**2. Materials and methods**

Coir (fiber) which was extracted from coconut husk was cleaned with water to remove contaminants and dried at room temperature for 48 h. The dried fibers were soaked in 5 wt.% NaOH solution at room temperature (27 °C) for 30 min as a fiber treatment procedure. The treated coir was subsequently washed with distilled water to remove retained alkali. Furthermore, washed fibers of 30 mm length were open air dried for a day and afterwards dried at 60 °C in a hot air oven for 8 h. Further composite processing is reported elsewhere [30].
