Improvement of mechanical properties of Coir fiber (Cocus nucifera) with 2-hydroxyethyl methacrylate (HEMA) by photocuring

Coir fiber was cured under, ultraviolet radiation with 2-hydroxyethyl methacrylate (HEMA) in order to improve the mechanical properties with reduced water absorption character. A series of solutions of different HEMA concentrations in methanol, along with photoinitiator Irgacure 907, were prepared. The radiation dose, monomer (HEMA) concentration and soaking time were optimized with the extent of grafting of monomer and mechanical properties of cured fiber. five percent HEMA, 10-min soaking time. and a seventh pass of radiation produced the higher tensile strength (65%) and elongation at break (250%) than those of virgin fiber, as well as the highest grafting value (4.4%). For further improvement of the mechanical properties. the fibers were treated with alkali (Potassium Hydroxide) solution of various concentrations for one hour before curing. A 10% alkali-treated fiber showed the increased properties such as grafting (5.3%). tensile strength (9511), and elongation at break (320%) over raw fiber. The effect of additives (1%). such as acrylamid, urea, and silane [3-(triethoxy)propyl methacrylate] on the properties of coir fiber was) studied. Among the additives used. silane showed the best performance. The effect of simulating weathering on the degradable properties of samples was also performed. The silane-treated fiber produced the minimum loss of the properties, as well as a lower water uptake than those of the untreated one.