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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.Item Effect of stacking sequence on mechanical properties neem wood veneer plastic composites(2018) Nagamadhu, M.; Mohankumar, G.C.; Jeyaraj, P.This study investigates the effect of wood veneer stacking sequence on mechanical properties of neem wood polymer composite (WPC) experimentally. Wood laminated samples were fabricated by conventional hand layup technique in a mold and cured under pressure at room temperature and then post cured at elevated temperature. Initially, the tensile, flexural, and impact test were conducted to understand the effect of weight fraction of fiber on mechanical properties. The mechanical properties have increased with the weight fraction of fiber. Moreover the stacking sequence of neem wood plays an important role. As it has a significant impact on the mechanical properties. The results indicated that 0�/0� WPC shows highest mechanical properties as compared to other sequences (90�/90�, 0�/90�, 45�/90�, 45�/45�). The Fourier Transform Infrared Spectroscopy (FTIR) Analysis were carried out to identify chemical compounds both in raw neem wood and neem wood epoxy composite. The microstructure raw/neat neem wood and the interfacial bonding characteristics of neem wood composite investigated using Scanning electron microscopy images. � 2018 Author(s).Item Dynamic mechanical analysis of glutaraldehyde cross linked polyvinyl alcohol under tensile mode(2019) Mohankumar, G.C.; Jeyaraj, P.; Nagamadhu, M.Nowadays researchers are looking out for biodegradable materials alternate to petroleum-based materials due to many global issues. Polyvinyl Alcohol (PVA) cross-linked with Glutaraldehyde (GA) polymer have found widespread applications in light-weight structures in replacement of non-biodegradable polymers. The PVA cross-linked with GA polymers were prepared using a conventional compression type molding technique. Dynamic Mechanical Analysis has been carried out to evaluate the tensile storage and loss modulus, tan delta, and elongation, in the temperature range of 25-160�C. The results exhibit improvement of thermo-mechanical properties at higher temperatures due to GA crosslinking. Experimental results indicate that the tensile storage and loss modulus were improved due to GA crosslinking. The elongation of PVA-GA decrease considerably with GA crosslinking. The shore D hardness improves with crosslinking up to 20% GA, and further marginal increase in hardness beyond 20% GA crosslinking. � 2018 Author(s).Item A novel approach to determine the thermal transition of gum powder/hydro-gels using dynamic mechanical analysis(2018) Nagamadhu, M.; Jeyaraj, P.; Mohankumar, G.C.The dynamic characterization of materials plays a major role in the present area. The many researchers are worked on solid materials and its characterization, it can be tested using dynamic mechanical analyzer (DMA), however, no such work on powder a semiliquid samples. The powder and liquid samples can also easily characterization as like solid samples using DMA. These powder samples are analyzed with a material pocket method which can be used to accurately determine very low levels of variation in powder properties, due to the high sensitivity of DMA to glass transitions. No such DMA studies on hydrogel and Gum powders. The gum powders are used in various applications start from food industries, pharmacy, natural gums paste, biomedical applications etc. among all this applications gum Ghatti is one of the powders using for varies applications. Around 50 milligrams of Ghatti powders are placed inside material pocket and analyzed storage modulus (G?), loss modulus (G?) and tan delta (?). Also, understand the curing and glass transition effect using water, glycerin and superplastic from room temperature to 200�C. The result shows that storage modulus decreases with increase in temperature in pure Ghatti powder. The surprising improvement in storage modulus was found with an increase in temperature with addition of water, glycerin, and superplastic. However, loss modulus and tan delta are also having very significant influence and also shows a clear peak of the tan delta. The loss modulus results were found to be improved by adding solidifying agents, along with this water and superplastic better influence. But glycerine found to be hydrogel in nature and thermodynamic properties are much influenced by frequency. � 2018 Author(s).