Faculty Publications
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Item Characterization and mechanical properties of sisal fabric reinforced polyvinyl alcohol green composites: Effect of composition and loading direction(Institute of Physics Publishing helen.craven@iop.org, 2019) Nagamadhu, M.; Jeyaraj, P.; Mohan Kumar, G.C.M.This research focuses on microstructure characterization and exploring mechanical properties of sisal fabric reinforced Polyvinyl Alcohol composites using conventional vacuum-assisted pressure compression method. Naturally available sisal fiber is used as reinforcement material in this composite because of its abundant availability in Southern India. The sisal fiber, PVA and its composites were characterized using Fourier Transform Infrared Spectroscopy. Initially, Polyvinyl Alcohol polymer was cross-linked with Glutaraldehyde, and mechanical properties were evaluated. It was observed that 20% Glutaraldehyde and 80% Polyvinyl Alcohol polymer combination yielded best mechanical properties. Further, two plain and one weft rib were considered and their textile properties were characterized. The results revealed that fabric crimp and yarn linear density had significant influence on tensile properties of the fabric. Influence of different fabric properties such as weaving pattern, grams per unit area, and loading direction on mechanical properties of composites were analyzed. The woven fabric having least gram per unit area of sisal resulted in best mechanical properties like tensile, bending, and impact. The weft rib fabric composites in weft direction exhibited best mechanical properties. © 2019 IOP Publishing Ltd.Item Influence of glutaraldehyde on dynamic properties of poly(vinyl alcohol) polymer(ICE Publishing, 2020) Mohan Kumar, G.C.M.; Jeyaraj, J.; Nagamadhu, M.This study investigated the dynamic mechanical properties of poly(vinyl alcohol) (PVA; (CH2CH(OH)) n ) cross-linked with glutaraldehyde (GA; OHC(CH2)3CHO).*The cross-linked polymer was prepared by using a conventional casting technique and then treated with sulfuric acid (H2SO4) for 24 h.*The flexural properties during static and dynamic modes were studied using a three-point bending condition.*The static flexural properties are improved with the addition of 30% GA in PVA, with higher value of strain.*It was observed that the dynamic mechanical properties of PVA improved significantly with an increase in cross-linking percentage.*The storage and loss moduli increased drastically with the addition of the cross-linker up to 20%, and marginal changes occurred with further addition of the cross-linker.*The fracture behavior was transformed from ductile to brittle for more than 20% cross-linker.*Shifting of the rubber region and liquid region with higher temperatures was observed in storage and loss modulus plots.*Improvement in the adhesion factor, cross-linking density and effectiveness was observed for GA up to 25%.*The test duration was estimated using the Williams-Landel-Ferry model for different temperatures.*The major changes were in the modulus in the rubbery plateau region.*The cross-linked polymer had much greater storage and loss moduli, indicating a closer network structure and higher stiffness.* © 2020 ICE Publishing: All rights reserved.