由於奈米碳管具有高剛度與高強度，它被視為最佳的複合材料的補強材。本研究使用環氧樹脂為基材並且加入不同直徑的多壁奈米碳管作為補強材，並討論複合材料在單軸拉伸下，碳管的重量百分比與直徑對於複合材料機械性質的影響。結果顯示在添加直徑為小於20奈米及介於40到60奈米的5 wt% 奈米碳管/環氧樹脂複合材料，其楊氏模數分別為4.56 GPa及4.36 GPa，抗拉強度分別為52.89 MPa與46.80 MPa，而純環氧樹脂的楊氏模數與抗拉強度分別為2.83 GPa及25.67 MPa。二種微觀力學模型-艾緖比與森田中-被推導用來預估多壁奈米碳管/環氧樹脂複合材料的彈性係數，並且與實驗結果比較。

Due to its excellent stiffness and strength, the carbon nanotube (CNT) is considered as an ideal candidate for reinforcement in composites. In the present work, the epoxy resin is used as the matrix whereas multi-walled carbon nanotubes (MWCNTs) with various diameters are used as the reinforcement. The composite is subjected to uniaxial tension and the effects of CNT weight fraction and CNT diameter on the mechanical properties of the composite are studied. The experiment results show that the Young modulus of 5 wt% CNT/epoxy composites with a CNT diameter D < 20 nm and D = 40 ~ 60 nm is 4.56 GPa and 4.36 GPa, and the tensile strength is 52.89 MPa and 46.80 MPa, respectively, whereas the Young modulus and the tensile strength of the pure epoxy is 2.83 GPa and 25.67 MPa, respectively. Micromechanics models are developed to predict the Young modulus of CNT-reinforced composites. The predicted Young moduli are benchmarked with the experimental data of MWCNT-reinforced epoxy-matrix composites.

TABLE OF CONTENTS

Abstract.............................................................i
Acknowledgments....................................................iii
List of Notations...................................................iv
Table of Contents...................................................vi
List of Tables......................................................ix
List of Figures......................................................x
Chapter 1 Introduction...............................................1
1.1 Background.............................................1
1.1.1 Composite Material...............................1
1.1.2 Categorization of Composite Materials............1
1.1.3 Applications of Composites.......................2
1.1.4 Carbon Nanotubes.................................2
1.1.5 Epoxy............................................3
1.2 Problem Statement......................................4
1.3 Literature Review......................................4
1.4 Objectives.............................................8
Chapter 2 Experiments...............................................13
2.1 Experimental Setup....................................13
2.1.1 Materials.......................................13
2.1.2 Facilities......................................13
2.2 Specimen Preparation..................................14
2.3 Tensile Test..........................................15
2.4 Experiment Result.....................................16
2.5 Microstructure Characterization.......................16
Chapter 3 Modeling..................................................46
3.1 Effective Properties..................................46
3.2 Homogenization........................................46
3.2.1 Eshelby’s Equivalent Inclusion Method..........46
3.2.2 Mori-Tanaka Method..............................47
3.3 Coordinate Transformation.............................48
3.3.1 Eshelby’s Model................................49
3.3.2 Mori-Tanaka’s Model............................50
3.4 Results...............................................50
3.4.1 Young’s modulus of MWCNT.......................50
3.4.2 Young’s modulus of MWCNT/epoxy composite.......51
Chapter 4 Conclusions...............................................57
Appendix A..........................................................58
Appendix B..........................................................59
References..........................................................61

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