Mechanical properties of moso bamboo treated with chemical agents

Abstract

Bamboo is a type of biomass material and has great potential as a bioenergy resource for the future in China. Surface chemical and thermal–mechanical behavior play an important role in the manufacturing process of bamboo composites and pellets. In this study, moso bamboo was treated by sodium hydrate solution and acetic acid solution. Surface chemical and dynamic mechanical properties of bamboo were determined using Fourier transform infrared spectroscopy and dynamic mechanical thermal analysis, respectively. Results showed that the main polar chemical groups of the outer layer of bamboo (OB) included hydroxyl group (O-H) and ester carbonyl (C=O). Some new polar chemical groups appeared on the inner layer of the bamboo surface (MB) such as aromatic ethers (C-O-C) and phenolic hydroxyl (C-O). The chemical group difference of OB and MB confirms that there was a waxy layer on the OB surface. Nonpolar chemical groups decreased and polar chemical groups increased on the OB surface when it was treated by acetic acid solution. The waxy layer of the OB surface was removed and the lignin structure was also destroyed by sodium hydrate solution. The general feature of thermal–mechanical properties with temperature was similar to cellulosic materials for OB, OB-NaOH (OB treated by sodium hydrate solution), and OB-acetic (OB treated by acetic acid solution). A lower storage modulus of OB-NaOH and OB-acetic was helpful to improve physical properties of bamboo pellets. There was an α transition (α₁) peaking at about 65°C for OB. The second major relaxation (α₂) occurred at 35°C. The α₁ and α₂ transition temperature of OB changed when it was treated by chemical agents. This information is very important for using bamboo to manufacture composites and pellets.

Citation

Fei, Benhua; Liu, Zhijia; Jiang, Zehui; Cai, Zhiyong. 2013. Mechanical properties of moso bamboo treated with chemical agents. Wood and Fiber Science, Volume 45, Number 1, 2013; pp. 34-41.