Properties Enhancement of Mengkuang Leaf Fiber/Ethylene‐Vinyl Acetate/Natural Rubber Thermoplastic Elastomer Composites by Alkaline Peroxide Bleaching Treatment

Abstract

In this article, the effect of alkaline peroxide bleaching treatment using hydrogen peroxide on mengkuang leaf fiber (MLF) to the tensile, thermal properties and water absorption of thermoplastic elastomer composites based on ethylene-vinyl acetate/natural rubber and MLF was investigated. Fiber morphology and the fiber-matrix interface were further characterized by scanning electron microscopy (SEM). Treated composites showed better tensile properties than untreated fiber composites. SEM of the fractured surfaces of the composite specimens indicates that the bleaching treatment improved the interfacial interaction between the fiber and the matrix. The results of thermogravimetric analysis showed a higher thermal stability for treated composites than untreated composites. Furthermore, alkaline bleaching treatment has resulted in reduction of water absorption from 31% to 26% as compared with untreated composites. J. VINYL ADDIT. TECHNOL., 26:127-134, 2020. FIG. 6. Scanning electron micrographs of MLF subjected to different treatments. (a) untreated MLF (mag 500×), (b) untreated MLF (mag 700×), (c) treated MLF (mag 500×), and (d) treated MLF (mag 700×).

Valorization of coffee silverskin by cascade extraction of valuable biomolecules: preparation of eco‐friendly composites as the ultimate step

“…It can be deduced from the data derived from Horikawa's calibration that the residue CSS, subjected to extractions through pressurized fluid, contains the largest amount of lignin, whereas the lowest content is obtained for r‐CSS‐b. This datum is expected, because the bleaching process is a treatment that breaks the hydrogen bonds present on the surface of the residue, improving its roughness and crystallinity, and removes the lignin and hemicellulose 38,39 …”

“…This datum is expected, because the bleaching process is a treatment that breaks the hydrogen bonds present on the surface of the residue, improving its roughness and crystallinity, and removes the lignin and hemicellulose. 38,39 To investigate the biomass composition further, TGA measurements were also performed and the resulting curves are shown in Fig. 7.…”

“…Further treatments, such as the bleaching step, can further modify the surface of the residue by breaking the hydrogen bonds. This treatment improves the surface roughness, as well as increases the surface area, producing an increased phases interaction 38,39 …”

“…This treatment improves the surface roughness, as well as increases the surface area, producing an increased phases interaction. 38,39 Ultrasound-assisted extraction (UAE) is also considered to be a green technology suitable for overcoming several drawbacks associated with the conventional extraction of compounds, such as long extraction times and high temperatures, which could lead to denaturalization of the relevant compounds. The application of power ultrasound causes damage to the material (plant) cell walls due to the cavitation effect, 40 which eases the release of the bioactive compounds into a suitable solvent.…”

Microstructure-properties of dynamically vulcanized mengkuang leaf fibre/ethylene vinyl acetate/natural rubber thermoplastic elastomer composites

“…6. This was due to the poor interfacial adhesion that lowers the ability of Mengkuang leaf fibre to support stress transfer from the EVA/NR matrix phase (Hashim et al 2020). The effective stress transfer between the matrix and the fibre determines the tensile properties of the composites (Hayeemasae and Ismail 2021).…”