The state of nanoclay dispersion in a molded epoxy disk and its effects on the thermomechanical properties of the resulting nanocomposite are analyzed. A commercially available nanoclay, Cloisite® 25A, is mechanically mixed at 2wt% with EPON 815C epoxy resin. The epoxy∕clay compound is then mixed with EPI-CURE 3282 curing agent by a custom made molding setup and injected into a disk shaped mold cavity. Upon completion of curing, nanoclay dispersion is quantified on a sample cut along the radius of the composite disk. Dispersion of nanoclay clusters larger than 1.5μm are analyzed by digital image processing of scanning electron micrographs taken radially along the sample, whereas dispersion at smaller scales is quantified by compositional analysis of clay via wavelength dispersive spectrometry (WDS). Digital images of the microstructure indicate that amount of nanoclay clusters that are larger than 1.5μm remain approximately constant along the radius. However, size analysis of nanoclay clusters revealed that they are broken down into finer clusters along the radius, possibly due to the high shear deformation induced through the thickness during mold filling. Compositional analysis by WDS signified that approximately 0.4wt% of the nanoclay is dispersed to particles smaller than 1.5μm, which are not visible in micrographs. Tensile and three-point bending tests are conducted on additional samples cut from the molded disks. Except for slight reduction in flexural strength, up to 9.5% increase in tensile strength, stiffness, and flexural modulus are observed. Glass transition temperature is determined under oscillatory torsion and observed to increase by 4.5% by the addition of nanoclay.

1.
Ahmadi
,
S. J.
,
Huang
,
Y. D.
, and
Li
,
W.
, 2004, “
Synthetic Routes, Properties and Future Applications of Polymer—Layered Silicate Nanocomposites
,”
J. Mater. Sci.
0022-2461,
39
(
6
), pp.
1919
1925
.
2.
Usuki
,
A.
,
Kawasumi
,
M.
,
Kojima
,
Y.
,
Okada
,
A.
,
Kurauchi
,
T.
, and
Kamigaito
,
O.
, 1993, “
Swelling Behavior of Montmorillonite Cation Exchanged for ω-Amino Acids by ε-Caprolactam
,”
J. Mater. Res.
0884-2914,
8
(
5
), pp.
1174
1178
.
3.
Usuki
,
A.
,
Kojima
,
Y.
,
Kawasumi
,
M.
,
Okada
,
A.
,
Fukushima
,
Y.
,
Kurauchi
,
T.
, and
Kamigaito
,
O.
, 1993, “
Synthesis of Nylon 6—Clay Hybrid
,”
J. Mater. Res.
0884-2914,
8
(
5
), pp.
1179
1184
.
4.
Kojima
,
Y.
,
Usuki
,
A.
,
Kawasumi
,
M.
,
Okada
,
A.
,
Fukushima
,
Y.
,
Kurauchi
,
T.
, and
Kamigaito
,
O.
, 1993, “
Mechanical Properties of Nylon 6—Clay Hybrid
,”
J. Mater. Res.
0884-2914,
8
(
5
), pp.
1185
1189
.
5.
Becker
,
O.
,
Sopade
,
P.
,
Bourdonnay
,
R.
,
Halley
,
P. J.
, and
Simon
,
G. P.
, 2003, “
Layered Silicate Nanocomposites Based on Various High-Functionality Epoxy Resins. Part II: The Influence of an Organoclay on the Rheological Behavior of Epoxy Prepolymers
,”
Polym. Eng. Sci.
0032-3888,
43
(
10
), pp.
1683
1690
.
6.
Dazhu
,
C.
, and
Pingsheng
,
H.
, 2003, “
Cure Behavior of Epoxy Resin—Montnorillonite—2-Ethyl-4-Methylimidazole Nanocomposite
,”
J. Compos. Mater.
0021-9983,
37
(
14
), pp.
1275
1287
.
7.
Jian
,
L.
,
Zhou
,
C.
,
Gang
,
W.
,
Wei
,
Y.
,
Ying
,
T.
, and
Qing
,
L.
, 2003, “
Preparation and Linear Rheological Behavior of Polypropylene∕MMT Nanocomposites
,”
Polym. Compos.
0272-8397,
24
(
3
), pp.
323
331
.
8.
Pinnavaia
,
T. J.
, and
Beall
,
G. W.
, 2001,
Polymer-Clay Nanocomposites
,
Wiley
,
Chichester
.
9.
Lan
,
T.
, and
Pinnavaia
,
T. J.
, 1994, “
Clay-Reinforced Epoxy Nanocomposites
,”
Chem. Mater.
0897-4756,
6
(
12
), pp.
2216
2219
.
10.
Pinnavaia
,
T. J.
,
Lan
,
T.
,
Kaviratna
,
P. D.
,
Wang
,
Z.
, and
Shi
,
H.
, 1995, “
Clay-Reinforced Epoxy Nanocomposites: Synthesis, Properties and Mechanism of Formation
,”
Polym. Mater. Sci. Eng.
0743-0515,
73
, pp.
117
118
.
11.
Wang
,
H.
,
Zeng
,
C.
,
Elkovitch
,
M.
,
Lee
,
L. J.
, and
Koelling
,
K. W.
, 2001, “
Processing and Properties of Polymeric Nano-Composites
,”
Polym. Eng. Sci.
0032-3888,
41
(
11
), pp.
2036
2046
.
12.
Abot
,
J. L.
,
Yasmin
,
A.
, and
Daniel
,
I. M.
, 2003, “
Mechanical and Thermoviscoelastic Behavior of Clay∕Epoxy Nanocomposites
,”
Mater. Res. Soc. Symp. Proc.
0272-9172,
740
, pp.
162
177
.
13.
Kinloch
,
A. J.
, and
Taylor
,
A. C.
, 2003, “
Mechanical and Fracture Properties of Epoxy/Inorganic Micro- and Nano-Composites
,”
J. Mater. Sci. Lett.
0261-8028,
22
(
20
), pp.
1439
1441
.
14.
Isik
,
I.
,
Yilmazer
,
U.
, and
Bayram
,
G.
, 2003, “
Impact Modified Epoxy∕Montmorillonite Nanocomposites: Synthesis and Characterization
,”
Polymer
0032-3861,
44
(
20
), pp.
6371
6377
.
15.
Becker
,
O.
,
Varley
,
R. J.
, and
Simon
,
G. P.
, 2003, “
Use of Layered Silicates to Supplementarily Toughen High Performance Epoxy—Carbon Fiber Composites
,”
J. Mater. Sci. Lett.
0261-8028,
22
(
20
), pp.
1411
1414
.
16.
Park
,
J. H.
, and
Jana
,
S. C.
, 2003, “
The Relationship Between Nano- and Micro-Structures and Mechanical Properties in PMMA-Epoxy-Nano Clay Composites
,”
Polymer
0032-3861,
44
(
7
), pp.
2091
2100
.
17.
Yasmin
,
A.
,
Abot
,
J. L.
, and
Daniel
,
I. M.
, 2003, “
Processing of Clay∕Epoxy Nanocomposites With a Three-Roll Mill Machine
,”
Mater. Res. Soc. Symp. Proc.
0272-9172,
740
, pp.
75
80
.
18.
Park
,
J.
, and
Jana
,
S. C.
, 2003, “
Epoxy-Aided Dispersion of Nanoclay in PMMA
,”
61st Annual Technical Conference-Society of Plastics Engineers
, Vol.
2
, pp.
1443
1447
.
19.
Park
,
J. H.
, and
Jana
,
S. C.
, 2003, “
Mechanism of Exfoliation of Nanoclay Particles in Epoxy-Clay Nanocomposites
,”
Macromolecules
0024-9297,
36
(
8
), pp.
2758
2768
.
20.
Pattanayak
,
A.
, and
Jana
,
S. C.
, 2003, “
A Study on Intercalation and Exfoliation of Layered Silicate Nanoparticles in Thermoplastic Polyurethanes
,”
61st Annual Technical Conference-Society of Plastics Engineers
, Vol.
2
, pp.
1424
1428
.
21.
Xu
,
W.
,
Bao
,
S.
, and
He
,
P.
, 2002, “
Intercalation and Exfoliation Behavior of Epoxy Resin∕Curing Agent∕Montmorillonite Nanocomposite
,”
J. Appl. Polym. Sci.
0021-8995,
84
(
4
), pp.
842
849
.
22.
Ratna
,
D.
,
Becker
,
O.
,
Krishnamurthy
,
R.
,
Simon
,
G. P.
, and
Varley
,
R. J.
, 2003, “
Nanocomposites Based on Epoxy Resin, Hyperbranched Epoxy Resin, and a Layered Silicate
,”
Polymer
0032-3861,
44
(
25
), pp.
7449
7457
.
23.
Kornmann
,
X.
,
Lindberg
,
H.
, and
Berglund
,
L. A.
, 2001, “
Synthesis of Epoxy-Clay Nanocomposites: Influence of The Nature of the Clay on Structure
,”
Polymer
0032-3861,
42
(
10
), pp.
1303
1310
.
24.
Bragg
,
W. H.
, and
Bragg
,
W. L.
, 1913, “
The Reflection of X-rays by Crystals
,”
Proc. R. Soc. London, Ser. A
0950-1207,
88
, pp.
428
438
.
25.
Wagener
,
R.
, and
Reisinger
,
T. J. G.
, 2003, “
A Rheological Method to Compare the Degree of Exfoliation of Nanocomposites
,”
Polymer
0032-3861,
44
(
24
), pp.
7513
7518
.
26.
Aktas
,
L.
,
Hamidi
,
Y. K.
, and
Altan
,
M. C.
, 2004, “
Characterisation of Nanoclay Dispersion in Resin Transfer Moulded Glass∕Nanoclay∕Epoxy Composites
,”
Plast. Rubber Compos.
1465-8011,
33
(
6
), pp.
267
272
.
27.
Parfitt
,
G. D.
, 1969,
Dispersion of Powders in Liquids: With Special Reference to Pigments
,
Elsevier
,
New York
.
28.
Montes
,
J. M.
,
Cintas
,
J.
,
Rodríguez
,
J. A.
, and
Herrera
,
E. J.
, 2003, “
Effective Pressure on Powders Under Uniaxial Compression
,”
J. Mater. Sci. Lett.
0261-8028,
22
(
23
), pp.
1669
1671
.
29.
Yang
,
M.
, and
Lin
,
S.
, 2003, “
A Method for Correcting the Contact Angle From the θ∕2 Method
,”
Colloids Surf., A
0927-7757,
220
, pp.
199
210
.
30.
Aktas
,
L.
,
Hamidi
,
Y. K.
, and
Altan
,
M. C.
, 2005, “
Wetting of Compacted Nanoclay Powder by Epoxy Resin
,”
Proceedings of ASME IMEC&E
, Paper No. 80381.
31.
Hamidi
,
K. Y.
,
Aktas
,
L.
, and
Altan
,
M. C.
, 2008, “
Effect of Nanoclay Content on Void Morphology in Resin Transfer Molded Composites
,”
Journal of Thermoplastic Composite Materials
,
21
(
2
), pp.
141
163
.
32.
Aktas
,
L.
,
Hamidi
,
Y. K.
, and
Altan
,
M. C.
, 2002, “
Effect of Moisture on The Mechanical Properties of Resin Transfer Molded Composites—Part I: Absorption
,”
J. Mater. Process. Manuf. Sci.
1062-0656,
10
(
4
), pp.
239
254
.
33.
Barraza
,
H. J.
,
Aktas
,
L.
,
Hamidi
,
Y. K.
,
Long
,
J.
,Jr.
,
O’Rear
,
E. A.
, and
Altan
,
M. C.
, 2003, “
Moisture Absorption and Wet-Adhesion Properties of Resin Transfer Molded (RTM) Composites Containing Elastomer-Coated Glass Fibers
,”
J. Adhes. Sci. Technol.
0169-4243,
17
(
2
), pp.
217
233
.
34.
Middleman
,
S.
, 1977,
Fundamentals of Polymer Processing
,
McGraw-Hill
,
New York
.
35.
Olivero
,
K. A.
,
Barraza
,
H. J.
,
O’Rear
,
E. A.
, and
Altan
,
M. C.
, 2002, “
Effect of Injection Rate and Post-Fill Cure Pressure on Properties of Resin Transfer Molded Disks
,”
J. Compos. Mater.
0021-9983,
36
(
16
), pp.
2011
2028
.
36.
Altan
,
M. C.
, and
Rao
,
B. N.
, 1995, “
Closed-Form Solution for the Orientation Field in a Center-Gated Disk
,”
J. Rheol.
0148-6055,
39
(
3
), pp.
581
599
.
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