的NaOH溶液在低温条件下对木浆纤维素进行润胀溶解,分别测定原料和不溶纤维素的R-10值、聚合度,并采用红外光谱(FTIR)、扫描电镜(SEM)、热重(TG)以及X-射线衍射(XRD)方法对原料、不溶纤维素和水析出纤维素进行表征。结果表明低温有利于纤维素在NaOH溶液中的溶解,且在实验设计的范围内温度越低,低聚合度纤维素溶解得越多。与原料和不溶纤维素相比,水析出纤维素的热稳定性稍差。低温条件下,纤维素I晶型易转变为纤维素II晶型,同时析出纤维素也表现出纤维素II晶型。析出纤维素表面孔隙多、表面积大,有可能制备成吸附、隔音或保温材料。

Dissolution and Regeneration of Cellulose with Low DP in NaOH Solution at Low Temperatures

9% NaOH solution was used to swell and dissolve wood pulp cellulose at low temperatures.R-10 and DP of raw material and undissolved cellulose were determined.The raw material/undissolved and regenerated cellulose(adding water to separate out) were respectively characterized by FTIR、SEM、TG and XRD.It turned out that at low temperature NaOH solution had the stronger dissolving ability to cellulose.What’s more,in the design scope the temperature is lower;the dissolution radio of cellulose with low DP is bigger.The thermo stability of regenerated cellulose is not good as raw material and undissolved cellulose.At low temperature,the cellulose crystal is changed from crystal I to crystal II.At the same time,the cellulose crystal of regenerated cellulose also shows crystal II.The regenerated cellulose has large surface areas,so it probably can be made as absorbing/sound proofing/ thermal insulation material.