Microcrystalline cellulose (MCC) has a wide range of applications in food, chemical, pharmaceutical industries, etc. In this study, the one-step preparation of MCC from bleached Kraft bamboo pulp (BKBP) by extremely low acid (ELA; acid concentration ≤0.1 wt %) was demonstrated. The experimental data indicate that the crystallinity, degree of polymerization (DP), and yield of MCC were strongly affected by the time and temperature of hydrolysis, as well as the concentration of hydrochloric acid (HCl). Rod-like MCC was obtained with a yield of 76.4% (based on the mass of original BKBP) and exhibited high crystallinity and narrow particle diameter distribution (78.7%, 30–70 μm) under optimal conditions (acid concentration of 0.08 wt%, 165 °C, 40 min). The Fourier transform-infrared spectroscopy (FTIR) and X-ray diffraction (XRD) measurements showed that the resulted MCC maintained cellulose I structure. Thermal analysis demonstrated that the as-prepared MCC exhibited good thermal stability. The ELA hydrolysis process may provide a green alternative for the manufacture of MCC from bleached Kraft bamboo pulp.

中文翻译：

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极低酸水解竹浆微晶纤维素的分离与表征

微晶纤维素（MCC）在食品、化工、医药等行业有着广泛的应用。本研究以漂白牛皮纸竹浆（BKBP）为原料，采用极低酸（ELA；酸浓度≤ 0.1 重量％) 被证明。实验数据表明，MCC的结晶度、聚合度（DP）和产率受水解时间和温度以及盐酸（HCl）浓度的强烈影响。在最佳条件下（酸浓度为 0.08 wt%，基于原 BKBP 的质量），获得了棒状 MCC，收率为 76.4%，并表现出高结晶度和窄粒径分布（78.7%，30-70 μm）。 165 °C，40 分钟）。傅里叶变换红外光谱 (FTIR) 和 X 射线衍射 (XRD) 测量表明所得 MCC 保持了纤维素 I 结构。热分析表明，所制备的 MCC 表现出良好的热稳定性。ELA 水解工艺可以为用漂白的牛皮纸竹浆制造 MCC 提供一种绿色替代方案。