Cuicui Wang

Interfacial Properties of Bamboo Fiber-Reinforced High-Density Polyethylene Composites by Different Methods for Adding Nano Calcium Carbonate

The focus of this study was to observe the effect of nano calcium carbonate (CaCO3) modification methods on bamboo fiber (BF) used in BF-reinforced high-density polyethylene (HDPE) composites manufactured by extrusion molding. Two methods were used to introduce the nano CaCO3 into the BF for modification; the first was blending modification (BM) and the second was impregnation modification (IM). In order to determine the effects of the modification methods, the water absorption, surface free energy and interfacial properties of the unmodified composites were compared to those of the composites made from the two modification methods. The results revealed that the percentage increase in the weight of the composite treated by nano CaCO3 decreased and that of the IMBF/HDPE composite was the lowest over the seven months of time. The results obtained by the acid-base model according to the Lewis and Owens-Wendt- Rabel-Kaelble (OWRK) equations indicated that the surface energy of the composites was between 40 and 50 mJ/m2. When compared to the control sample, the maximum storage modulus (E′max) of the BMBF/HDPE and IMBF/HDPE composites increased 1.43- and 1.53-fold, respectively. The values of the phase-to-phase interaction parameter B and the k value of the modified composites were higher than those of the unmodified composites, while the apparent activation energy Ea and interface parameter A were lower in the modified composites. It can be concluded that nano CaCO3 had an effect on the interfacial properties of BF-reinforced HDPE composites, and the interface bonding between IMBF and HDPE was greatest among the composites.

Dipping Modification with Nano-CaCO3 to Improve Tensile Properties of Individual Bamboo Fiber for Developing Bamboo–Plastic Composite

ABSTRACT Nano-CaCO3 dipping modification was proposed to improve the tensile performance of individual bamboo fiber prepared by sulfate process. Effects of nano-CaCO3, EDTA-2Na concentration, and dipping time on the morphological and mechanical of fiber were characterized. Results show that sulfate isolated fiber surface is smooth and porous, providing potential adsorption site for nano-particle. Under nano-CaCO3 1.00 × 10–2 g/mL, EDTA-2Na 6.25 × 10–4 g/mL, and a dipping time of 25 min, both the number and the size distribution of nano-CaCO3 are relatively uniform while tensile parameters achieve maximums (i.e., tensile strength 1302.47 MPa, modulus of elasticity 61.83 GPa, and elongation at break 3.38%).

Characterization and Research on Mechanical Properties of Bamboo Plastic Composites

The focus of this study was to observe the mechanical properties of bamboo plastic composites (BPCs) with bamboo pulp fiber (BPF) or white mud (WM). The essential work of fracture (EWF) methodology was used to characterize the impact toughness of BPCs. The results revealed an increase in flexural, tensile and impact properties, when adding the BPF in the BPCs. While the flexural properties of WM-reinforced BPCs revealed increasing, there was a decrease in tensile and impact strength. In an impact strength analysis study, BPF-filled BPCs showed excellent impact property over WM-filled BPCs; scanning electron microscopy (SEM) helps to explain impact fracture behavior of BPCs. EWF analysis of impact results showed that the specific essential work of fracture (we) increased significantly with the amount of BPF used in BPCs but decreased with the increase of WM in the BPCs. There was similar variation for the non-essential plastic work (βwp) of BPCs. This result indicates that the fracture initiation and fracture propagation of BPCs are different.

Fractal dimension analysis of interface and impact strength in core–shell structural bamboo plastic composites

To analyze quantitatively the interface of core–shell structural bamboo plastic composites (BPCs) surface, the relationship between the microstructure of composite surface and the macroscopic impact performance was investigated. The effect of shell layer on the interface and impact strength of the core–shell BPCs was studied by scanning electron microscope (SEM) images, computer image processing technique and fractal theory. The fractal dimensions of the core–shell BPCs were calculated and the relationship between the measured impact strength and the fractal dimensions of the core–shell BPCs fracture surface was discussed. The results showed that the fractal dimensions of the interface and fracture surface were within the range of about 2.1725 to 2.1970 and 2.2075 to 2.2204, respectively. All the correlative coefficients were higher than 0.99, therefore, the strong linear correlation indicated that the fractal characterization of the interface and impact fracture surface for the BPCs was possible, and also proved that the interface could be analyzed quantitatively depending on the feature parameters of the fractal dimension. The relationship between the fractal dimension and the measured impact strength was linear. The bigger the fractal dimension of surface, the bigger the impact strength and stronger the interfacial bond were. Thus, using the fractal dimensions the surface morphology of core–shell structural BPCs can be described and it may provide a new approach to investigate the inherent rules of fractal characteristics and Charpy impact strength of the BPCs with core–shell structure.