1. Running head: FLAME RETARDANT FOR HOUSEHOLD COUCHES
Flame Retardant for Household Couches:
Coating Foam Inside Couches with a Mixture of Wheat Gluten, Reax 88B and Glycerol to
Prevent Spread of Fire
Douglas Fox, Anh Do
American University – College of Art and Science

2. 2FLAME RETARDANT FOR HOUSEHOLD COUCHES
Abstract
The purpose of this research is to find a cheaper, yet more effective mixture to coat the foam inside
couches with for flame retardant purpose. This research uses wheat gluten and lignosulfonate as
primary flame retardants and focuses on adding other ingredients into the mixture to both maintain
the flame retardant property, minimize the stiffness of the coated foam and prevent wheat gluten
and lignosulfonate from leaving the coated foam. The best mixture contains 80% of wheat gluten,
10% of lignosulfonate, and 10% of glycerol, the chosen plasticizer. A very small amount of tannic
acid is also present to prevent molding. This mixture dries up and forms a flexible film that does
not break easily even when folded up. The foam samples coated with the mixture only experience
a slight increase in stiffness. Only 10% of the total lignosulfonate leaves the sample film after
being soaked in water for one day.

3. 3FLAME RETARDANT FOR HOUSEHOLD COUCHES
Introduction
Research has shown that couches and sofas pose the greatest fire hazard among all the household
furniture. It only takes 1.5 minutes for a non-flame retarded sofa to be burned down and 4.5
minutes for the flame to spread to the entire room. One of the best ways to prevent fire damage
from burning couches from happening is to increase the flame retardant property of the foams or
fillings inside the couches. This research aims at creating a better flame retardant mixture to coat
couch fillings. The mixture must be cheap and easy to make, yet slows down or prevent burning
effectively. After coating, the foam’s softness must not be significantly affected, there must not be
any mold or similar health hazard associating with the coating and the coating mixture must not
easily come off from the foam sample in case water is spilled on the couch.
Previous research has confirmed the excellent fire retardant property of wheat gluten (WG) and
lignosulfonate (Reax 88B). However, coating foam with just WG is inefficient because WG is
hydrophobic, making it unable to fully dissolve in water. After coating and letting the foam sample
dry, the WG forms clumps on the surface and inside the foam sample that do not only come off
the sample easily, but also make the foam significantly harder. On the other hand, Reax 88B
dissolves easily in water. Although this makes it easier to coat foam with Reax 88B, the coating
mixture will likely come off if water is spilled on the sample.
Since the flame retardants mentioned above have properties that can be compensated by one
another, mixing the two chemicals together may produce a better coating mixture. The goal of the
experiments is to find the other ingredients to add into WG and Reax 88B to create a new mixture
that meet all the aforementioned criteria.

4. 4FLAME RETARDANT FOR HOUSEHOLD COUCHES
Materials and Methods
The ingredients and their respective functions
Ingredients Purposes
Wheat Gluten Hydrophobic flame retardant
Water (H2O) Dissolve wheat gluten
Sodium Sulfite (Na2SO3) Make WG grains bond together and form a
coherent structure in water
Ethanol (CH3COOH) Break down WG’s hydrophobic clumps in
solution
Ammonium Hydroxide (NH4OH) Increase dispersion, make WG mixture
dissolve more easily in solution
Sodium Lignosulfonate – Reax 88B Flame retardant
Tannic Acid (C76H52O46) Prevent formation of molds
Glycerol (C3H8O3) Possible Plasticizer
1-Octanol Possible Plasticizer
Polydimethylsiloxane Possible Plasticizer
Table 1: Ingredients in the mixture and their respective functions
Procedure
In all samples, mix a consistent amount of 2.0000 g of WG with 14 ml of H2O and 0.0200 g of
Na2SO3. The mixture is stirred for 10 to 15 minutes, then decanted and washed again with water
to remove excessive Na2SO3.

5. 5FLAME RETARDANT FOR HOUSEHOLD COUCHES
Add 14 ml of NH4OH and 9 ml of Ethanol to the solid. Stir again and heat to 85oC. 0.25 g (10%)
of Reax 88B is then added in, followed by 0.01 g of Tannic Acid.
Add 0.2500 g of plasticizer to the mixture. Each sample only has one plasticizer.
 Preparation to test the solubility of the sample: Put 0.5000 g of the sample into a tube. Pour
in 10 ml of distilled water. Gently disturbed the tubes overnight. Test the solution to see
which chemical dissolves in water.
 Preparation to test the flexibility and flame retardant property of the sample: Pour the final
mixture to a dish and kept to dry in to fume hood. After three to five days, remove the dried
film from the dish.
 Preparation to test the softness and flame retardant property of the coated foam: Coat the
foam with the mixture having the most flexible film by soaking the foam pieces in the
mixture until the weights of the pieces of foam increase to four times. Keep the foam
samples in the fume hood to dry.

6. 6FLAME RETARDANT FOR HOUSEHOLD COUCHES
Results and Discussion
The sample films have similar flame retardant property, with or without plasticizer.
As expected, no molds are formed in any of the samples thanks to the presence of tannic acid.
For all the sample films, about 10% of the Reax 88B put in the mixture dissolves upon soaking in
water. This corresponds to about 1% of the coating mixture. However, Reax 88B has a dark brown
color. When water is spilled on a couch whose filling is coated with this mixture, it is possible that
the cover of the couch will turn brownish yellow. This is undesirable since it directly affects the
aesthetic property of the couch over time. Further research must be conducted to further prevent
Reax 88B from leaving the dried sample mixture.
Without plasticizer, the dried sample was extremely brittle that it was hard to remove it from the
dish without breaking. With 10% of 1-octanol and polydimethylsiloxane (equivalent to 0.2500 g),
the dried sample can be removed from the dish as a whole, but still break upon folding. With 10%
of glycerol, the dried sample was the most flexible, allowing removal as a whole from the dish as
well as folding. The flame retardant property of the films was similar. Under a direct flame, the
films formed good char layers that range from 21.4% to 25.4% (See Appendix A); the films were
caught on fire but the flame was extinguished almost immediately.
The mixture of 80% WG, 10% Reax 88B and 10% Glycerol was chosen for coating. The coated
pieces of foam established very good flame retardant property with 9.3% to 10% of char formation,
reducing the heat release by about 20% (See Appendix A). After drying, the foam hardened
negligibly and there was no visible sign that the coated layer can be removed physically from the
foam samples. Further research should be conducted to increase the flexibility of the sample film
while maintaining the flame retardant property.

7. 7FLAME RETARDANT FOR HOUSEHOLD COUCHES
References
Blomfeldt, Thomas., Johansson, E., Holgate, T., Hedenqvist, M., Nilsson, F., &Xu, J. (2012,
February 14). Thermal Conductivity and Combustion Properties of Wheat Gluten Foams.
ACS Applied Materials & Interfaces (ACS Publications), 4, 1629−1635 Retrieved
December 10, 2015, from http://pubs.acs.org/doi/abs/10.1021/am2017877
Fire Safety. (n.d.). Retrieved December 10, 2015, from http://www.cefic-
efra.com/index.php/furniture-a-textile/fire-safety
Kitabatake, N., Murakami, T., & Tani, F. (2015). Dispersion in the Presence of Acetic Acid or
Ammonia Confers Gliadin-Like Characteristics to the Glutenin in Wheat Gluten. Journal
of Food Science, 80(2), 269-278. Retrieved December 10, 2015, from doi:10.1111/1750-
3841.12757
Pope, Penny M., Sean O'Bannon, and Steven R. Pope (1992). U.S. Patent No. 5,112,533 A.
Washington DC: U.S

8. 8FLAME RETARDANT FOR HOUSEHOLD COUCHES
Appendix A: Flame retardant property of samples and coated foam
Sample THR (kJ/g) HRC
(J/g·K)
Tpeak (°C) char (wt
%)
*THRrel
(kJ/g)
WG film #1 11.7 101 296 / 352 25.1 15.6
WG film #2 12.1 107 351 22.9 15.7
WG film #3 11.2 101 307 / 349 25.4 15.0
WG film #4 12.3 116 354 21.4 15.6
Uncoated foam 25.5 518 286 / 395 0 25.5
Coated foam #1 21.1 397 251 / 424 9.3 23.3
Coated foam #2 21.4 366 292 / 424 10.0 23.8
* - THR relative to amount of material actually consumed = THR / (1 – char fraction)
Table 2: Data and analysis for the samples and coated foam
THR is total heat released. It describes the total amount of fuel added to a fire. HRC is the heat
release capacity. It relates to the maximum heat release rate, or peak temperature of a fire. Char
is produced when some of the material is left unburned. The relative heat released is the heat
released scaled by the amount actually burned. It is related to the heat capacity of the material.
Although the peak heat release rate is often cited as one of the most important factors in a fire,
this actually correlates more closely to the THR in MCC experiments. This is due to the small
size of sample used here.
Figure 1: Heat release rate for the samples and the coated foam
0
20
40
60
80
100
120
140
100 300 500 700
HeatReleaseRate(W/g)
Temperature (°C)
WG #1
WG #2
WG #3
WG #4
0
50
100
150
200
250
300
350
400
100 300 500 700
HeatReleaseRate(W/g)
Temperature (°C)
PUF
PUF + WG
PUF + WG

9. 9FLAME RETARDANT FOR HOUSEHOLD COUCHES
All films produce about the same amount of heat. This is clearer when comparing the relative
total heat released. Only film #3 is different, and its combustion was erratic (greater error in this
data point). Coating polyurethane foam with these formulations reduces both the heat released
and the peak heat released by 20%. The 2nd coating used performed slightly better, as evident by
both the shift in temperature of the earliest event and the reduction in the maximum heat
released. Note that in the foam profiles, the first peak represents depolymerization and
combustion of the isocyanate monomer, while the second peak represents the evaporation and
combustion of the remaining polyol that comprises the polyurethane. This indicates that the
coating reduces the depolymerization (lower peak heat release rate), producing a protective char
that inhibits polyol decomposition (higher temperature of 2nd peak). The first effect is more
significant in these systems and other coatings we have used. The second effect is seen in almost
all of our coatings.