Effects of high‐temperature optimization and resin coating treatment on the mechanical, thermal, and morphological properties of natural kenaf fiber‐filled engineering plastic composites

Abstract

In this study, kenaf natural fibers were coated with acetone‐thinned epoxy resin before compounding with high‐temperature polyethylene terephthalate (PET). Thus, composites of sodium hydroxide treated and epoxy‐resin coated kenaf fibers (KF) reinforced PET (CTKF‐PET) were manufactured using extrusion and compression molding techniques at an optimized 10 wt% constant fiber loading and processing temperatures of 240, 250, and 260°C, and were characterized for mechanical, thermal, and morphological performances. The obtained results showed an optimum processing temperature of 240°C with maximum mechanical and thermal properties with good interfaces between the coated fillers and the matrix, compared to those obtained at 250 and 260°C. Thermogravimetric analysis recorded maximum onset degradation and decomposition temperatures of 338.9 and 381°C with 9.5% and 13% improvements respectively after resin coating which positively impacted the constituent coated composites compared to the uncoated KF. Differential scanning calorimetry glass transition (Tg) and melting temperatures (Tm) for the CKF‐PET composites was maximum at 119.0 and 262.8°C with 2.18% and 2.8% improvements respectively compared to uncoated composites. The overall properties of all coated kenaf‐reinforced PET (CKF‐PET) and coated‐treated (CTKF‐PET) composites were higher with improved morphological properties irrespective of the processing temperature compared to the raw kenaf (KF‐PET) composites. Hence, natural fibers can be treated with resin coating to improve the thermal stabilities of natural fiber engineering plastic composites, and the interfacial adhesion between the coated‐KF and the engineering plastic matrix. The resultant composites are suitable for high‐temperature engineering applications such as the automotive and construction industries.

Mechanical and thermal properties of recycled polyethylene/surface treated hemp fiber bio‐composites

“…FTIR spectroscopy was used to detect changes in the chemical structure of raw hemp during the extraction process (Figure 3). In the untreated and extracted fibrils, a wide absorption band between 3300 and 3500 cm −1 corresponding to stretching vibrations of the free OH groups in cellulose were recorded 52–54 . The increase in the intensity of this band indicates an increase in cellulose content due to the removal of the lignin after chemical treatments 55 .…”

“…In the untreated and extracted fibrils, a wide absorption band between 3300 and 3500 cm À1 corresponding to stretching vibrations of the free OH groups in cellulose were recorded. [52][53][54] The increase in the intensity of this band indicates an increase in cellulose content due to the removal of the lignin after chemical treatments. 55 The bands at about 2900 cm À1 belong to stretching vibration of methyl and methylene groups.…”

Enhanced ablation resistance of carbon/phenolic composites based on mesophase pitch reinforced particles

“…To facilitate the examination of MP's polarized microscopy morphology, a pre-embedding process involving epoxy resin was employed for the solid block of MP. 28,29 This was followed by a series of sequential grinding and metallographic polishing treatments. Due to the inherent optical anisotropy of MP, it exhibited distinctive alternating bright and dark extinction fringes when observed under a polarized microscope using reflected orthogonal polarized light.…”

Investigation of the flame properties and fire behavior of carbon‐reinforced PEKK, BMI and phenolic composites impacted by Jet‐A1/air flames

“…Therefore, the values could be higher in smaller compartments and thereby posing a very serious human and environmental risk. [43][44][45] Figures 12 and 13 reveal the images of the composite materials before and after the fire resistance test, respectively. A more compact structure after the test would suggest that the material retained its original shape and form and did not suffer significant damage or deformation.…”