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Vacuum Infusion Molding of Natural Fibre Reinforced Biobased Resin Composite

Posted on:2017-03-25Degree:Ph.DType:Dissertation
University:University of Toronto (Canada)Candidate:Subbiah, RajkumarFull Text:PDF
GTID:1441390005460576Subject:Mechanical engineering
Abstract/Summary:
The increasing demand in the field of bio material research for an in-depth understanding of processing phenomenon to convert it into a useful product is essential. Besides, there is inadequate information regarding the dependency between their processing mechanism and mechanical performance. The main focus of this work is to address the issues of the resin flow behavior of natural fibre in vacuum infusion molding, the determination of permeability and validation of the proposed contact angle model with experimental data. The proposed model shows greater accuracy when validated with experimental observation. The outcome of this research emphasizes the wetting mechanism and fibre network of sisal mats are the major factors that reduces 26% of permeability as compared to glass fibres. In addition, it is observed that the swelling phenomenon had a minimal influence on the permeability of the sisal fibre mat.;The complex phenomena occurring during wetting of natural fibres with epoxidized soybean oil (ESO) in terms of contact angle and surface energy are investigated. The fibres are treated with various reagents to improve the wetting behavior. It is noted that NaOH treatment provides considerable amount of increase in surface area of the exposed cellulose that aids in enhancement of wettability characteristics by increasing the surface energy from 18 mN/m to 23.5 mN/m while reducing the contact angle from 530 to 310. Conversely, there is a formation of virtual layer on the fibre when treated with silane and isocyanate. Moreover, isocyanate treated fibre exhibits improved wetting behaviour in terms of increase in surface energy from 18 mN/m to 25.5 mN/m when wetted with ESO.;The kinetics study of the curing reaction of the resin is performed by differential scanning calorimetry. A new empirical model is proposed to analyze the kinetic data obtained experimentally. The results highlighted that the proposed model attained significant improvement to predict the experimental cure kinetic data qualitatively and quantitatively. The addition of 30% ESO in the conventional system increases the activation energy of the system up to 108 kJ/mol. The effect of the surface treatments of natural fibre, fibre loading direction, and resin flow direction on the tensile properties of developed composites are investigated. The longitudinal tensile strength of developed composites demonstrated a 7-8 fold increment, as compared to the transverse direction tensile strength. The flow along the fibre provides 10% increment in tensile strength due to higher permeability.
Keywords/Search Tags:Fibre, Tensile strength, Resin, Permeability
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