Cellulose microfibrils: A novel method of preparation using high shear refining and cryocrushing

被引:275
作者
Chakraborty, A [1 ]
Sain, M [1 ]
Kortschot, M [1 ]
机构
[1] Univ Toronto, Fac Forestry, Dept Chem Engn & Appl Chem, Toronto, ON M5S 3B3, Canada
关键词
aspect ratio; cryocrushing; high shear; microfibril; refining;
D O I
10.1515/HF.2005.016
中图分类号
S7 [林业];
学科分类号
0829 ; 0907 ;
摘要
This paper describes a novel technique to produce cellulose microfibrils through mechanical methods. The technique involved a combination of severe shearing in a refiner, followed by high-impact crushing under liquid nitrogen. Fibers treated in this way were subsequently either freeze-dried or suspended in water. The fibers were characterized using SEM, TEM, AFM, and high-resolution optical microscopy. In the freeze-dried batch, 75% of the fibrils had diameters of 1 mum and below, whereas in the water dispersed batch, 89% of the fibrils had diameters in this range. The aspect ratio of the microfibrils ranged between 15 and 55 for the freeze-dried fibrils, and from 20 to 85 for the fibrils dispersed in water. These measurements suggest that the microfibrils have the potential to produce composites with high strength and stiffness for high-performance applications. The microfibrils in water were compounded with polylactic acid polymer to form a biocomposite. Laser confocal microscopy showed that the microfibrils were well dispersed in the polymer matrix.
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页码:102 / 107
页数:6
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