Effect of alkali treatment on the flexural properties of Hildegardia fabric composites

Abstract

ABSTRACT:A uniaxial natural fabric of Hildegardia populifolia was treated with 5% sodium hydroxide solution for 1 h, and the resulting changes were analyzed by polarized and scanning electron microscopic techniques. The untreated and treated H. populifolia fabric was reinforced in epoxy and toughened with 10% polycarbonate. The variation of the flexural strength and flexural modulus with different fabric contents and fiber orienrations was studied. The effect of sodium hydroxide and a silane coupling agent on the flexural properties of the composite was also studied.It was observed that the flexural properties increased on alkali treatment and when the coupling agent was used. The morphology of the cryogenically fractured surfaces indicated good bonding between the matrix and the reinforcement when a coupling agent was used.

Chemical resistance, void contents, and morphological properties of Hildegardia fabric/polycarbonate‐toughened epoxy composites

“…The different angles of orientation were achieved by samples being cut at different angles from the molded composite. We took a piece of Hildegardia fabric that was approximately 150 3 100 mm 2 and inserted it layer by layer into the mold; at the same time, the matrix material was also added until the mold was filled with the fabric and matrix. We then covered the mold with a Teflon sheet and kept it in a vacuum oven overnight to remove the bubbles.…”

“…The density of the fabric also increased with an alkali treatment. 2 The surface of the fibers in the fabric became rough with the removal of hemicellulose and lignin. All these factors contributed to the improvement of the bonding between the reinforcement and the matrix.…”

Impact Strength, Water Absorption and Chemical Resistance of Untreated and Treated Cordia-Dichotoma Fiber/Polyester Composite

“…After this treatment, fiber surface becomes rough and this can further improve fiber-matrix adhesion by providing additional fiber sites for mechanical interlocking. Mechanical behavior of the composite is enhanced significantly by this treatment [7]. The mechanical testing of most of the composite materials is mainly concerned with high elastic modulus, stiffness and strength.…”

Bio-film Composites Composed of Soy Protein Isolate and Silk Fiber: Effect of Concentration of Silk Fiber on Mechanical and Thermal Properties

“…But unfortunately, the natural matrices are brittle with low mechanical properties and are not suitable for packaging materials in their original form. In order to improve the mechanical properties, they are often reinforced with natural fibers/fabrics such as hemp [12][13][14], sisal, Alfa [15], kenaf [16], Hildegardia [17,18] etc. Due to their abundance and economics, protein matrices are preferred.…”