EFFECT OF ALKALINE TREATMENT ON MECHANICAL PROPERTIES OF ALFA FIBER/UNSATURATED POLYESTER COMPOSITE

Researchers are showing increasing interest in plant fiber reinforced composites due to their eco-friendliness, low density, low cost and amazing mechanical properties. However, some challenges remain for researchers in this field, most notably poor adhesion between the polymer matrix and the plant fibers, which reduces the mechanical properties of composites reinforced with these fibers. This study aims to improve the adhesion between the matrix and the reinforcement by chemically treating Alfa fibers (Stipa tenacissima) with a 3 wt% NaOH solution at different times (1, 3, 5 and 24 h). FTIR, DRX, GTA and tensile tests were conducted. XRD tests showed that the crystallinity index of 3% alkali treated Alfa fibers for 5 h increased by 36.26%, compared to that of untreated fibers. The results also revealed that the mechanical properties of composites reinforced with treated fibers outperformed those reinforced with untreated fibers. These findings can contribute to the development of high mechanical performance composites, which can be competitive with those prepared with synthetic fibers.