玉米皮纤维素提取工艺优化及结构表征

在单因素实验的基础上,运用响应面法对玉米皮纤维素的提取工艺进行优化,并利用扫描电镜、傅里叶变换红外光谱仪、X-射线衍射仪和热重分析仪对玉米皮纤维素的微观形貌、化学结构、晶型结构及热稳定性进行表征。结果表明,最优工艺条件为料液比1:20 g/mL、提取温度96 ℃、提取时间2.6 h、硝酸体积分数27%,此条件下提取物纤维素含量为80.26%±0.88%。表征结果表明,玉米皮半纤维素和木质素得到有效去除,玉米皮纤维素结构没有受到破坏;玉米皮纤维素晶型未改变,仍为I型,结晶度为56%;玉米皮纤维素热分解起始温度222 ℃,热稳定性优于玉米皮。优化的玉米皮纤维素提取工艺可行,在工业上有广阔的应用前景。

Optimization of Extraction Technique and Structure Characterization of Cellulose from Corn Bran

On the basis of single factor experiments, the extraction process of corn bran cellulose was optimized by response surface methodology. The microscopic morphology, chemical structure, crystal structure and thermal stability of corn bran cellulose were respectively characterized by SEM, FTIR, XRD and TGA. The results showed that, the optimal conditions were the solid/liquid ratio 1:20 g/mL, extraction temperature 96℃, extraction time 2.6 h, HNO₃ volume fraction 27%. Under these conditions, the content of cellulose extracted from corn bran was 80.26%±0.88%. The results of characterization by SEM, FTIR, XRD and TGA showed that hemicellulose and lignin were effectively removed from corn bran;the crystalline form of corn bran cellulose remained unchanged and remained I type, the crystallinity was 56%;the thermal decomposition starting temperature was 222℃, and thermal stability was better than corn bran. The optimized corn bran cellulose extraction process was feasible and had broad application prospects in industry.