Alkali Concentration and Diluent Effects on Properties of Grape Cane Fiber-Reinforced Polymer Composites

The main objective of this study was to investigate the properties of polymer composites reinforced with grape cane fibers. The fibers were subjected to a sodium hydroxide (NaOH) treatment at two treatment concentrations to extract the fibers as well as fiber surface treatment. Panels were fabricated by hand lay-up and compression molding according to different fiber types, namely outer bark (OB) and whole (W) fibers. The whole fiber was a mixture of OB and inner bark (IB) fibers. Grape cane fibers were used as the reinforcement material for unsaturated polyester (UPE) resin panels. Acrylated epoxidized soybean oil (AESO) was used as a reactive diluent material with the UPE resin, and the results were compared with panels prepared with commercial styrene–UPE. There were inconsistent alkali treatment concentration effects on the mechanical properties and water absorption. However, panels fabricated with the whole bark fibers that have been treated with 1 wt % NaOH and had AESO–UPE resin resulted in the best tensile and flexural strength.

Polyetheretherketone Composites with Appreted Carbon Fibers

The paper investigates the processes of carbon fiber surface treatment and their influence on the properties of polyetheretherketone composites. It has been shown that preliminary thermal activation of carbon fiber followed by treatment with a dressing agent - polyhydroxyether makes it possible to create polyetheretherketone composite carbon-filled materials with an increased level of physical and mechanical properties.

Effect of Hemp Fiber Surface Treatment on the Moisture/Water Resistance and Reaction to Fire of Reinforced PLA Composites

The effects of surface pretreatment (water and alkali) and modification with silane on moisture sorption, water resistance, and reaction to fire of hemp fiber reinforced polylactic acid (PLA) composites at two fiber loading contents (30 and 50 wt.%) are investigated in this work. Moisture adsorption was evaluated at 30, 50, 75 and 95% relative humidity, and water resistance was determined after a 28-day immersion period. The cone calorimetry technique was used to investigate response to fire. The fiber surface treatment resulted in the removal of cell wall components, which increased fiber individualization and homogeneity as shown in scanning microscopic pictures of the composite cross-section. Although the improved fiber/matrix bonding increased the composite’s water resistance, the different fiber treatments generated equal moisture adsorption results for the 30 wt.% reinforced composites. Overall, increasing the fiber amount from 30 to 50 wt.% increased the composite sensitivity to moisture/water, mainly due to the availability of more hydroxyl groups and to the development of a higher pore volume, but fire protection improved due to a reduction in the rate of thermal degradation induced by the reduced PLA content. The new Oswin’s model predicted the composite adsorption isotherm well. The 30 wt.% alkali and silane treated hemp fiber composite had the lowest overall adsorption (9%) while the 50 wt.% variant produced the highest ignition temperature (181 ± 18 °C).

Effect of Wood Fiber Surface Treatment on the Properties of Recycled HDPE/Maple Fiber Composites

This work reports on the production and characterization of recycled high density polyethylene (R-HDPE) composites reinforced with maple fibers. The composites were produced by a simple dry-blending technique followed by compression molding. Furthermore, a fiber surface treatment was performed using a coupling agent (maleated polyethylene, MAPE) in solution. FTIR, TGA/DTG, and density analyses were performed to confirm any changes in the functional groups on the fiber surface, which was confirmed by SEM-EDS. As expected, the composites based on treated fiber (TC) showed improved properties compared to composites based on untreated fiber (UC). In particular, MAPE was shown to substantially improve the polymer–fiber interface quality, thus leading to better mechanical properties in terms of tensile modulus (23%), flexural modulus (54%), tensile strength (26%), and flexural strength (46%) as compared to the neat matrix. The impact resistance also increased by up to 87% for TC as compared to UC. In addition, the maximum fiber content to produce good parts increased from 15 to 75 wt% when treated fiber was used. These composites can be seen as sustainable materials and possible alternatives for the development of low-cost building/construction/furniture applications.

Weibull Strength Analysis of Pineapple Leaf Fiber

Pineapple leave fiber (PALF) can be considered as one of the green materials to the industries, which is the potential to replace the non-renewable synthetic fiber. However, the high disparity in the mechanical properties of PALF becomes an issue in structural composite design. Hence, improved Weibull distribution is utilised to quantify the tensile strength variation of PALF in various gauge lengths. The single fiber tensile test was performed after the fiber surface treatment and fiber diameter scanning. The predicted PALF strength by applying the improved Weibull distribution incorporating with conical frustum model is well compromised with experimental data compared to the traditional Weibull model.