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Tensile properties of bamboo fiber (BF)/polypropylene (PP) composites were investigated for different impregnation modification processes. The surface morphology of BF and the fracture morphology of the BF/PP composites were examined by scanning electron microscopy (SEM). Images showed that CaCO3 nanoparticles (nano-CaCO3) adhered to the fiber surfaces. Tension tests of individual bamboo fibers (IBFs) and the BF/PP composites were conducted. The results indicated that the tensile strength (TS), modulus of elasticity (MOE), and elongation at break (EAB) of IBFs increased by 16.0%, 22.2%, and 5.2%, respectively, while those of the BF/PP composites increased by 3.0%, 7.0%, and 15.8%, respectively, compared to the control samples. Various process parameters during the impregnation with nano-CaCO3 had marked effects on the tensile properties of the composites. The optimal conditions for BF-reinforced PP composites by impregnation modification were determined to be a nano-CaCO3 concentration of 1.0×10-2 g/mL, an ethylenediamine tetraacetic acid disodium salt (EDTA-2Na) additive concentration of 8.5×10-4 g/mL, and an impregnation time of 25 min.

To blaze new trails for utilizing forestry processing residue, higher plant content biocomposites were proposed based on a combination of moso bamboo flour/silane KH550/high density polyethylene (HDPE), and the materials were characterized by diffractometry, spectroscopy, microscopy, and calorimetry. During surface modification, reactions between bamboo and silane occurred on the lignin aldehyde group. After 6 wt% KH550 treatment, crystallinity of bamboo was increased by 1.11 %, and melting temperature and enthalpy of the composite rose by 2.37 °C and 5.27 J/g, agreeing with improved interface morphology. Increasing in thickness from 3 to 9 mm, the physical and mechanical properties of composite were improved overall. Bamboo content caused the biggest influence, while thickness swelling exhibited the greatest susceptibility. Increasing the bamboo ratio boosted flexural and tensile properties, but it compromised toughness and water resistance, while silane and moulding parameters featured complicated relationships regarding performances. Combining an artificial neural network (ANN), KH550 3 wt%, moulding temperature of 180 °C, and a time of 8 min endowed 9 mm composites of 70 wt% bamboo with performance comparable to load bearing MDF in GB/T 11718. This research helped establish the first “Bamboo Plastic Composite” standard proposed by the authors for the Chinese forestry industry.

The purpose of this study was to investigate the effect of white mud (WM) on mechanical and thermal properties of bamboo plastic composites (BPCs). Bamboo residue fibers (BRFs) and WM were added as the reinforcement, and high-density polyethylene (HDPE) served as the matrix. The lubricating agent and coupling agent were polyethylene wax and maleated polyethylene (MAPE), respectively. The mixture was used to manufacture BPCs using a twin-screw extruder. The crystal structure and thermal properties of BPCs were investigated by X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results showed that the particle size of the WM was 700 nm to 50 μm, which are made mainly of calcium carbonate. BPCs with WM significantly increased the flexural and tensile properties, but the impact strength decreased because of the presence of WM. The flexural and tensile strength of composites with 18 wt% BPF were increased by 36.81% and 6.26%, respectively, while the flexural and tensile modulus were increased by 164.29% and 64.33%, respectively. XRD demonstrated the WM had little effect on the crystal structure of BPCs. Compared to BPCs without WM, the T5% of composites with 22 wt% WM decreased by 27.9 °C. As the WM content increased, the crystallinity of the BPCs decreased initially, then increased with increasing WM content.

This study inspected the thermal decomposition kinetics of core-shell structured wood-plastic composite material with white mud loading in the shell. The thermal decomposition was studied via thermogravimetric analysis under nitrogen atmosphere. Experiments were performed at different heating rates of 5, 10, 20, 30, and 40 °C/min from ambient temperature to 700 °C. Multivariate linear regression analysis was applied to estimate the activation energy with the Flynn–Wall–Ozawa method, and the thermal aging life equations of composites were obtained as described in ASTM E1877 (2000). The results showed that the combustion characteristic parameters (T5%, Tp1, Tp2, and Tp3) increased at first and then decreased with increased white mud concentration. Accordingly, the average apparent activation energy (Ea) values of thermal decomposition with conversion rates ranging between 20% and 80% were 222 kJ/mol for high-density polyethylene (HDPE) shell layer and the average values of 201, 226, 201, 207, and 223 kJ/mol were achieved with white mud loading of 5, 10, 15, 20, and 25% in the shell layer, respectively. There were no remarkable dependencies among them. The service life tf (min) and the service temperature T (K) of the core-shell structured wood-plastic composites were experimentally determined. [ABSTRACT FROM AUTHOR]

Bamboo can be processed into engineering materials with excellent properties by reasonable processing methods. In this study, the performance of mould-pressed bamboo (MBP) veneer products was examined. The physical mechanical properties and connection properties of MPB were tested, and the application performance of the MPB was analyzed. The results show that MPB has a comprehensive property of high internal bonding and good dimensional stability, and its density and mechanical properties are similar to those of wood dimensional stock. The overall bending strength, bending modulus, and compression strength of MPB were 29.0 MPa, 6.83 GPa, and 15.6 MPa, respectively. While the overall carrying capacity was relatively low, the connection performance of BPM was good. Thus, it can be used as a connector or substructure. [ABSTRACT FROM AUTHOR]

Self-bonding technology is potentially an effective solution to overcome formaldehyde emissions, which pose health and environmental concerns. Laccases can activate the fiber surface during the binderless fiberboard manufacturing process. This paper adopted wheat straw fibers (WSF) as the main raw material. The purpose of this study was to examine the effects of laccase pretreatment conditions on the mechanical properties of binderless fiberboards produced from WSF. For the improvement of mechanical properties, bamboo fibers (BF) were added as a reinforcing material. In addition, differences in the effects of two processes for adding laccase on the mechanical properties were monitored. As a result, binderless fiberboards were successfully manufactured from laccasetreated WSF. The results showed that the optimized pretreatment conditions were determined to be a laccase dosage of 40 U per gram absolute dry fiber (U/g), a treatment time of 120 min, a treatment temperature of 50 °C, and a proportion of BF of 20%. The mechanical properties of the binderless fiberboards prepared using a water bath were superior to spraying under the same conditions. [ABSTRACT FROM AUTHOR]