 | Shayed M.A. Thermal and oxidation resistant barrier layers for textile high performance carbon materials by new coating systems. - Dresden: Techn. Univ. Dresden, 2014. - vii, 136, ix p.: ill., graph. - Bibliogr.: p.122-136. - ISBN 978-3-86780-416-5
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Symbols and Abbreviations ...................................... IV
1 Introduction ................................................. 1
1.1 General Introduction and state of the problems .......... 1
1.2 Outline of the thesis ................................... 4
2 Objectives of the thesis ..................................... 6
3 State of the art ............................................. 8
3.1 Textile high performance material from carbon fiber
(CF) .................................................... 8
3.1.1 Overview ......................................... 8
3.1.2 Structure of CF .................................. 8
3.1.3 CF manufacturing ................................. 8
3.1.3.1 CF from polyacrylonitrile (PAN) precursor .... 9
3.1.3.2 CF from mesophase pitch (MPP) precursor ..... 11
3.1.4 Properties of CF ................................ 12
Mechanical properties ........................... 12
Thermal properties .............................. 12
Electrical properties ........................... 13
Surface properties .............................. 13
3.2 Application of CF in composites ........................ 13
3.3 Coating systems for high temperature application ....... 16
3.3.1 Existing thermal and oxidation resistant
coating ......................................... 16
3.3.2 Existing coating processes ...................... 18
Physical vapor deposition (PVD) ................. 19
Chemical vapor deposition (CVD) ................. 19
Electroplating .................................. 20
Wet-chemical process ............................ 20
3.3.3 Coating polymers and fillers .................... 21
Polysilazane polymer ............................ 21
Polysiloxane polymer ............................ 22
Fillers in thermal resistant coating ............ 24
3.4 Thermal chemical and thermal physical testing
procedure .............................................. 24
Thermo gravimetric analysis (TGA) ...................... 24
Differential scanning calorimetry (DSC) ................ 25
Thermo-mechanical and fire testing methods ............. 25
Comparison of thermo-mechanical properties between
construction steel and CF .............................. 29
3.5 Conclusion ............................................. 30
4 Study on oxidation mechanism of CF .......................... 32
4.1 Oxidation kinetics and mechanism ....................... 32
4.2 Investigation of oxidation kinetics by TGA ............. 35
4.3 Conclusion ............................................. 37
5 New concepts for the enhancement of thermal and oxidation
resistance of CF ............................................ 39
6 Experimental ................................................ 42
6.1 Materials .............................................. 42
6.1.1 CF yarn substrate ............................... 42
6.1.2 Coating materials ............................... 42
6.1.2.1 Coating with polysilazane ................... 42
6.1.2.2 Coating with polysiloxane ................... 43
6.1.2.3 Tyranno® coating ............................ 45
6.1.2.4 Sol-gel coating ............................. 46
6.1.2.5 Filler materials ............................ 47
6.1.3 Chemicals and solvents .......................... 48
6.2 Coating procedure and working principle ................ 49
6.3 Coating formulations and parameters .................... 50
6.3.1 Single layer coating ............................ 51
6.3.2 Double layer coating ............................ 52
6.4 Characterization techniques ............................ 53
6.4.1 Thermal analysis ................................ 53
6.4.1.1 Thermo gravimetric analysis (TGA) ........... 53
6.4.1.2 Differential scanning calorimeter (DSC)
analysis .................................... 54
6.4.1.3 Thermal degradation analysis in muffle
oven ........................................ 54
6.4.2 Tensile test at room temperature and under
thermal stress .................................. 54
6.4.3 Alkali resistant test ........................... 56
6.4.4 Contact angle (CA) measurement and surface
energy (SE) calculation ......................... 56
6.4.5 Surface morphological analysis .................. 58
6.4.5.1 Scanning electron microscopy (SEM) .......... 58
6.4.5.2 Energy dispersive X-ray spectroscopy (EDX) .. 58
6.4.5.3 Infrared (IR)-spectroscopy .................. 59
6.4.5.4 X-ray photoelectron spectroscopy (XPS) ...... 60
6.4.5.5 Optical microscopy .......................... 61
7 Results and discussion ...................................... 62
7.1 Surface morphological analysis ......................... 62
7.1.1 SEM analysis .................................... 62
7.1.2 EDX analysis .................................... 65
7.1.3 XPS analysis .................................... 68
7.1.4 Infrared (IR) spectroscopy ...................... 70
7.1.5 Optical microscopy .............................. 72
7.2 Contact angle (CA) and surface energy (SE) results ..... 75
7.3 Thermal analysis ....................................... 77
7.3.1 Differential scanning calorimetry (DSC)
analysis ........................................ 77
7.3.2 TДrmo gravimetric analysis (TGA) ................ 78
7.3.3 Results of oxidation kinetic analysis ........... 89
7.3.4 Determination of mass loss at high temperature .. 94
7.3.5 Overall conclusion of thermal analysis results .. 97
7.4 Mechanical and thermo-mechanical properties ............ 98
7.5 Alkali resistant test results ......................... 109
8 Conclusion and outlook ..................................... 112
List of Figures ............................................ 116
List of Tables ............................................. 120
Bibliography ............................................... 122
A Appendix ..................................................... i
A.1 .......................................................... i
A.2 ......................................................... ii
A.3 ........................................................ iii
A.4 ......................................................... iv
A.5 .......................................................... v
A.6 ......................................................... vi
A.7 ........................................................ vii
A.8 ....................................................... viii
A.9 ......................................................... ix
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