Online Thesis Search Results

TITLE
DEDICATION
CERTIFICATE 1
CERTIFICATE-2
DECLARATION
ACKNOWLEDGEMENT
GLOSSARY OF TERMS
CONTENTS
1. INTRODUCTION
1.1. Introduction
Fig 1.1 Cumulative plastics growth by market (Source: Ref. IJ
1.2. Classification of composites
1.2.1 Particulate composites
1.2.2 Fibre reinforced composites
1.2.3 Laminated composites
1.2.4 Hybrid composites
Fig. 1.4. Idealised stress-strain characteristics of sandwich hybrid (Source: Ref. 11)
1.3. Fibres
1.3.1 Man-made fibres
1.3.1.1 Regenerated fibres
1.3.1.2 Synthetic fibres
Scheme 1.2. Classification of fibres
1.3.2 Natural fibres
1.3.2.1 Mineral fibres
1.3.2.2 Animal fibres
1.3.2.3 Plant fibres
Fig. 7.5. Cross-section of sisal fibre showing the distribution of cells of different sizesand shapes with thick cell wall,
1.4. Matrices
Fig. 1.6. Cumulative domestic thermoset growth (Source: Ref. l)
Fig. 1.7. Cumulative domestic thermoplastic growth (Source: Ref. 1)
1.5. Interface
1.6. Fabrication techniques
Scheme 1.3. Different moulding techniques
1.7. Factors influencing the composite properties
1.7.1 Strength, modulus and chemical stability of the fibre and the polymer matrix
1.7.2 Influence of fibre orientation and volume fraction
Fig. 1.6 Schematic represenbtions of (a) continuous and aligned and (b) discontinuousand randomly oriented fibre-reinforced composites.
1.7.3 Influence of fibre length
Fig. 1.11. Diagrams of tensile stress applied to discontinuous fibres of different lengths.
Fig. 1.12. Diagrams of (a) tensile stress (a) applied to fibre of length (I) and (b) shearstress (r) applied at the interface.
1.7.4 Influence of voids
1.7.5 Coupling agents
1.8. Interface modification
1.8.1 Surface modification of polymers
1.8.2 Surface modification of fibres
1.9. Characterisation of interface
1.10. Natural fibre reinforced polymer composites and their applications
Fig. 7.13. Possibilities of use for natural fibres in automobiles
1.11. Hybrid composites of natural fibres with synthetic fibres
1.12. Scope and objectives of the work
1.13. References
2. MATERIALS AND EXPERIMENTAL TECHNIQUES
2.1. Materials
2.1.1 Sisal fibre
Table 2.1. Physical characteristics and mechanical properlies of sisal fibre.
Table 2.2. Chemical constituents of sisal fibre.
2.1.2 Glass fibre
2.1.3 Polyethylene
2.1.4 Chemicals
2.2. Chemical modifications
2.2.1 Sodium hydroxide treatment
2.2.2 Acetylation (using acetic anhydride)
2.2.3 Permanganate (KMnO4) treatment
2.2.4 Stearic acid treatment
2.2.5 Peroxide treatment
2.2.6 Silane (A 174) treatment
2.2.7 Maleic anhydride modification
2.3. Characterisation
2.3.1 IR spectroscopy
2.3.2 Scanning electron microscopy
2.3.3 Optical microscopy
2.4. Preparation of composites
Fig. 2.1 Schematic process diagram of steps involved in compression mouldingof oriented composites: (a) leaky mould, (b) extrudates with orientedfibres, (c) exbudatas in the mould, (d) application of pressure and (e) release of product.
2.5. Characterisation of composite properties
2.5.1 Mechanical properties
2.5.2 Rheological measurements
2.5.3 Thermogravimetric analysis
2.5.4 Dynamic mechanical analysis
2.5.5 Thermal conductivity analysis
Fig. 23. (a) Block diagram of the experimental TPS set-up at low temperature, where DVM is a digital voltmeter and GPlB is a general purpose interfacebus, (b) vertical section through the cryostat, (c) sample holder and (d) shape of the sample.
Fig. 2.4. The photograph of the TPS experimental setup
Fig. 2.5. The bridge circuit used to monitor the voltage variation U (t)
2.5.6 Electrical properties
2.5.7 Thermal and water ageing studies
2.6. References
3. INFLUENCE OF RELATIVE VOLUME FRACTION, INTIMATELY MIXED ORIENTATION AND HYBRIDEFFECT ON THE MECHANICAL PROPERTIES OFSHORT SISAL/GLASS HYBRID FIBRE REINFORCEDLOW DENSITY POLYETHYLENE COMPOSITES
3.1. Introduction
3.2. Results and discussion
Fig.3.10. Opfical micrographs of the cross-section of (a) GRP, (b) SRP, (c) GSRPcontaining 0.3 volume fraction of GRP and (d) GSRP containing 0.6 volumefraction of GRP (Magnification X 60)
Fig. 3.17. Scanning electron micrograph of fracture surface of GSRP (50150 compositionof SRPIGRP) composites containing untreated fibres.
Fig. 3.27. Photomicrographs of the failure surfaces of flexural tested (a) SRP (Vi sisal =0.741, (b) GSRP (Vi sisal: Vf of glass = 0.14: 0.05) and (c) GRP (Vi of gkss =0.14)
3.2.1 Comparison with theoretical predictions
3.2.2 Hybrid effect calculation
3.3. References
4. HYBRID EFFECT IN TENSILE AND FLEXURALPROPERTIES OF SHORT SISAL/GLASS HYBRIDFIBRE REINFORCED LOW DENSITYPOLY ETHYLENE SANDWICH COMPOSITES
4.1. Introduction
4.2. Results and discussion
Fig. 4.8. Scanning electron micrographs of tensile fracture surfaces of (a) GSG and (b) SGS at 50150 composition of SRP and GRP
Fig. 4.9. Scanning electron micrograph of the cross section of SGS sandwich compositecontaining 50150 composition of SRPIGRP
Fig. 4.79. Optical Photomicrographs of tensile side of the tlexural fracture surfaces of (a) GSG, (b) SGS and (c) GSRP at 50/50 composition of SRP and GRP
Table 4.1. Water uptake values of composites
4.3. References
5. EFFECT OF FIBRE LENGTH AND CHEMICALMODIFICATIONS ON THE TENSILE PROPERTIESOF INTIMATELY MIXED SHORT SISAL/GLASSHYBRID FIBRE REINFORCED LOW DENSITYPOLYETHYLENE COMPOSITES
5.1. Introduction
5.2. Results and discussion
5.2.1 Fibre length distribution
5.2.2 Tensile properties
5.2.2.1 Effect of fibre length
5.2.2.2 Effect of composition of fibres
5.2.2.3 Effect of chemical modifications
(a) Effect of sodium hydroxide treatment (NaOfl
Fig. 5.5. SEM photographs of (a) untreated and (b) alkali treated sisal fibre.
Fig. 5.6. SEM photographs of tensile fracture surfaces of (a) untreated and (6) alkalitreated GSRP (50/50 SRPIGRP) composites
(b) Effect of acelylation ojsi.salfires
Fig. 5.8. SEM photograph of acetic anhydride treated sisal fibre
Fig. 5.10. SEM photographs of tensile fncture surfaces of acetic anhydride treated GSRP (50150 SRPIGRP) composites
(c) Effect of stearic acid treatment
Fig. 5.12. SEM photographs of tensile fracture surfaces of stearic acid treated GSRP (50/50) composites
(d) Effect of permanganate treatment (KMnO, )
Fig. 5.14. SEM photograph of permanganatetreated sisal fibre
Fig. 5.15. SEM photographs of tensile fracture surfaces of KMn04 treated GSRP (50/50SRPIGRP) composites
(e) Eflect of Maleic anhydride modifications (MAPE)
Fig. 5.19. SEM photographs of tensile fracture surfaces of MAP€ modified GSRP (50150SRPIGRP) composites
(f) Effect ofsiklne treatment
Fig. 5.23. SEM photographs of tensile fracture surfaces of silane treated GSRP (50150SRPIGRP) composites
(g) Effect of peroxide [dicumyl (DCP) and benzoyl peroxide (UPO) ]treatment
Fig. 5.25. SEM photographs of tensile fracture surfaces of DCP treated GSRP (50150SRPIGRP) composites
Fig. 5.26. SEM photographs of tensile fracture surfaces of BP0 treated GSRP (50/50SRPIG RP) composites
(h) Comparative efficiency of dqferent treatments
5.3. References
6. THEORETICAL MODELLING OF TENSILE PROPERTIES OF SHORT SISAL, GLASS, INTIMATELY MIXED SISAL/GLASS HYBRID FIBREREINFORCED LOW DENSITY POLYETHYLENECOMPOSITES
6.1. Introduction
6.2. Theory
6.2.1 Theories of rigid particulate reinforcement in non-rigid polymer matrices
6.2.1.1 Einstein and Guth equations
6.2.1.2 Modified Guth equation
6.2.1.3 Modified Kerner equation
6.2.2 The theories of rigid reinforcement (Particulate and fibrous) in rigid matrix
6.2.2.1 Parallel and series models
6.2.2.2 Hirsch model
Fig. 6.1. A schematic representation of Hirsch model
6.2.2.3 The Halpin-Tsai model
6.2.2.4 Modified Halpin-Tsai equation
6.2.2.5 Cox model
6.2.2.6 Modified Bowyer and Bader model
6.2.2.7 Additive rule of hybrid mixture
6.3. Results and discussion
Fig. 6.9. Photographs of (a) kngitudinally and (b) randomly oriented SRP (20% sisal) composites
Fig. 6.13. Optical micrograph of sisaULDPE (SRP) composites showing transcrystallinity (Source: Ref. 38)
6.4. References
7. MELT RHEOLOGICAL BEHAVIOUR OFINTIMATELY MIXED SHORT SISAL/GLASS HYBRIDFIBRE REINFORCED LOW DENSITYPOLYETHYLENE COMPOSITES
7.1. Introduction
7.2. Results and discussion
7.2.1 Effect of shear rate and relative composition of fibres on viscosity
7.2.2 Effect of shear stress and relative composition of fibres on viscosity
7.2.3 Effect of chemical modifications
7.2.4 Effect of temperature
7.2.5 Shear stress-temperature super position master curve
7.2.6 Hybrid effect calculation
7.2.7 Fibre breakage analysis
7.2.8 Die swell ratio
7.2.9 Extrudate characteristics
Fig. 7.11. Optical photomicrograph of the extrudates at two different shear rates: A, B, C, D, E, F, G, H indicate ihe LDPE, SRP (20% sisal), GSRP (80120, 60/40, 50/50, 40/60, 20/80 compositions of SRP/GRP) and GRP (20% glass) respectively
Fig. 7.12. Optical photomicrograph of the GSRP (50/50 SRP/GRP) extrudafes at a singleshear rate: A, B, C, D, E, F, G, H, I indicate the untreated, alkall, acetic anhydride, stearic acid, KMn04 maleic anhydride, silane, DCP and BP0 respectively
Fig. 7.13. Scanning electron micrographs of the surfaces of the extrudates (a) LDPE, (b) SRP (20% sisal), (c) GSRP (40/60 SRPIGRP) and (d) GRP (20% glass)
Fig. 7.14. Scanning electron micrographs of the cross-section of the extrudates (a) LDPE, (b) SRP (20% sisal), (c) GSRP (80120 SRPIGRP), (d) GSRP (50I50 SRPIGRP), (e) GSRP (20I80 SRPIGRP) and (f) GRP (20% glass)
7.2.10 Flow behaviour index n
7.3. References
8. THERMOGRAVIMETRIC AND DYNAMICMECHANICAL ANALYSIS OF INTIMATELY MIXEDSHORT SISAL/GLASS HYBRID FIBRE REINFORCEDLOW DENSITY POLYETHYLENE COMPOSITES
8.1. Introduction
8.2. Results and discussion
8.2.1 Thermogravimetric analysis
8.2.2 Dynamic mechanical analysis
8.2.2.1 Effect of composition
8.2.2.2 Effect of chemical modifications
8.2.2.3 Effect of frequency
8.3. References
9. THERMAL CONDUCTIVITY AND THERMALDIFFUSIVITY MEASUREMENTS IN SISAL FIBRE, GLASS FIBRE AND INTIMATELY MIXEDSISAL/GLASS HYBRID FIBRE REINFORCED LOWDENSITY POLYETHYLENE COMPOSITES
9.1. Introduction
9.2. Modeling of thermal conductivity
9.3. Results and discussion
9.3.1 Thermal conductivity measurements
9.3.1.1 Effects of composition of fibres
9.3.2 Effect of fibre orientation
9.3.3 Thermal diffusivity measurements
9.4. Reference
10. ELECTRICAL PROPERTIES OF INTIMATELY MIXEDSHORT SISAL/GLASS HYBRID FIBRE REINFORCEDLOW DENSITY POLYETHYLENE COMPOSITES
10.1. Introduction
10.2. Results and discussion
10.2.1 Dielectric constant
(a) Effect offibre length
(b) Effect of relative composition of skul und glussfibres
(c) Effe of chemical modifications
10.2.2 Volume resistivity
10.2.3 Conductivity
10.2.4 Dissipation factor
10.3. References
11. EFFECT OF AGEING ON THE PROPERTIES OFINTIMATELY MIXED SHORT SISAL/GLASS HYBRIDFIBRE REINFORCED LOW DENSITYPOLY ETHYLENE COMPOSITES
11.1. Introduction
11.2. Results and discussion
11.2.1 Effect of ageing on untreated composites
Fig. 11.7. Scanning electron micrographs of aged GSRP (50150 SRPIGRP) samples: (a) exposure in boiling water after 7 h and (b) exposure at elevated temperatureaff er 7 days
11.2.2 Effect of ageing on treated composites
11.3. References
COST EFFECTIVENESS ANDPRODUCT DEVELOPMENT
Photograph of cupboard manufactured from sisaUglasslPE hybrid composite
CONCLUSIONS
List of Publications
INTERNATIONAL PLASTICS ENGINEERING AND TECHNOLOGY VOL 1. 87-98 (1995)
HYBRID FIBRE REINFORCED POLYMERCOMPOSITES
Hybrid Effect in the MechanicalProperties of Short SisalIGlass HybridFiber Reinforced Low DensityPolyethylene Composites
Influence of Short Glass Fiber Additionon the Mechanical Properties of SisalReinforced Low DensityPolyethylene Composites
Theoretical modelling of tensile properties of shortsisal fibre-reinforced low-density polyethylenecomposites