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Your search keyword '"Stephen, Ranimol"' showing total 13 results
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13 results on '"Stephen, Ranimol"'

10. Thermal properties of poly (vinyl alcohol)(PVA)/halloysite nanotubes reinforced nanocomposites

Author

V.P., Swapna, P., Selvin, K.I., Suresh, V., Saranya, M.P., Rahana, and Stephen, Ranimol

Abstract

Natural halloysite nano clay with tubular structure was used for the preparation of polyvinyl alcohol (PVA) nanocomposites. A systematic and detailed study was conducted on the effect of nanotubes on the properties such as flame retardancy, water absorption capacity, and thermal stability of poly (vinyl alcohol) matrix. Morphological and structural characterizations of nanocomposites were performed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and fourier transform infra red (FTIR) spectroscopy. XRD results showed peak broadening and disappearance in nanocomposites when compared to the peaks for nanotubes, indicating the better dispersion of nanotubes in the matrix. Owing to the hydrophilicity of nanotubes the nanocomposites exhibited enhanced water sorption properties. At higher temperature nano filler reinforced PVA showed better thermal stability and flammability due to barrier effect.

Published
2024
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11. Kinetic studies on the transport behavior of hybrid filler incorporated natural rubber (NR).

Author

Abhisha, Vakkoottil Sivadasan, Sisanth, Krishanagegham Sidharathan, Thomas, Sabu, and Stephen, Ranimol

Subjects
CARBON-black, CARBON nanotubes, DIFFUSION control, RUBBER, VULCANIZATION
Abstract

Conductive carbon black (CCB), carbon nanotubes (CNT) and its hybrids are introduced into the natural rubber (NR) matrix aiming to explore the effect of filler ratio on the transport properties. Solvent transport of NR is found to decrease for hybrid filler systems as compared to single filler incorporated systems. Kinetic parameters of solvent transport behavior of filled NR systems are analyzed using various kinetic models. Upon the computation of kinetic parameters of transport data, it is found that the Peppas-Sahlin model is in good agreement with experimental observations, which suggests that the transport mechanism is diffusion controlled. Rubber-filler interaction parameters are computed and analyzed from the swelling experiments using Kraus, Cunneen-Russel, and Lorenz-Park equations. [ABSTRACT FROM AUTHOR]

Published
2023
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13. Efficient cage structured polyhedral oligomeric silsesquioxane embedded poly(vinyl alcohol) membranes: Thermal degradation and mechanical stability in hydrated condition.

Author

Swapna, Valiya Parambath, Krishnan, Meera, Abhisha, Vakkoottil Sivadasan, and Stephen, Ranimol

Subjects
POLYMER networks, ETHYLENE oxide, POLYMER structure, ALCOHOL, THERMAL stability, SILICONES, POLYVINYL alcohol
Abstract

In this work, the thermal degradation of functionalized cage structured polyhedral oligomeric silsesquioxane (POSS) incorporated poly(vinyl alcohol) (PVA) and poly(vinyl alcohol)‐poly (ethylene oxide) (PEO) blend membranes were discussed. PVA‐PEO/POSS and cross‐linked PVA/POSS systems exhibited excellent improvement in thermal stability at lower loading of POSS as compared to pure PVA and uncross‐linked PVA/POSS system. Uncross‐linked PVA and PVA/POSS systems exhibited mainly two degradation steps. However, cross‐linked PVA/POSS systems showed more degradation steps due to the formation of 3‐dimentional network structure in the polymer. The mechanical stability of PVA/POSS and PVA‐PEO/POSS systems at hydrated state were analyzed and observed a remarkable stability even in the wet condition. [ABSTRACT FROM AUTHOR]

Published
2021
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