Chemical-Physical Treatment for Production of Cellulose Nanofiber from Kenaf Bast Fiber

ABSTRACT

This paper presents the isolation of kenaf bast fiber to produce cellulose nanofiber (CNF) using chemical-physical treatment (e.g. delignification, bleaching and ultrasonication). Raw bast fiber was bleached and then subjected to high-intensity ultrasonication at four different output powers (100 W, 200 W, 400 W and 700 W). SEM and TEM analysis of treated bast fiber revealed that the morphological structure of CNF with diameter distribution in the range less than 100 nm (100 W) to 10 nm (700 W). Hemicellulose and lignin content were successfully reduced by chemical treatments, as there was increment of the cellulose content in the fiber more than 90% recorded. Higher ultrasonication output power attributes to the decreasing diameter size of CNF. This finding reflected that smaller CNF fibrils provide larger surface area per volume ratio. Larger stretching vibration of – OH group is detected as the higher composition of cellulose in CNF. CNF produced also had higher thermal stability than raw bast fiber after undergoes the chemical-physical treatment. Therefore, chemical-physical treatment did not only to attribute the success of deposition of lignin and hemicellulose, but also to increase the nano-sized fiber distribution in CNF suspension.

摘要

本文介绍了使用化学物理处理 (例如脱木素, 漂白和超声波处理) 分离洋麻韧皮纤维以生产纤维素纳米纤维 (CNF) 。将粗韧皮纤维漂白并在四种不同的输出功率 (100 W, 200 W, 400 W 和 700 W 下进行高强度超声波处理。 SEM和TEM分析显示CNF的形态结构, 其直径分布在小于100 nm (100 W) 至10 nm (700 W) 的范围内。通过化学处理成功地降低了半纤维素和木质素含量, 因为纤维中纤维素含量增加了90%以上。较高的超声波输出功率归因于CNF的直径尺寸减小。该发现反映了较小的CNF样品每体积比提供较大的表面积。检测到-OH基团的较大拉伸振动是CNF中较高的纤维素组成。所生产的CNF在经过化学 - 物理处理后也具有更高的热稳定性。因此, 化学 - 物理处理不仅归因于木质素和半纤维素沉积的成功, 而且还增加了CNF中纳米尺寸的纤维分布。

KEYWORDS:

• Cellulose nanofiber (CNF)
• chemical-physical treatment
• kenaf bast fiber
• ultrasonication
• delignification
• bleached pulp fiber
• 关键词
• 纤维素纳米纤维 (CNF)
• 化学物理处理
• 洋麻韧皮纤维
• 超声
• 脱木素
• 漂白纸浆纤维

Disclosure statement

There is no conflict of interest.

Additional information

Funding

This work was supported by Ministry of Higher Education Malaysia under UPM Putra Grants: GP/2017/9564100 and GP-IPS/2018/9607700.