Tensile Properties of Single Rattan Fibers

The longitudinal tensile strength of single fibers of four rattan species, namely C. simplicifolius, C. nambariensis Becc. var. yingjiangensis, C. nambariensis var. xishuangbannaensis, and C. yunnanensis, was studied using a custom-built short vegetable fiber mechanical tester. The stress-strain curves produced by the four different rattans showed two distinct phases: a steep, straight segment in the initial phase followed by a straight line with a lower slope up to the breaking point. The respective average values for tensile elastic modulus, tensile strength, and elongation at breaking point of C. simplicifolius, C. nambariensis.var. xishuangbannaensis, C. yunnanensis, and C. nambariensis var. yingjiangensis canes were 10.61, 10.05, 9.10, and 9.54 GPa; 603, 566, 464, and 539 MPa; and 17.00, 17.24, 16.44, and 21.08%. The length position of the single fibers in the cane had variable effects on the three aforementioned properties for all four sampled rattan species. The tensile properties of C. simplicifolius fibers were highest. Compared with wood and bamboo, modulus of elasticity and tensile strength of the studied rattans were much lower, whereas elongation at breaking point of single rattan fibers was generally higher

Comparative Properties of Bamboo and Pine Pellets

Bamboo is a biomass material that has great potential as a bioenergy resource of the future. To the best of our knowledge, there is a lack of sufficient information concerning bamboo pellets. Bamboo and pine pellets were therefore manufactured using a laboratory pellet mill. This study was carried out to compare and evaluate the properties of bamboo and pine pellets as biomass solid fuels. Bamboo pellets exhibited better combustion properties except for inorganic ash and worse overall physical properties than pine pellets. Most properties of both pellets were improved through carbonization treatment except for bulk and particle density. The properties of all pellets determined in this study met the requirements of Pellet Fuels Institute standards except for bulk density of bamboo pellets, and the gross calorific value also met the minimum requirement for producing commercial pellets of DIN 51731 (>17,500 J/g) (1996). The information from this study is helpful for evaluating properties of bamboo pellets and developing and using bamboo resources

Predicting Density and Moisture Content of <i>Populus xiangchengensis</i> and <i>Phyllostachys edulis</i> using the X-Ray Computed Tomography Technique

Abstract Density (D) and moisture content (MC) are two important physical properties of wood and bamboo, which are highly correlated with many other physical and mechanical properties. In this study, the X-ray computed tomography (CT) technique was used to determine the D and MC of poplar (Populus xiangchengensis) and bamboo (Phyllostachys edulis). There was a statistically significant difference in the CT-measured numbers for D and MC between these species. The D-CT and MC-CT linear models for both species were independently established: Dpoplar = 0.00098 × H + 1.02603, Dbamboo = 0.00118 × H + 0.98684, MCpoplar = 0.00309 × H + 1.89982, and MCbamboo = 0.00131 × H + 0.31488, where H is the CT number. The determination coefficients, R2, of the models were all higher than 0.97. Additionally, the R2 values obtained for model validation were also all higher than 0.97. These results indicated that it is feasible to reliably determine D and MC of wood and bamboo using the X-ray CT technique. This study aims to provide reference data for CT detection of the D and MC of wood and bamboo.</jats:p

Variation in Tensile Properties of Single Vascular Bundles in Moso Bamboo

Abstract Moso bamboo (Phyllostachys edulis), an apt example of an anisotropic, functionally graded composite material, is the most important commercial bamboo species of China. This species has excellent mechanical properties due to its unique vascular bundle structure. This article examines the variation in mechanical properties of single vascular bundles with respect to their location within a bamboo culm. The mechanical exfoliation method was used to prepare the single vascular bundle. This study found that moso bamboo has superior stiffness and strength. Additionally, the variation in properties was large in the radial direction but minimal in longitudinal direction. The large variation in mechanical properties of vascular bundles can be ascribed to the synergistic effect of the fibrous sheath and parenchyma rather than to changes in fibrous sheath properties. This study provides a basis for the structure application for moso bamboo.</jats:p

DYNAMIC MECHANICAL THERMAL ANALYSIS OF MOSO BAMBOO (Phyllostachys heterocycla) AT DIFFERENT MOISTURE CONTENT

Bamboo is a type of biomass materials that has great potential as a bio-energy resource in China. The thermal-mechanical behavior of bamboo plays an important role in the formation process of pellets. To investigate the effect of moisture content (MC) on thermal-mechanical behavior of bamboo, the storage modulus and loss factor of moso bamboo was determined using dynamic mechanical thermal analysis (DMTA) from -50 to 150 oC. The experimental results showed that the general feature of bamboo thermal-mechanical properties with temperature is similar to other cellulosic materials, and they are affected by MC. A substantial decrease of storage modulus over the entire temperature range implies that bamboo underwent a glass to rubber transition. Bamboo, at lower MC, has a higher storage modulus, which decreases the mechanical strength of pellets. The loss factor exhibited two major transitions for all samples. There was an α-transition (α1), attributed to glass transition of lignin, peaking in a higher temperature range. The second major relaxation (α2), located in a lower temperature range, was attributed to glass transition of hemicelluloses. Activating lignin and hemicelluloses using moisture and temperature in the temperature range of glass transition can be very helpful to achieve durable particle-particle bonding

Mechanical Properties of Moso Bamboo Treated with Chemical Agents

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