1. Journal Articles
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Item No Access Influence of glutaraldehyde on dynamic properties of poly(vinyl alcohol) polymer(ICE Publishing, 2020) Mohan Kumar G.C.; Pitchaimani, 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.Item Mechanical Properties of Chemical Treated Woven Banana/Polyvinyl Alcohol Composites(2019) Gunge, A.; Kivade, S.B.; Nagamadhu, M.; Gunge, A.Present work investigates the effect of chemical treatment on mechanical properties of plain woven banana fabrics (PWBF) reinforced to polyvinyl alcohol (PVA) bio-degradable matrix composite. Woven banana fabrics are chemically treated with different percentages of concentration (0.5, 1, 2, 3 and 4%) for 4 hours at room temperature. The banana fabrics and PVA are used in the ratio of 55% and 45% weight fraction respectively. Composites are prepared using hand-layup method. The samples are tested according to different ASTM standard for tensile, flexural and impact.The results are exhibited that tensile, flexural and impact properties were found to increase with potassium permanganate (KMnO4) treatment. The 1% potassium permanganate treated fabrics shows very good mechanical properties compared to untreated, 0.5, 2, 3 and 4% treated fabrics, 1% treated fabrics gives 68.07% increment in the tensile strength of the composite compared to the untreated fabrics composite. The scanning electron microscopy (SEM) also reveals 1% treated has the better interfacial bonding between fabrics and matrix. This contributes to improvement in the mechanical properties of the composite. 2019 ICE Publishing: All rights reserved.Item Mechanical and tribological behavior of woven sisal fabric(2019) Nagamadhu, M.; Jeyaraj, P.; Mohankumar, G.C.A study has been carried out to investigate the Mechanical and Tribological Properties of Woven Sisal Fabric. Two Plain fabrics were prepared by changing gram per unit area (GSM), and one weft rib fabric is prepared to understand the effect of woven structure on mechanical and wear properties. These fabrics textile properties were determined as per textile ASTM standards. The tensile properties of these fabrics were studied in both warp and weft directions. Further, pilling resistance, abrasion resistance and wear properties of these fabrics were studied using L27 Taguchi Orthogonal Array. The tensile properties were found to be better in weft direction as compared to warp direction in all type of fabrics. The pilling resistances were found better in weft rib fabrics. The abrasion resistance is exhibited better at higher GSM. From the results, it also reveals that higher the crimp value more the resistance against adhesion wear using Pin on disk method. More the yarn linear density more the resistance for adhesion wear. However, the wear load, woven pattern and traveling distance have a significant impact on weight loss and frictional force. 2019 Published by Faculty of Engineering.Item Influence of textile properties on dynamic mechanical behavior of epoxy composite reinforced with woven sisal fabrics(2020) Nagamadhu, M.; Jeyaraj, P.; Mohankumar, G.C.Due to low cost and environmentally friendly characteristics, natural fibers gain much attention over synthetic fiber. The aim of the present work is to characterize the textile properties of three different types of sisal fabric and study dynamic mechanical properties and water absorption behavior of the sisal fabric reinforced epoxy composite. Influence of grams per square meter of fabric, weaving pattern of the fabric on textile properties of the fabric is studied first. Further, the effect of the same on the dynamic mechanical properties of the sisal composites is studied. Effect of fiber weight percentage and dynamic frequency on dynamic mechanical properties also studied. Results reveal that the storage modulus (G?) decreases with increasing temperature in all the woven types of composites under consideration. However, Plain 2 (P2) and Weft Rib (WR) composites have shown better values of G? even after the glass transition temperature (Tg). From the results, it is also evident that storage and loss modulus (G??) increases when the yarn diameter decreases which is observed at a higher temperature also. It is also observed that fabric density also plays a significant role in the enhancement of G? and G?? values. The water absorption of Plain 1 (P1) based composites are found to be less compared to the other types of composites analyzed. 2020, Indian Academy of Sciences.Item Characterization and mechanical properties of sisal fabric reinforced polyvinyl alcohol green composites: Effect of composition and loading direction(2019) Nagamadhu, M.; Jeyaraj, P.; Mohankumar, G.C.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.