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

More documents

Recommendations

Info

Results and Discussion 116 Time for the Epoxy System Complete Conversion at Different Powers P[W] t[s] 1000 350 1500 175 2000 100 Table 3.9: Time required for the complete conversion of the epoxy system during MW cure processes at different radiation powers. example the signal obtained with a fragment of the sample cured for 175 s with a power of 1500 W is illustrated in Figure 3.13. Figure 3.13: DSC dynamic scan of sample microwave cured for 175 s at 1500 W. At every power, partial microwave cure processes have been performed, for time less than that required for a complete conversion and selected in a way to obtain a representative trend of fractional degree of cure. After these time the residual enthalpy of the sample (∆H RES ) has been measured with a DSC dynamic scan between 0 and 250 ◦ Cwithasof10 ◦ C/min. These data have been listed in 116
Results and Discussion 117 Tables 3.10, 3.11 and 3.12. Residual Enthalpy versus Time for P = 1000 W Time [s] ∆H RES [J/g] 100 415,7 150 349,1 200 139,1 250 86,07 300 9,48 350 ≈ 0 Table 3.10: Residual enthalpy against time during MW cure process at 1000 W. In every case a sharp decrease of residual enthalpy is observed after a time depending on the heating rate and, therefore on the radiation power. For example in Figure 3.14 the residual enthalpy after a microwave cure process at 1500 W for 125 s is shown. During these partial crosslinking reactions the sample temperatures have been recorded every 0,5 s by datalogger 10 . For a clearer representation of the data, only the temperatures corresponding to the time, chosen for the residual enthalpy measurement, have been plotted. The thermal profile, followed by the system during the cure process at the power of 1000 W, illustrated in Figure 3.15, is not reproducible with a simple DSC dynamic scan and therefore, at least for the comparison between MW and DSC, has been discarded. While the thermal profiles during the cure at 1500 W and 2000 W are well comparable with DSC dynamic scan, respectively at 44 and 70 ◦ C/min, at least for the main part of the reaction 10 Described in the section 2.5 on page 83. 117
Page 1 and 2:
UNIVERSITA’ DEGLI STUDI DI NAPOLI
Page 3 and 4:
3 I thank all the lecturers of PhD
Page 5 and 6:
5 Microwaves are electromagnetic ra
Page 7 and 8:
CONTENTS 7 1.8.1 DielectricProperti
Page 9 and 10:
CONTENTS 9 4 Conclusions and Outloo
Page 11 and 12:
LIST OF TABLES 11 3.2 Average value
Page 13 and 14:
List of Figures 1.1 Diglycidylether
Page 15 and 16:
LIST OF FIGURES 15 2.23 Onset tempe
Page 17 and 18:
LIST OF FIGURES 17 3.38 Comparison
Page 19 and 20:
Introduction 19 cannot be melted an
Page 21 and 22:
Introduction 21 • bismaleimides;
Page 23 and 24:
Introduction 23 cold solders, casti
Page 25 and 26:
Introduction 25 Average Properties
Page 27 and 28:
Introduction 27 In Figure 1.4 n can
Page 29 and 30:
Introduction 29 ducts and it genera
Page 31 and 32:
Introduction 31 tween current-carry
Page 33 and 34:
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 and 86: Experimental 85 same reason a wood
Page 87 and 88: Experimental 87 Material Behaviour
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: Results and Discussion 115 pedestal
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
Page 141 and 142: Results and Discussion 141 than the
Page 143 and 144: Results and Discussion 143 Since ev
Page 145 and 146: Results and Discussion 145 ditions.
Page 147 and 148: Results and Discussion 147 3.23 and
Page 149 and 150: Results and Discussion 149 The T g
Page 151 and 152: Results and Discussion 151 3.6.1 St
Page 153 and 154: Results and Discussion 153 Flexural
Page 155 and 156: Results and Discussion 155 3.7.2 FT
Page 157 and 158: Results and Discussion 157 identifi
Page 159 and 160: Results and Discussion 159 This eff
Page 161 and 162: Results and Discussion 161 Also in
Page 163 and 164: Conclusions and Outlook 163 degree
Page 165 and 166: Appendix A A Brief History of Micro
Page 167 and 168:
A Brief History of Microwave Oven 1
Page 169 and 170:
Bibliography [1] W. Callister, “M
Page 171 and 172:
BIBLIOGRAPHY 171 [19] P. I. Karkana
Page 173:
BIBLIOGRAPHY 173 [34] K. D. V. Pras
show all

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

Create successful ePaper yourself

Delete template?

Save as template?