The lightweight and eco-friendly idea came up with new concept of using fly ash as filler in polymer composites because of their low density, good dispersion, globular particles fluidity, enhanced strength, and economical perspective. The infrastructures of industries, residential buildings as well as constructional materials, and materials used in different sectors in different ways worldwide demanding satisfaction with lightweight and eco-friendly materials having good physical properties, mechanical properties such as Compressive strength, Flexural strength, Impact Strength, Tensile strength, etc. and chemical properties via Fourier-Transform infrared spectroscopy (FTIR), Scanning electron microscopic (SEM), Thermal gravimetric analysis (TGA), etc. To get better properties numerous on going researches are going on to develop new materials which would be lightweight and eco-friendly. In the same way composites became more captivating materials and encountering with the traditionally available clay/ceramic materials and their conventional counterparts due to many compelling advantages.

1. A Presentation
On
Fly ash mediated epoxy composites: A Review
Presented by
VIGYAN NIDHI
M.Tech (Environmental Science and Engineering)
Under the Supervision of
Dr. Deepesh Singh
Assistant Professor (Civil Engineering Dept.)
&
Dr. G.L. Devnani
Assistant Professor (Chemical Engineering Dept.)
HBTU, Kanpur (Uttar Pradesh).

2. Content
• Introduction
• Materials
• Surface treatment/modification
• Physical method of modification
• Chemical method of modification
• Composite behaviour
• Conclusion
• References

3. Introduction
• Increasing infrastructures demanding satisfaction with lightweight and
eco-friendly materials having good physical & mechanical properties.
• Lightweight and eco-friendly concept came up with fly ash as filler in
polymer composites because of their density, good dispersion and
fluidity of globular particles.[8]
• In April 2018-September 2018, in India alone, thermal power stations
produced 93.26million tons fly ash and utilization is 64.08million tons
– reported by “Central Electrical Authority” New Delhi.
• Though, fly ash can be used to make composites to maximize the fly
ash consumption and safe management.
• Polymer composites are the novel material which can utilize fly ash as
a potential material as filler in manufacturing of composites for diverse
applications.[9]

4. Table1. Some fly ash / Epoxy composites studied for different characteristics.
S.
No.
Composite Filler/reinforcement Characteristics Reference
1. Epoxy MSWI Fly ash Tensile property &
leaching behavior
Goh et al.[10]
2. Epoxy Fly ash with sisal fibers. Tensile Strength &
Density
Pappu and
Thakur,[11]
3. Epoxy Fly ash Tensile, flexure
strength, and Impact
behavior
Pattanaik et
al.[12].
4. Epoxy Fly ash & Silica fumes Tensile & Compressive
Strength
Ravishankar et
al.[13]
5. Epoxy Fly ash & Glass fiber Compressive strength. Kulkarni and
Kishore [14]
6. Epoxy Fly ash Flexure property Dharmalingam
et al.[15]
7. Epoxy Fly ash Tensile & Impact
Strength
Shubham and
Tiwari. [16]
8. Epoxy Fly ash Hardness, Impact
strength
Raja et al.[17]

5. Materials
• Fly ash:
By-product of power and incineration plants
Density :1.97-2.89 g/cc
Size: Generally ranges 10-100micron.
 Spherical-specific surface area: 4000-10,000
cm2/g.
Hydrophilic nature

6.  Mineral composition: SiO2 > Al2O3 > Fe2O3 > CaO > K2O >
MgO, Na2O, TiO2.[18]
 Toxic constituents: Arsenic, boron, cadmium, chromium, lead,
lithium, mercury, selenium, thallium and uranium.[3][4]
Figure 1.(a)&(b): Fly ash beside the road, Panki thermal power station, Kanpur, Uttar
pradesh.
(a) (b)

7. • Epoxy:
Thermosetting polymer.
Hydrophobic nature.
Good adhesion, mechanical properties, low
moisture content, little shrinkage, and easy to
process.[7]
Cure within 24-48 hours at ambient
temperature mixed with hardener.[12]

8. Surface treatment/modification
• The composites of polymeric material (Hydrophobic nature)
and Fly ash particles (Hydrophilic nature) are irreconcilable,
leading poor interfacial bonding and lower mechanical
properties.[19]
Fig. 2. Schematic presentation: (a) between epoxy matrix and
unmodified Fly ash and (b) of interphase between epoxy matrix grid and
modified fly ash particles[5]
(a) (b)

9. • Two methods:
1. Physical treatment/modification
2. Chemical treatment/modification
• Another modification method- Pulverized fly ash
particle up to micro and nano size.[15]
• The surface modification of fly ash promotes the
dispersion and crosslink in organic matrix.[21]
• Surface treated fly ash with surfactant avoids particle-
particle interaction between fly ash particulates,
enhances physical properties. Hydroxyl group of fly ash
surfaces causes agglomeration of fly ash particles due
to strong filler-filler interaction in epoxy matrix.[10]

10. Physical method of modification
• Colloidal mesoporous silica (CMS)
• Nanoparticle.
• Entraps the fly ash particle.
• Used as physical method of treatment for fly
ash surface to avoid agglomeration of fly ash
particles due to strong filler-filler interaction.
• CMS enhance the dispersion of fly ash in
epoxy matrix [22]

11. Chemical method of modification
• Coupling agents or surfactants are chemical treatment
method .
• Fly ash with silanes (Coupling agent) or surfactants are
capable to convert mineral of inorganic particulate filler into
materials bearing covalently bound functional groups and
improve the mechanical properties of composite.
• Surfactant sodium lauryl sulphate. [15]
• Coupling agents:- Bis(3-triethoxy silyl) propyl tetrasulfide (Si-
69), gamma-aminopropyl triethoxy silane, Glycidoxy propyl
trimethoxy silane(GPTMS) etc.

12. • For example, surface treatment mechanism of fly ash using coupling
agent (Bis(3-triethoxy silyl) propyl tetrasulfide) is shown in figure 4.
• Bis(3-triethoxy silyl) propyl tetrasulfide, which accordingly stated
that, a single molecule of Si-69 can couple with one alkene unit of
elastomer molecule and also two –OH group of fly ash, resulting in
an increased elastomer-filler interaction[19],[20]
Fig. 4. Reaction involved in modification of fly ash with Si-69. [20].

13. Fig. 5. Chemical reaction between Si69-treated Fly ash and Natural rubber.[19]

14. Fig.6. Si-69 modified fly ash bonding with polybutadiene rubber. [19]

15. Fig.7. A model of the treated fly ash/epoxy composites using N-
2(Aminoethyl)-3 aminopropyltrimethoxysilane (KBM-603), concentration 0.5
wt% of the fly ash.

16. Composite Behaviour
Fig.8. Comparison in flexure strength among unmodified, silanized, and CMS-
Treated fly ash/ epoxy composite. [10]

17. Fig.9. Comparison in Tensile strength among unmodified, silanized, and CMS-
Treated fly ash/ epoxy composite. [10]

18. Fig. 10. Comparable tensile strength of fly ash reinforced epoxy composites in
different curing condition. [12]

19. Fig. 10. Comparable flexure strength of fly ash reinforced epoxy composites in
different curing condition. [12]

20. Fig. 11. Impact strength of surface treated fly ash filled modified epoxy composites.[15]
MIC=Epoxy composite with unmodified fly ash.
SUM= Sub micron -size reduced fly ash
SI= Glycidoxypropyl trimethoxysilane (GPTS) treated fly ash
SLS= Sodium lauryl sulphate treated fly ash

21. Fig. 12. Compressive strength of sieved fly ash/epoxy composite[6]

22. Conclusion
• Fly ash can be used to make composites to maximize the fly
ash consumption and safe management.
• Fly ash mediated epoxy composites have great potential to
use them as a new material due to its non-corrosive
property, lower density and better mechanical properties.
• It is also a new way to reduce and reuse fly ash making eco-
friendly material.
• Due to better physical and mechanical property composite
can be used to make tiles, bricks, window and door frames,
may help to reduce dead load of buildings.
• But, economically accessibility may be a major concern,
which needs leads for some more research.

23. References
1. Dhadse, S., Kumari, P., & Bhagia, L. J. (2008). Fly ash characterization, utilization and
Government initiatives in India ŒA review
2. Ahmad, I., & Mahanwar, P. A. (2010). Mechanical properties of fly ash filled high density
polyethylene. Journal of minerals and materials characterization and engineering, 9(03),
183.[2]
3. Lockwood, Alan H.; Evans, Lisa. "How Breathing Coal Ash Is Hazardous To Your
Health" (PDF). Physicians for Social Responsibility. Retrieved 3 March 2016.[3]
4. Steven G.; Evans, Lisa Gollin. "Coal Ash The toxic threat to our health and
environment"(PDF). Physicians for Social Responsibility. Retrieved 3 March 2016[4]
5. Stimoniaris, A., Skoura, E., Gournis, D., Karakassides, M. A., & Delides, C. (2019). Structure
and Properties of Epoxy/Fly Ash System: Influence of Filler Content and Surface
Modification. Journal of Materials Engineering and Performance, 28(8), 4620-4629.[5]
6. Sim, J., Kang, Y., Kim, B. J., Park, Y. H., & Lee, Y. C. (2020). Preparation of Fly Ash/Epoxy
Composites and Its Effects on Mechanical Properties. Polymers, 12(1), 79.[6]
7. Faruk, O., Bledzki, A. K., Fink, H. P., & Sain, M. (2012). Biocomposites reinforced with natural
fibers: 2000–2010. Progress in polymer science, 37(11), 1552-1596.
8. Yang, Y. F., Gai, G. S., Cai, Z. F., & Chen, Q. R. (2006). Surface modification of purified fly ash
and application in polymer. Journal of Hazardous Materials, 133(1-3), 276-282.
9. Saxena, M., Morchhale, R. K., Asokan, P., & Prasad, B. K. (2008). Plant fiber—industrial waste
reinforced polymer composites as a potential wood substitute material. Journal of composite
materials, 42(4), 367-384.
10. Goh, C. K., Valavan, S. E., Low, T. K., & Tang, L. H. (2016). Effects of different surface
modification and contents on municipal solid waste incineration fly ash/epoxy composites.
Waste management, 58, 309-315.

24. 11. Pappu, A., & Thakur, V. K. (2017). Towards sustainable micro and nano composites from
fly ash and natural fibers for multifunctional applications. Vacuum, 146, 375-385.
12. Pattanaik, A., Mukherjee, M., & Mishra, S. B. (2019). Influence of curing condition on
thermo-mechanical properties of fly ash reinforced epoxy composite. Composites Part B:
Engineering, 176, 107301.
13. Ravishankar, K. S., & Kulkarni, S. M. (2017, August). Synthesis and comparison of
mechanical behavior of fly ash-epoxy and silica fumes-epoxy composite. In IOP Conference
Series: Materials Science and Engineering (Vol. 225, No. 1, p. 012299). IOP Publishing.
14. Kulkarni, S. M. "Effect of filler–fiber interactions on compressive strength of fly ash and
short‐fiber epoxy composites." Journal of applied polymer science 87, no. 5 (2003): 836-841.
15. Dharmalingam, U., Dhanasekaran, M., Balasubramanian, K., & Kandasamy, R. (2015).
Surface treated fly ash filled modified epoxy composites. Polímeros, 25(6), 540-546.
16. Shubham, P., & Tiwari, S. K. (2013). Effect of fly ash concentration and its surface
modification on fiber reinforced epoxy composite′ s mechanical properties. IJSER, 4, 1173-
1180.
17. Raja, R. S., Manisekar, K., & Manikandan, V. (2013). Effect of fly ash filler size on
mechanical properties of polymer matrix composites. International journal of mining,
metallurgy and mechanical engineering, 1, 2320-4060.

25. 18. Blissett, R. S., & Rowson, N. A. (2012). A review of the multi-component utilisation of coal
fly ash. Fuel, 97, 1-23.
19. Alkadasi, N. A., Hundiwale, D. G., & Kapadi, U. R. (2004). Effect of coupling agent on the
mechanical properties of fly ash–filled polybutadiene rubber. Journal of Applied Polymer
Science, 91(2), 1322-1328.
20. Thongsang, S., & Sombatsompop, N. (2006). Effect of NaOH and Si69 treatments on the
properties of fly ash/natural rubber composites. Polymer composites, 27(1), 30-40.
21. Parvaiz, M. R., Mohanty, S., Nayak, S. K., & Mahanwar, P. A. (2011). Effect of surface
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26. THANK YOU