Role of Urea on the Physico-Mechanical and Degradable Properties of Mercerized and Acid Hydrolyzed Coir (Cocos nucifera) Fibers Photocured with 1,6-Hexanediol Diacylate

Abstract

Coir fibers were modified with 1,6-hexanediol diacrylate (HDDA) by using ultraviolet (UV) radiation. Concentration of HDDA, soaking time, and radiation dose were optimized and found to be 30% HDDA in methanol along with photoinitiator Irgacure-500 (2%) and 120 min of soaking time the better performance registered as the optimum conditions, where polymer loading (PL) was 17% and tensile strength (TS) was 50%. Urea of different concentrations (0.5-2%) was incorporated with 30% HDDA to monitor its effect on the properties and 1% urea produced the enhanced PL (25%) and TS (82%). For the improvement of the properties, the fibers were subjected to surface treatment with alkali (5% potassium hydroxide) at various mercerizing times in hot and normal conditions. Among all the mercerized fibers, fibers treated with hot alkali for 6 h and cured under optimized condition demonstrated the maximum enhancement of PL (35.5%) and TS (130%). The fibers were also subjected to acid hydrolysis for different times with different acid (H 2 SO 4 ) concentrations. Again the effect of urea (1%) on the properties of the pretreated fibers was scrutinized. Water uptake and degradable properties of the treated and virgin fibers were performed.

Effect of Surface Modification of Jute with Acrylic Monomers on the Performance of Polypropylene Composites

“…This means TS and TM increase with the decrease of monomer concentration and the increase of the content of solvent in the formulations. This could be regarded as a fact that in dilute formulations, the solvent can easily penetrate into the core of fibers, as a result, monomers can easily find out the sites on fiber for cross-linking or grafting, which consequently enhances the strength of composites [15]. Considering the formulations between F4 and F5, it was reported that the F5 treated jute fabrics showed higher mechanical properties because of the reduction of oligomer from 5 to 2.5%.…”

“…When the monomer concentration is increased, the amount of residual concentration is also increased and causes the faster rate of formation of threedimensional network structures causing restricted mobility. At higher monomer concentration, radical-radical recombination process may be dominating and the formation of homo-polymer rather than monomer-cellulose reaction may be prominent [15] resulting in the decrease in mechanical strength as compared to that at low monomer concentration. Both the TS and TM increase up to a certain value with the increase of radiation dose and then decrease.…”

Effect of pretreatment with detergent on mechanical properties of photocured coir (Cocos nucifera) fiber with ethyleneglycol dimethacrylate

“…9,10 It was reported in the previous study that treatment of natural fibers with various monomers of different functionalities under UV irradiation improves their physical properties. [11][12][13][14][15] Ethylene glycol dimethacrylate (EGDMA) is one of the difunctional monomers that could be cured under UV radiation.…”

Fabrication and Characterization of Jute Reinforced Polypropylene Composite: Effectiveness of Coupling Agents

“…So, TS and TM of the composites increase with the increase of monomer concentration in the formulation solution with simultaneous decrease of solvent. In dilute formulations, solvent can easily penetrate into the core of fibers, as a result, monomers can easily penetrate in the fiber bundles thus enhancing cross-linking or grafting the monomer with jute during UV curing, which attributed higher mechanical properties of the composites [41]. Formulation F3 showed the higher mechanical properties.…”