Moisture diffusion or uptake is one of the phenomenon observed in fibre reinforced composites exposed to marine ambience or water body structures. The materials are exposed to variations in temperatures and humidity. Moisture uptake depends upon the nature of the resin, porosity, temperature, humidity, salt water concentrations, fibre orientation, fibre volume fraction, void content, resin matrix interface, interfacial bonding. Moisture is known to react with one or more of the matrix constituents and hydrolyses the polymer bonds which leads to dissolution of water-soluble molecules and thereby plasticizing the matrix and lowering the glass transition temperature (Tg). Moisture absorption produces debonding of the fibre matrix interface and thus deteriorates the mechanical properties of the composites. It also causes swelling of the matrix phase and weakening/breaking of the matrix/fibre bond, formation of micro-cracks due to environmental stresses and polymer-solvent interactions. Hence the rate of deterioration is governed by the rate of moisture absorption and percentage of moisture content present. This affects the short-term and long-term durability of the composites. Hence determination of moisture content and rate of moisture diffusion is necessary to understand the kinetics of moisture diffusion. In this study three types of Fibre reinforced composites,glassfibre/polyester, glassfibre/vinylester and glassfibre/epoxy resin laminates are fabricated by Hand lay-up process and compacted in a Hotpress.An experiment is performed to compute the diffusion co-efficients at different times in hot-wet temperature of different fibre/resin combinations and theoretically evaluated by Fick’s law of diffusion.

"/> Diffusivity, Hand lay-up, Hotpress, Moisture diffusion,  resin.

"/> Moisture diffusion or uptake is one of the phenomenon observed in fibre reinforced composites exposed to marine ambience or water body structures. The materials are exposed to variations in temperatures and humidity. Moisture uptake depends upon the nature of the resin, porosity, temperature, humidity, salt water concentrations, fibre orientation, fibre volume fraction, void content, resin matrix interface, interfacial bonding. Moisture is known to react with one or more of the matrix constituents and hydrolyses the polymer bonds which leads to dissolution of water-soluble molecules and thereby plasticizing the matrix and lowering the glass transition temperature (Tg). Moisture absorption produces debonding of the fibre matrix interface and thus deteriorates the mechanical properties of the composites. It also causes swelling of the matrix phase and weakening/breaking of the matrix/fibre bond, formation of micro-cracks due to environmental stresses and polymer-solvent interactions. Hence the rate of deterioration is governed by the rate of moisture absorption and percentage of moisture content present. This affects the short-term and long-term durability of the composites. Hence determination of moisture content and rate of moisture diffusion is necessary to understand the kinetics of moisture diffusion. In this study three types of Fibre reinforced composites,glassfibre/polyester, glassfibre/vinylester and glassfibre/epoxy resin laminates are fabricated by Hand lay-up process and compacted in a Hotpress.An experiment is performed to compute the diffusion co-efficients at different times in hot-wet temperature of different fibre/resin combinations and theoretically evaluated by Fick’s law of diffusion.

"/> Moisture diffusion or uptake is one of the phenomenon observed in fibre reinforced composites exposed to marine ambience or water body structures. The materials are exposed to variations in temperatures and humidity. Moisture uptake depends upon the nature of the resin, porosity, temperature, humidity, salt water concentrations, fibre orientation, fibre volume fraction, void content, resin matrix interface, interfacial bonding. Moisture is known to react with one or more of the matrix constituents and hydrolyses the polymer bonds which leads to dissolution of water-soluble molecules and thereby plasticizing the matrix and lowering the glass transition temperature (Tg). Moisture absorption produces debonding of the fibre matrix interface and thus deteriorates the mechanical properties of the composites. It also causes swelling of the matrix phase and weakening/breaking of the matrix/fibre bond, formation of micro-cracks due to environmental stresses and polymer-solvent interactions. Hence the rate of deterioration is governed by the rate of moisture absorption and percentage of moisture content present. This affects the short-term and long-term durability of the composites. Hence determination of moisture content and rate of moisture diffusion is necessary to understand the kinetics of moisture diffusion. In this study three types of Fibre reinforced composites,glassfibre/polyester, glassfibre/vinylester and glassfibre/epoxy resin laminates are fabricated by Hand lay-up process and compacted in a Hotpress.An experiment is performed to compute the diffusion co-efficients at different times in hot-wet temperature of different fibre/resin combinations and theoretically evaluated by Fick’s law of diffusion.

"/> Moisture diffusion or uptake is one of the phenomenon observed in fibre reinforced composites exposed to marine ambience or water body structures. The materials are exposed to variations in temperatures and humidity. Moisture uptake depends upon the nature of the resin, porosity, temperature, humidity, salt water concentrations, fibre orientation, fibre volume fraction, void content, resin matrix interface, interfacial bonding. Moisture is known to react with one or more of the matrix constituents and hydrolyses the polymer bonds which leads to dissolution of water-soluble molecules and thereby plasticizing the matrix and lowering the glass transition temperature (Tg). Moisture absorption produces debonding of the fibre matrix interface and thus deteriorates the mechanical properties of the composites. It also causes swelling of the matrix phase and weakening/breaking of the matrix/fibre bond, formation of micro-cracks due to environmental stresses and polymer-solvent interactions. Hence the rate of deterioration is governed by the rate of moisture absorption and percentage of moisture content present. This affects the short-term and long-term durability of the composites. Hence determination of moisture content and rate of moisture diffusion is necessary to understand the kinetics of moisture diffusion. In this study three types of Fibre reinforced composites,glassfibre/polyester, glassfibre/vinylester and glassfibre/epoxy resin laminates are fabricated by Hand lay-up process and compacted in a Hotpress.An experiment is performed to compute the diffusion co-efficients at different times in hot-wet temperature of different fibre/resin combinations and theoretically evaluated by Fick’s law of diffusion.

"/>

Investigation of the Moisture Diffusion Process in Fibre- Reinforced Composites by Studying the Diffusivities in Hot-wet Temperature Resin-matrix

International Journal of Mechanical Engineering
© 2014 by SSRG - IJME Journal
Volume 1 Issue 2
Year of Publication : 2014
Authors : Sridhar Sathyanarayanan
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How to Cite?

Sridhar Sathyanarayanan, "Investigation of the Moisture Diffusion Process in Fibre- Reinforced Composites by Studying the Diffusivities in Hot-wet Temperature Resin-matrix," SSRG International Journal of Mechanical Engineering, vol. 1,  no. 2, pp. 7-12, 2014. Crossref, https://doi.org/10.14445/23488360/IJME-V1I2P102

Abstract:

Moisture diffusion or uptake is one of the phenomenon observed in fibre reinforced composites exposed to marine ambience or water body structures. The materials are exposed to variations in temperatures and humidity. Moisture uptake depends upon the nature of the resin, porosity, temperature, humidity, salt water concentrations, fibre orientation, fibre volume fraction, void content, resin matrix interface, interfacial bonding. Moisture is known to react with one or more of the matrix constituents and hydrolyses the polymer bonds which leads to dissolution of water-soluble molecules and thereby plasticizing the matrix and lowering the glass transition temperature (Tg). Moisture absorption produces debonding of the fibre matrix interface and thus deteriorates the mechanical properties of the composites. It also causes swelling of the matrix phase and weakening/breaking of the matrix/fibre bond, formation of micro-cracks due to environmental stresses and polymer-solvent interactions. Hence the rate of deterioration is governed by the rate of moisture absorption and percentage of moisture content present. This affects the short-term and long-term durability of the composites. Hence determination of moisture content and rate of moisture diffusion is necessary to understand the kinetics of moisture diffusion. In this study three types of Fibre reinforced composites,glassfibre/polyester, glassfibre/vinylester and glassfibre/epoxy resin laminates are fabricated by Hand lay-up process and compacted in a Hotpress.An experiment is performed to compute the diffusion co-efficients at different times in hot-wet temperature of different fibre/resin combinations and theoretically evaluated by Fick’s law of diffusion.

Keywords:

Diffusivity, Hand lay-up, Hotpress, Moisture diffusion,  resin.

References:

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