In
this article, we report the synthesis of polymer-functionalized
graphene composites as highly potent flame retardants. Functionalized
polyaniline (PANI)- and polypyrrole (PPy)-supported graphene nanocomposites
were synthesized by the reaction of graphene oxide, and monomers of
the above-mentioned polymers, aniline and pyrrole, respectively, in
the presence of phosphoric acid. These synthesized nanocomposites
show excellent flame-retardant properties when coated with cotton
fabric and wood. When G-fPANI and G-fPPy solutions were coated on
a cloth piece which was exposed to a flame its initial shape and size
were sustained by liberating a little amount of smoke. At the initial
stage, the coated cloth did not catch fire for more than 620 s (10.20
min) and 380 s (6.20 min) in case of G-fPANI and G-fPPy, respectively,
whereas the use of only PANI, PPy, and GO coated on blank cloths were
totally burned within 14, 10, and 10 s, respectively. Blank cloth
subjected to fire was totally burned within 10 s, leaving small amounts
of black mass. Flame-retardant efficiency of G-fPANI- and G-fPPy-coated
cloth was confirmed by detailed flame tests such as a limiting oxygen
test (LOI), vertical flammability test, and exposure to high temperature
(∼1500 °C). In the case of the LOI test, G-fPANI- and
G-fPPy-coated cloths show high values up to 47.6 and 41.9 indicating
an excellent flame-retardant property. Like cotton fiber, wood
was also used to check the flame-retardant nature of prepared nanocomposites,
and it showed good results. This is the first time such a novel approach
has been made to prepare polymer-functionalized graphene nanocomposites
as a flame retardant for fire prevention using a simple, cost-effective
route in comparison to prior work.