Kinetic Analysis and Characterization of Epoxy Resins ... - FedOA

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Experimental 90 Figure 2.23: Onset temperature of a fresh epoxy mixture, measured with a DSC dynamic scan at 10 ◦ C/min. 90
Experimental 91 2.6.3 Influence of the Mixture Thickness The thickness of the sample is another parameter investigated. This is a factor of great importance for the heat exchange and therefore for the curing process. The crosslinking reaction does not start for samples of thickness less than 1 mm, and also increasing the time of MW radiation the material appears sticky 27 . The reason seems to be, that quantity so small of epoxy resin absorbs very badly the MW radiation. While there is the hazard of thermal degradation of samples of thickness higher than 1 cm. Epoxy resin has a low thermal conductivity and therefore the energy dissipation is not efficient with mixture of high thickness. Finally a thickness of about 1-2 mm and a power of 1500 W, have been recognized as the best combination for ensuring a good energy transfer between the microwave radiation and the epoxy samples. 2.6.4 Influence of other parameters There are moreover other parameters, that can influence dielectric heating of a sample, some of these are reported below: • The geometry: samples of regular shape can be heated more quickly; • The moistness: the dielectric loss and so on the heating rate are higher when there is a great amount of water; • The ionic concentration: the presence of high ionic concentration increases the heating rate; • Phase transitions: phenomena like transition from ice to liquid water, crystallization, viscosity changes can modify significantly the capacity of a ma- 27 That is an indication of not complete conversion. 91
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UNIVERSITA’ DEGLI STUDI DI NAPOLI
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3 I thank all the lecturers of PhD
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5 Microwaves are electromagnetic ra
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CONTENTS 7 1.8.1 DielectricProperti
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CONTENTS 9 4 Conclusions and Outloo
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LIST OF TABLES 11 3.2 Average value
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List of Figures 1.1 Diglycidylether
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LIST OF FIGURES 15 2.23 Onset tempe
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LIST OF FIGURES 17 3.38 Comparison
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Introduction 19 cannot be melted an
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Introduction 21 • bismaleimides;
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Introduction 23 cold solders, casti
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Introduction 25 Average Properties
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Introduction 27 In Figure 1.4 n can
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Introduction 29 ducts and it genera
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Introduction 31 tween current-carry
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Introduction 33 that describe the p
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Introduction 35 1.3.5 Lorentz Force
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Introduction 37 Figure 1.11: Electr
Page 39 and 40: Introduction 39 Even microwaves can
Page 41 and 42: Introduction 41 production requirem
Page 43 and 44: Introduction 43 fect of the electro
Page 45 and 46: Introduction 45 following different
Page 47 and 48: Introduction 47 Debye equations bas
Page 49 and 50: Introduction 49 Although these mode
Page 51 and 52: Introduction 51 materials that have
Page 53 and 54: Chapter 2 Experimental In this chap
Page 55 and 56: Experimental 55 Characteristic Note
Page 57 and 58: Experimental 57 If the oven is used
Page 59 and 60: Experimental 59 In monomodal applic
Page 61 and 62: Experimental 61 Figure 2.5: Right s
Page 63 and 64: Experimental 63 Figure 2.8: Front v
Page 65 and 66: Experimental 65 regardless of the a
Page 67 and 68: Experimental 67 • The number of t
Page 69 and 70: Experimental 69 Figure 2.11: Surfac
Page 71 and 72: Experimental 71 Figure 2.12: Repeti
Page 73 and 74: Experimental 73 From the Figure 2.1
Page 75 and 76: Experimental 75 in the centre of th
Page 77 and 78: Experimental 77 not read the water
Page 79 and 80: Experimental 79 Test number 1 2 3 4
Page 81 and 82: Experimental 81 Figure 2.19: Plot o
Page 83 and 84: Experimental 83 2.5 Datalogger This
Page 85 and 86: Experimental 85 same reason a wood
Page 87 and 88: Experimental 87 Material Behaviour
Page 89: Experimental 89 in function of the
Page 93 and 94: Chapter 3 Results and Discussion Th
Page 95 and 96: Results and Discussion 95 There is
Page 97 and 98: Results and Discussion 97 Figure 3.
Page 99 and 100: Results and Discussion 99 Parameter
Page 101 and 102: Results and Discussion 101 After pr
Page 103 and 104: Results and Discussion 103 of insta
Page 105 and 106: Results and Discussion 105 1. Mecha
Page 107 and 108: Results and Discussion 107 where k
Page 109 and 110: Results and Discussion 109 Kinetic
Page 111 and 112: Results and Discussion 111 Figure 3
Page 113 and 114: Results and Discussion 113 3.3 Comp
Page 115 and 116: Results and Discussion 115 pedestal
Page 117 and 118: Results and Discussion 117 Tables 3
Page 123 and 124: Results and Discussion 123 t MW [s]
Page 125 and 126: Results and Discussion 125 simulate
Page 129 and 130: Results and Discussion 129 t DSC [s
Page 133 and 134: Results and Discussion 133 Using th
Page 135 and 136: Results and Discussion 135 forward
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Results and Discussion 141 than the
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Results and Discussion 143 Since ev
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Results and Discussion 145 ditions.
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Results and Discussion 147 3.23 and
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Results and Discussion 149 The T g
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Results and Discussion 151 3.6.1 St
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Results and Discussion 153 Flexural
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Results and Discussion 155 3.7.2 FT
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Results and Discussion 157 identifi
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Results and Discussion 159 This eff
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Results and Discussion 161 Also in
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Conclusions and Outlook 163 degree
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Appendix A A Brief History of Micro
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A Brief History of Microwave Oven 1
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Bibliography [1] W. Callister, “M
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BIBLIOGRAPHY 171 [19] P. I. Karkana
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BIBLIOGRAPHY 173 [34] K. D. V. Pras
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Kinetic Analysis and Characterization of Epoxy Resins ... - FedOA

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