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Processing and Mechanical Characterization of Glass Fiber Reinforcements
using GO Nano Particles
Rehan Umer Aerospace Engineering Department
Khalifa University, Abu Dhabi, UAE. [email protected]
Introduction Recently, a new 2D material graphene, has triggered numerous fundamental and technological studies. Much like CNTs, graphene demonstrates excellent electrical and thermal conductivity with good mechanical properties. Also, the production cost of graphene can be much lower than CNTs. Derived from its excellent flexibility and large interfacial area, the graphene sheets may serve as suitable fillers for the enhancement of mechanical and electrical properties in composites materials.
Objective The objective of this research is to investigate the processing and mechanical properties of graphene oxide (GO) nano particle reinforced glass fiber composites using LCM processing.
Methodology GO was synthesized from graphite powder by the modified Hummers method . The graphite oxide suspension was diluted to 5 mg/ml, and was then mixed with epoxy resin (Prime 20 LV) using ultrasonication and mechanical stirring. Three different percentages of GO (0.05, 0.1 and 0.2%) were obtained. The samples were tested for viscosity and DSC. After that, samples were prepared using the VARTM process. Coupons were cut and were subjected to flexure and low velocity impact tests.
Results
Conclusions
Figure 5: Summary of the mechanical characterization tests (a) flexural strength, (b) low velocity impact response.
Figure 2: DSC scans (a) Dynamic scan, (b) Degree of cure vs time
Figure 4: VARTM manufacturing (a) photos of flow front progression, (b) flow front position vs time.
The addition of graphene oxide to the neat epoxy resin system increased the viscosity, hence mold filling times increased. On the other hand, the addition of GO particles effected the curing behavior of the resin, causing premature gelation, hence reducing the processing window at higher GO content. The mechanical test results show promising results, an increase in flexural strength was noted. The low velocity impact was also improved at higher GO content.
0
5
10
15
20
25
30
0 500 1000 1500 2000
Flow
Fro
nt P
ositi
on (c
m)
Time (s)
0% GO0.05% GO0.1% GO0.2% GO
-0.15
-0.1
-0.05
0
0.05
0.1
0.15
0.2
0.25
0 50 100 150 200 250
Hea
t Flo
w (W
/g)
Temperature (oC)
0% GO0.2% GO
0.00
1.00
2.00
3.00
4.00
5.00
6.00
0 100 200 300 400 500 600
Visc
osity
(Pa.
s)
Time (s)
0% GO0.05% GO0.1% GO0.2% GO
0
500
1000
1500
2000
2500
0 2 4 6 8 10
Pea
k L
oad
(N)
Impact Energy (J)
0.2% GO
0% GO
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
20 30 40 50 60 70 80 90 100
Vis
cosi
ty (P
a.s)
Temperature (oC)
0% GO0.05% GO0.1% GO0.2% GO
0
100
200
300
400
500
600
700
Glass/GO Epoxy Composites
Flex
ural
Str
engt
h (M
Pa)
0% GO
0.05% GO
0.1% GO
0.2% GO
Figure 3: Viscosity measurements (a) Isothermal scan at 80oC (b) temperature sweep
0
0.2
0.4
0.6
0.8
1
0 5 10 15 20 25 30
Deg
ree
of C
ure
Time (min)
0% GO0.05% GO0.1% GO0.2% GO
Pure Epoxy 0.1% GO 0.2% GO 0.05% GO 0% GO
• DSC and Resin Rheology
Figure 1: Glass/GO epoxy composites
(b)
(a)
(a)
(b)
• VARTM processing
(b)
(a)
• Flexural Strength and Low Velocity Impact Response
(a) (b)
