Studying the Effects of Functionalized Multi-walled Carbon Nanotubes on Mechanical and Thermal Properties of Epoxy Composites

Nasim Hadiashar1, Prashanth Asuri1, Navid Babhadiashar2

1Department of Bioengineering, Santa Clara University, Santa Clara, CA

2Thermo Fisher Scientific, Santa Clara, CA

Outline

Introduction

Purpose of the study

Advantages of using Epoxy composite

Functionalization of Multi-walled Carbon Nanotubes (MWCNTs)

Experimental Results and Conclusions

Advantages of using Epoxy composites

– High strength

– High stiffness

– Low weight

– Corrosion resistance

Elements of the Epoxy Resin

1. 40% High viscosity Epon 828

2. 60% Low viscosity Epon 1001F

3. 10% Curing agent Dyhard D50EP

4. 2% Hardener Dicy UR-500

Epoxy composites

Advantages of using MWCNTs

– Known to improve mechanical properties of a variety of materials (e.g. polymers, elastomers, etc.)

– Fabricating lighter composites

Disdvantages of using MWCNTs

– High cost

– Poor dispersion and interfacial bonding with the bulk materials

– Agglomeration at higher concentrations

Multi-walled Carbon Nanotubes (MWCNTs)

Functionalization of MWCNTs

Advantages: improves compatibility between bulk matrix and MWCNTs

Method

a. Acid treatment

b. Covalent functionalization with amine or carboxyl groups

Experimental Results

Thermogravimetric analysis

Experimental Results

Onset decomposition temperature

Sample5 °C/min 10 °C/min 20 °C/min

To (°C) Tp (°C) ΔΗ (J/g) To (°C) Tp (°C) ΔΗ (J/g) To (°C) Tp (°C) ΔΗ (J/g)

Neat 119 132 336 131 144 326 143 158 301

1 wt% Amine- MWCNTs

120 133 316 132 144.5 327 144 157 308

1 wt% Carboxyl- MWCNTs

123 134 321 133 145.5 330 146 159.5 326

1 wt% Raw MWCNTs

119.5 132 293.6 130 142.5 314.2 141 154 286

Experimental Results

Differential scanning calorimetry (DSC)

Experiments for Neat, 1 wt% Amine-MWCNTs, 1 wt% Carboxyl-MWCNTs, and 1 wt% Raw MWCNTs samples carried out at different heating rates of 5, 10, and 20 °C/min.

Experimental Results

Tensile testing

Experimental Results

Young’s Modulus testing

Conclusions

Amine/carboxyl-functionalized MWCNTs lead to

better improvements in relative to raw MWCNTs

Raw MWCNT samples showed a marked

decrease in epoxy mechanical properties

Optimum loading of functionalized MWCNTs is

less than 0.5 wt%