3D Modelling of Mass Transfer into Bio-Composite

Abstract

A three-dimensional model structure that allows considering interphase layer around permeable inclusions is developed to predict water vapor permeability in composite materials made of a matrix Poly(3-HydroxyButyrate-co-3-HydroxyValerate) (PHBV) including Wheat Straw Fiber (WSF) particles. About 500 two-phase structures corresponding to composites of different particles volume fractions (5.14−11.4−19.52 % v/v) generated using experimental particles’ size distribution have permitted to capture all the variability of the experimental material. These structures have served as a basis to create three-phase structures including interphase zone of altered polymer property surrounding each particle. Finite Element Method (FEM) applied on these structures has permitted to calculate the relative permeability (ratio between composite and neat matrix permeability P/Pm). The numerical results of the two-phase model are consistent with the experimental data for volume fraction lower than 11.4 %v/v but the large upturn of the experimental relative permeability for highest volume fraction is not well represented by the two-phase model. Among hypothesis made to explain model’s deviation, the presence of an interphase with its own transfer properties is numerically tested: numerical exploration made with the three-phase model proves that an interphase of 5 µm thick, with diffusivity of Di≥1×10−10 m2·s−1, would explain the large upturn of permeability at high volume fraction.

Evaluation of the Behavior of Two CAD/CAM Fiber-Reinforced Composite Dental Materials by Immersion Tests

“…Most fiber-reinforced composite (FRC) dental materials contain three distinct constituent parts: (1) the continuous phase (which is also named matrix), (2) the dispersed phase (formed by the fibers, generally glass fibers), and (3) the interphase area [ 6 ]. The matrix, which is the majority, takes over the external stress forces on its surface and transforms them at the level of the dispersed phase, which often plays the role of reinforcement material, giving greater strength to the composite material [ 7 ].…”

Decontamination efficiency of poly(hydroxybutyrate‐co‐valerate)‐based food packaging material: The role of the chemical structure of contaminants and additive

“…Based on the kinetics of decontamination (Figure 2), it is clear that the decontamination of these molecules does not follow a Fickian diffusion behavior. 27 Thus, this process is not only a combination of diffusion/volatilization phenomena, but seems to be governed by the physicalchemical parameters of contaminants and their interactions with the polymer. The molecular weight of each contaminant as well as its polarity (expressed as Log K aw ) and vapor pressure are given in Table 1.…”

Biopackaging Potential Alternatives: Bioplastic Composites of Polyhydroxyalkanoates and Vegetal Fibers

“…Further modeling and experimental testing are essential to make better predictions. A 3D model of PHBV–wheat straw designed to predict water vapor permeability using the finite element method (FEM) to the 3D structures permitted a better prediction of water vapor permeability dynamics of the composite [ 129 ]. Numerical homogenization and representative volume elements (RVEs) are used to model composites’ effective elastic, thermal, and thermoelastic properties.…”