EFFECT OF ALKALI AND SILANE TREATMENT ON WATER ABSORPTION AND MECHANICAL PROPERTIES OF SISAL FIBER REINFORCED POLYESTER COMPOSITES

Abstract

The present study investigates the effect of water absorption on the mechanical properties of untreated, 10% alkali-treated, and 10% alkali plus 1% silane treated sisal fibers (5%, 10%, and 15%) reinforced polyester composites. Hand lay-up was used to create the composite. The samples were prepared in accordance with ASTM standards, and tests for tensile strength, flexural strength, impact strength, and water absorption were performed. Without water absorption, an increase in fiber loading increased tensile, flexural, and impact strength for untreated, alkali-treated, and alkali plus silane treated sisal fiber reinforced polyester composites, with the increase being greatest for 10% alkali plus 1% silane treated fiber composite. Water absorption reduces tensile strength while increasing flexural and impact strength in untreated sisal fiber reinforced composites. There is an increase in tensile, flexural, and impact strength with higher fiber loading for 10% alkali-treated and 10% alkali-treated plus 1% silane treated sisal fiber reinforced polyester composites with and without water absorption. The tensile, flexural, and impact strength of alkali plus silane treated fiber is maximum at any given fiber loading, indicating that the alkali plus silane treatment is effective in improving the fiber matrix interface. Water absorption increases with fiber loading in untreated, 10% alkali-treated, and 10% alkali plus 1% silane treated sisal fiber reinforced polyester composites, with the rate being lowest in alkali plus silane treated fiber reinforced composites.