Effect of Graphite Oxide Dispersion Evaluated with Multifractal on Mechanical Properties and Thermal Stability of Poly(3hydroxybutyrate‐<i>co</i>‐4hydroxybutyrate)/Graphite Oxide Biocomposites

Filler dispersion is one of the key factors that significantly affect the performance of composite materials. Quantitative description of the dispersion state of fillers in composites and the internal relationship between the dispersion state and the macro‐mechanical properties of composites are very important for the performance design, prediction and processing process control of composites. In order to quantitatively and visually describe the dispersion state of inorganic fillers in matrix, research the relationship between fillers dispersion and composites properties. Here, by the fluorescent labeling technology of inorganic fillers and the surface organic modification technology, a modified fluorescently labeled calcium carbonate (MF‐CaCO3) with red fluorescence effect and good dispersibility was obtained, and polypropylene (PP)/MF‐CaCO3 composites with different loadings were prepared (the weight concentrations of MF‐CaCO3 in filler is 2, 5, 10, 15, and 20 wt%, respectively). The fractal dimension D value for evaluating the uniformity of filler dispersion has been successfully received, based on fractal analysis and fluorescent labeling‐laser scanning confocal microscope three‐dimensional (3D) visualization technology. Through the statistical results of experimental data, it was found that the value of fractal dimension D was obviously negatively correlated with the macroscopic mechanical properties of composite materials. When the dispersion of the filler was the best, that is, the fractal dimension D value took on a minimum and the composites had the best impact resistance. At the same time, this method based on fractal analysis and 3D visualization technology provides a new idea for quantitatively describing the dispersion state of fillers and its relationship with the mechanical properties of composites.

Section: Introductionmentioning

confidence: 99%

Quantitative description of filler dispersion in composite materials by fractal analysis and fluorescent labeling‐LSCM visualization technology

Wei

Zhao

et al. 2022

“…The fractal theory was originally proposed by Mandelbrot based on statistical theory that provides a scientific way to characterize the dispersion state of fillers . Some fractal researches on the dispersion structure of inorganic fillers in composites based on cross‐sectional SEM images have been carried out . However, given a large number of fillers that may exist in the image, using manual counting techniques, the statistics can take a lot of effort and time.…”

Section: Introductionmentioning

confidence: 99%

Quantitative evaluation of fillers dispersion state in CaCO₃/polypropylene composites through visualization and fractal analysis

Kang

Yuan

et al. 2019

The dispersion state of fillers in the polymer matrix is an important factor to determine the properties of the polymer composites. Here, a new method for the accurate quantitative evaluation dispersion state of fillers through three‐dimensional (3D) visualization and fractal analysis is reported. First of all, the data model of the dispersed state of the fillers is obtained through 3D visualization techniques. Then the fractal dimensions of different samples are obtained by software based on the fractal theory. As the filler increases, the fractal dimension is firstly decreases to a minimum and then increases. Under this extreme point condition, the theoretical dispersion state of the fillers is uniform. The accurate quantitative description of the dispersion state provides a new basis for establishing the relationship between the dispersion state and the mechanical properties of the fillers in various composites.

Preparation and performance optimization in high‐voltage cable semiconductive shielding layer for polyolefin composite based on multifractal analysis

Zhang,

Liu

et al. 2023

In this study, the semiconductive shielding composite was prepared successfully using the melt mixing method. The effects of combining multiwall carbon nanotubes (MWCNT) and carbon black (CB) into polyolefin plasticizers/ethylene vinyl acetate/linear low density polyethylene matrix on the mechanical performances, electrical conductivity, and processing rheological properties of the samples were investigated. The research results indicate that adding MWCNT to the prepared semiconductive shielding composite can form a complete conductive network, and its synergistic effect with CB jointly improves the conductivity of the composite material. Compared with the absence of MWCNT, its bulk resistivity decreased from 1.61 W • cm to 0.89 W • cm, a decrease of 44.7%. At the same time, the prepared semiconductive shielding composite has excellent mechanical and processing performances. The elongation at break, maximum tensile strength, and elastic modulus of the composites were increased by 30.9%, 17.9%, and 4.9%, respectively. Based on multifractal analysis, by adjusting the content of MWCNT in composite and optimized processing paths, the distribution and microstructure of MWCNT in composite can be optimized to obtain adjustable mechanical and processing rheological properties. This study presents a guiding approach for designing and developing functional composites requiring adjustable mechanical performances.Highlights The semiconductive shielding composite was prepared successfully. The prepared composite has excellent mechanical and processing performances. Multiwall carbon nanotubes with carbon black can form conductive network. The microstructure can be optimized by quantitative characterization of the morphology.