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

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Experimental 86 2.6.1 Vessel Material The first parameter under investigation has been the material of the vessel containing the reacting mixture. The main requirement that the material must satisfy is the transparency to microwave. In fact these materials do not get warm directly, when radiated, and instead allow the absorption by the sample of the maximum quantity of the available energy. Materials reflecting the radiations, as metals, must be absolutely avoided. Moreover the vessel material must be inert to polymerization reactions and sufficiently resistant to high temperatures. The first qualitative tests have been performed using transparent commercial glasses of polystyrene (PS), a thermoplastic polymer with a T g ≈ 100 ◦ Canda T m ≈ 270 ◦ C. However in some cases during the curing process temperatures higher than 160 ◦ C have been reached. Therefore the PS vessel has undergone the glass transition, with consequent mechanical stability loss and following softening. For this reason vessels of PP have been chosen, because polypropylene is a thermoplastic polymer, microwave transparent, with a good thermal resistance 24 , and it preserves its mechanical properties up to the melting point at a temperature of about 180 ◦ C. However the best material for carrying out microwave experiments is polytetrafluoroethylene, because it microwave transparent, very non reactive, it has an elevated mechanical stability and excellent antiadhesive properties, but it is very expensive. In Table 2.7 a summary of the properties of some materials, when used as vessels for microwave experiments, is reported. Therefore the experiments for the kinetic analysis have been performed with PP cylindrical vessels of the size reported in Table 2.8. The vessels, placed on a glass pedestal of 2 cm of height, has been cut at about 4-5 cm of height for enabling 24 T g ≈−17 ◦ C. 86
Experimental 87 Material Behaviour Notes Metals Absorbing/Reflecting Hazard of electric discharges Glass Transparent Not reusable Cellulose Transparent/Absorbing Energy dissipation Polyethylene Transparent Low thermal resistance Polypropylene Transparent Suitable Polystyrene Transparent Low thermal resistance Table 2.7: Properties of some materials used as vessel for microwave experiments. the entrance inside the applicator cavity 25 . PP beaker Geometry Shape Volume Height Diameter Cylindrical 180 ml 8 cm 5 cm Table 2.8: Shape and size of the PP vessel used for microwave experiments. While experiments for the dynamical-mechanical characterization have been carried out with a polytethrafluoroethylene mould of geometry described in Table 2.9. 25 That is 10 cm height. 87
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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
Page 35 and 36: Introduction 35 1.3.5 Lorentz Force
Page 37 and 38: 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: Experimental 85 same reason a wood
Page 89 and 90: Experimental 89 in function of the
Page 91 and 92: Experimental 91 2.6.3 Influence of
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 137 Figure 3
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Results and Discussion 139 Figure 3
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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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