hnology Bhanu Bhattarai -
Mechanical properties of nanoclay based nanocomposites: a review
August 7, 2006
Dr. Christopher C Ibeh, Director
2006 PSU CNCMM REU/RET
Professor, Plastics Engineering Technology
Pittsburg State University
RE: Mechanical properties of nanoclay based nanocomposites: a review
Dear Dr. Ibeh:
I am very pleased to inform you that I have completed the above stated project.
The main objective of this report is to review different published articles in regard to the
mechanical properties of nanoclay based nanocomposites.
I hope this report will meet with your approval. If you have any other information about my
review, Ill supply it for you upon your request. If you have any questions or comments, I can be
reached at bhanubhattarai@hotmail.com
Sincerely,
Bhanu Bhattarai
Cc: Stefano Bietto Bhanu Bhattarai -
Mechanical properties of nanoclay based nanocomposites: a review
Mechanical properties of nanoclay based
nanocomposites: a review
August 7, 2006
PSU CNCMM REU/RET
Bhanu Bhattarai
MBA Accounting
Pittsburg State University
Submitted to:
Dr. Christopher C. Ibeh
Director of CNCMM
Professor, Plastics Engineering Technology
Pittsburg State University
Advisor
Stefano Bietto Bhanu Bhattarai -
Mechanical properties of nanoclay based nanocomposites: a review
Table of Content
Abstract
2
Introduction
2
Literature Review
3
Mechanical properties of nanoclay based nanocomposites
4
Methodology
32
Results and Evidence
34
Discussion of Results
38
Conclusions
38
Recommendations
39
References
39
Acknowledgement
40 Bhanu Bhattarai -
Mechanical properties of nanoclay based nanocomposites: a review
Mechanical properties of nanoclay based nanocomposites: a review
Abstract
In this study a review of different properties of nanocomposites containing nanoclay is made.
The study will be focused sharply on the mechanical properties, like Tensile strength, Stress strain,
Flexural properties, Young Modulus of different nanocomposites with an intention to create an online
data base system. Different scientific journals and articles will be reviewed, different graphs and tables
will be analyzed and interpreted and structure for data base will be developed in this study.
From all the
articles reviewed, it can be concluded that with the right amount of nanoclay mechanical
properties of nanocomposites will be enhanced. Its not only the amount of nanoclay but also the
kind of epoxy used, sample preparation technique, pre and post curing of samples contribute
equally on the mechanical properties of nanocomposites.
Introduction
In the past decade, the research on nanocomposties has shown some promising results.
With the right amount of nano clay, nanocomposites have shown positive result in mechanical
properties. Though the experiments are in primitive stage and yet more to investigate, it is
already heading towards positive direction.
The change in mechanical properties in nanocomposites after filling nano clay has
tremendous impact in the field of material science. This paper will investigate the change in
mechanical properties in nanocomposite after mixing nano particles. Different scientific articles, Bhanu Bhattarai -
Mechanical properties of nanoclay based nanocomposites: a review
journals, and publications will be reviewed, analyzed and interpreted. The study will be limited
to previously published articles, journals and reports.
The possible outcome will be very helpful for the researchers, industries and
academicians, who are working in the field of nanocomposite. Numbers of article will be
reviewed, analyzed and structured in such a way that even novice in the field of nanotechnology
can easily comprehend the report.
Literature Review
In Huang et al. [1], a comprehensive review is presented on the researches and
developments related to electrospun polymer nanofibers including processing, structure and
property characterization, applications, and modeling and simulations. Information of those
polymers together with their processing conditions for electrospinning of ultrafine fibers has
been summarized. Other issues regarding the technology limitations, research challenges, and
future trends are also discussed. In his paper he had concluded that electrospinning is an efficient
technique for the fabrication of polymer nanofibers. Various polymers have been successfully
electrospun into ultrafine fibers in recent years mostly in solvent solution and some in melt form.
In a study conducted at University of Oxford [2], Structural ceramic nanocomposites are
reviewed with emphasis on the Al
2
O
3
/SiC and Si
3
N
4
/SiC systems. The review was divided into
three parts. First, basic processing routes for nanocomposites, namely conventional powder
processing, sol gel processing and polymer pyrolysis and presented in detail. Second, the
mechanical properties of different nanoocomposites are compared. Finally, models which
attempt to explain the improvements in these properties are explored. And it was shown that the
strength increase can best be related to a reduction in processing defect size. Bhanu Bhattarai -
Mechanical properties of nanoclay based nanocomposites: a review
In Ray et al. [3], a wide range of polymer matrices is reviewed, with special emphasis on
biodegradable polymers. In the paper it was concluded that, in general, polymer/layer silicate
nanocomposites are of three different types, namely (1) intercalated nanocomposited, (2)
flocculated nanocomposited, (3) exfoliated nanocomposites. This new family of composites
materials frequently exhibits remarkable improvements of material properties when compared
with the matrix polymers alone or conventional micro and macro composite materials.
Improvements can include a high storage modulus, both in solid and melt state, increased tensile
and flexural properties, a decrease in gas permeability and flammability, increased heat distortion
temperature, and increases in the biodegrability rate of biodegradable polymers, and so forth.
References
[1]
Zheng Ming Huang, Y. Z. Zhang, M.Kotaki and S. Ramakrishna, A review on polymer
nanofibers by electrospinning and their application in nanocomposites, Composites Science and
Technology, Volume 63, Issue 15, November 2003, pages 2223 2253.
[2]
Martin Sternitzke, Structural ceramic nanocomposites, Journal of the European Ceramic
Society, Volume 17, Issue 9, 1997, Pages 1061 1082
[3]
Suprakas Sinha Ray, Masami Okamoto, Polymer/layered silicate nanocomposites: a review
from preparation to processing, Prog.Polym. Sci.28 (2003) 1539 1641
Mechanical properties of nanoclay based nanocomposites
In a research conducted at Tuskegee University, Alabama [4], a novel technique to
fabricate nanocomposite materials was developed. The resin used in this study is a commercially
available SC 15 epoxy (obtained from Applied Poleramic, Inc). It is a low viscosity two phase
toughened epoxy resin system consisting of part A (resin mixture of diglycidylether of bispnol
A (DGEBA), aliphatic diglycidylether epoxy toughener) and part B (hardener mixture of Bhanu Bhattarai -
Mechanical properties of nanoclay based nanocomposites: a review
cycloaliphatic amine and polyoxylalkylamine). The inorganic clay used in this study was K 10
grade montorillonite (obtained from Sigma Aldrich Co.,USA) with a surface area 220 270 m
2
/g.
The weight fraction of clay are range from
0 wt.% to 4 wt.% to identify an optimal loading
giving the best thermal and mechanical properties.
Firstly, clay was dried in oven at a temperature of 80
0
C for 24 hours. Then pre calculated
amount of clay and part A resin were carefully weighted and mixed together in a suitable beaker.
The mixing was carried out through a high intensity ultrasonic irradiation for 1.5 hours with
pulse mode. To avoid a temperature rise during the sonication process, external cooling was
employed by submerging the beaker containing the mixture in an ice bath. Once the irradiation
was completed, part B was added to the modified part A then mixed using high speed
mechanical stirrer for about 10 minutes. A high vacuum was accordingly applied using Brand
Tech Vacuum system for about 30 minutes. After the bubbles were completely removed, the
mixture was transferred into a plastic and Tefloncoated material rectangular molds and kept for
24 hours at room temperature. All as prepared panels ware postcured at 100
0
C for 5 hours in a
Lindberg/Blue Mechanical Convection Oven.
Dynamic Mechanical analysis (DMA), Thermogravimetric analysis (TGA) and three
point bending tests were performed on unfilled, 1 wt.%, 2 wt.%, 3 wt.%, 4 wt.% clay filled SC
15 epoxy to identify the loading effect on thermal and mechanical properties of the composites.
From the DMA and three point bending test, it was observed that the mechanical properties
change with respect to the clay content, however, the TGA results showed that the thermal
stability of composite is insensitive to the clay content. The three point bending test results
indicate that 2 wt.% loading of clay in epoxy showed the highest improvement in flexural Bhanu Bhattarai -
Mechanical properties of nanoclay based nanocomposites: a review
strength as compared to others and likewise, DMA studies also revealed that 2.0 wt.% doped
system exhibit the highest storage modulus which can be seen in the table below.
Material
Modulus
(GPa)
Improvement in
modulus
(%)
Strength
(MPa)
Improvement in
strength
(%)
Neat Epoxy
2.25 ± 0.11
85 ± 4.3
1 wt. % clay
2.58 ± 0.12
14.7
94 ± 5.9
10.6
2 wt. % clay
2.96 ± 0.14
31.6
108 ± 5.6
27.1
3 wt. % clay
2.70 ± 0.14
20.0
105 ± 4.6
23.5
4 wt. % clay
2.43 ± 0.11
8.0
104 ± 4.1
23.5
Table 1: effects of clay content on the mechanical