Conferencia sobre el comportamiento tribologico del polimero ABS reforzado con nanotubos de carbon.

1. OCTOBER 2013
“On the tribological perfomance of carbon nanotubes
reinforced Acrilonitrile-Butadiene-Styrene polymer”
Reyes-Reyes J. L. 1, Chiñas-Castillo F. 1, Sánchez Rubio M. 1
& Lara-Romero J. 2 & Hüirache Acuña R. 2
1 Instituto Tecnológico de Oaxaca, Department of Mechanical Engineering
2 Universidad Michoacana de San Nicolás de Hidalgo, Department of Chemical Engineering
CONTACT:
fernandochinas@gmail.com
rerjl@gmail.com

2. Introduction
In this study the tribological effect of adding CNTs in ABS
thermoplastic matrix through melted compounding technique is
presented. Friction and wear performance of the nanocomposite
were investigated on a pin-on-disc tribometer for a range of
loads. Addition of up to 0.5%wt CNTs into the ABS matrix highly
increased the wear resistance and nanoindentation tests
indicate a significant improvement in Young’s modulus and
hardness. The worn surface of ABS/CNTs nanocomposites was
examined with SEM and optical microscopy showing that the
wear mechanism shifted from abrasive wear in ABS matrix to
adhesion and small delamination wear for the nanocomposite.
ABS/CNTs nanocomposites with a low content of CNTs are a
candidate material for engineering application.

3. Methods and materials
Carbon nanotubes were prepared by spray pyrolysis as
described in reference [5]. Commercially available ABS
general propose MG47 (medium impact) was
purchased from plastic GE. A pin-on-disc tribometer
was used for this study to perform wear tests according
to ASTM G99-95a. Measurements of hardness and
modulus of elasticity were obtained by a nanoindenter
Hysitron Ubil.
[5] J. Robles–Nuñez, F. Chiñas-Castillo, M. Sanchez-Rubio. J. Lara-Romero, R. Huirache-Acuña, S. Jimenez-Sandoval, and G. Alonso-Nuñez, ”Improved hydrothermal synthesis
of MoS2 sheathed carbon nanotubes”, Chemical paper, Vol. 66, No. 12 pp. 1130-1136 (2012)

4. Methods and materials
The CNTs were added as prepared. ABS pellets and
CNTs were mixed in a mechanical mono screw extruder.
A higher dispersion was obtained after a second
extrusion of ABS+CNT. The resultant product went
through a moulding injection process to get
nanocomposite disc samples of 10 mm thickness and
25.4 mm in diameter. For tribological tests 6 mm diam.
AISI52100 steel balls were used.
MWCNTs
ABS
MATRIX

5. Methods and materials
Pellets ABS (virgin)
Mini pellet mill
MWCNTs
Dried
Bands
Hopper
Filaments of ABS
Next
ABS Pellets
ABS+0.1% MWCNTs
ABS+0.5% MWCNTs

6. Methods and materials
Pellets ABS in Hopper
ABS
MATRIX
ABS+0.1% MWCNTs
ABS+0.3% MWCNTs
ABS+0.5% MWCNTs
ABS + CNT NANOCOMPOSITES

7. TEM of ABS+CNTs nanocomposites

8. FT-IR Spectra of ABS and ABS+CNTs
• Benzene ring (3062, 3028,1603-1453,
760-699 cm -1)
• Nitrile (2238 cm -1)
• Methylene (2921 & 2851 cm -1)

9. Elastic modulus of ABS and ABS+CNTs

10. Hardness of ABS and ABS+CNTs

11. Tribometer “pin-on-disc”
Test conditions
•
•
•
•
Load
Constant speed
Time
Temperature
5, 10 & 12 N
0.4 m/s
60 min
Ambient

12. Friction coefficient and wear ABS matrix
As load increases from 5 - 12N wear increases and friction coefficient decreases.

13. Wear of ABS matrix vs. nanocomposites

14. Wear of ABS matrix and nanocomposites

15. SEM images of wear track (load 5N)
Sliding direction
Wear abrasive
ABS matrix
Cracks
ABS+0.1 CNTs
Deformation plastic
and adhesion
ABS+0.3 CNTs
ABS+0.5 CNTs
Fatigue-Delamination

16. SEM images of wear track (load 12N)
Plastic flow
ABS matrix
Wear abrasive
Cracks
ABS+0.1 CNTs
Adhesion and
Delamination-Fatigue
ABS+0.3 CNTs
Plastic
Deformation and
flow
ABS+0.5 CNTs

17. Conclusions
• Hardness and elastic modulus is HIGHER with higher CNTs content.
• Wear is REDUCED with higher CNTs content.
• Wear mechanism is shifted from abrasion to adhesion and delamination
with higher CNTs content.
• Higher content of CNTs reduces wear debris, increasing cohesion force of
the polymer.
• For ABS friction is REDUCED as load is higher
• Adding CNTs to ABS causes friction to pass a transition from elastic contact
to plastic one. Load can vary the temperature of visco-elastic transitions in
polymers and thereby the mechanism of friction.