酶解辅助高压均质制备纳米纤维素及其性质表征
Preparation and characterization of cellulose nanocrystals by enzymatic hydrolysis combined high-pressure homogenization
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摘要: 本研究以微晶纤维素为原料,经过超微粉碎预处理后,通过酶解辅助高压均质的方法制备纳米纤维素,研究纳米纤维素的结构和理化性质,并通过扫描电镜、透射电镜、红外光谱、X-射线衍射和热失重分析对纳米纤维素进行表征。结果表明,超微粉碎前处理能使微晶纤维素颗粒大小形状趋于均一化;所制备的纳米纤维素呈束状结构,颗粒直径为1540 nm;纳米纤维素在制备过程中纤维素结构未遭到破坏;纳米纤维素的结晶度为58.1%,仍属于纤维素Ⅰ型;纳米纤维素的起始热分解温度比微晶纤维素的分解温度低,当温度达到500℃时,纳米纤维素的热失重率为82.9%。因此通过酶解辅助高压均质制备的纳米纤维素有望在可降解复合材料中得到应用。Abstract: In this study, cellulose nanocrystals were prepared from microcrystalline cellulose.It used enzymatic hydrolysis and high-pressure homogenization to process cellulose nanocrystals which was firstly pretreated by ultrafine grinding. Besides, the structure and physico-chemical properties of cellulose nanocrystals was investigated. The obtained cellulose nanocrystals were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermo gravimetric analysis.The results showed that ultrafine grinding made its particles and shape tend to uniform and did not change the property of the microcrystalline cellulose.The nanocrystals were rod-shaped, with a diameter ranging from 15 to 40 nm.During the preparation of cellulose nanocrystals, the cellulose structure had not been destroyed. The molecular cellulose type I crystalline structure remained intact while the crystallinity was 58.1%. The initial decomposition temperature of cellulose nanocrystals was lower than microcrystalline cellulose.The lost weight of cellulose nanocrystals was82.9% when the temperature reached 500 ℃.The cellulose nanocrystals that prepared from enzymatic hydrolysis and high-pressure homogenization have potential application in biodegradable composites.
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