mainly used in electronic wires and cables and hence it is important to improve their
FR activity. Lu et al. [112] prepared EVM rubber composites with expandable graphite (EG) and APP; they noticed effective FR activity and reduced dripping due to
excellent intumescent char formation. Co 3 O 4 nanoparticles were decorated on graphene nano sheets synthesized by a hydrothermal method and were used to prepare
TPU nanocomposites, which exhibited significant improvement in their thermal,
mechanical, FR properties. In such systems, the fire toxicity is reduced drastically.
Because these hybrid nano sheets contain different elements, a catalysis effect (cobalt)
as well as absorption of toxicants (graphene) could be observed [113]. Similarly, a
hyper branched FR was synthesized from N-aminoethyl piparazine and phosphonates; it was subsequently used to prepare PS nanocomposites, which exhibited low
flame toxicity and high FR activity. Hyper branched FRs contain more functional
groups and hence contribute to high FR property improvement [114]. TPU
nanocomposites were prepared by the introduction of g-C 3 N 4 /AHPi into the TPU
structure and the resulting nanocomposite films showed high fire safety [84]. g-C 3 N 4
plays important role here by accelerating the decomposition of AHPi to form char;
further, it promotes the release of free radicals from AHPi. PS nanocomposites were
prepared with g-C 3 N 4 /DAHPi and similar results were observed—a high FR activity
and suppression of pyrolysis gas components compared to neat PS [115]. However,
the PS and TPU systems were not compared with each other for FR activity. The
potential of fire hazards can be reduced with g-C 3 N 4 , but there are some problems,
such as poor dispersion in the polymer matrix and chemical corrosion leading to
partial structural scission of g-C 3 N 4 . To counter such problems, Shi et al. [116]
prepared CPDCPAHPi and CBPODAHPi by esterification and salification and
introduced them into PS to synthesize PS nanocomposites. They observed that the
resultant PS nanocomposites exhibited reduced smoke releasing rate and PHRR;
OAHPi releases non-flammable gases and strengthens the char structure. Cai et al.
[117] prepared TPU nanocomposites with non-covalently modified multi-functional
FR graphene nano sheets and they observed that 4 wt% FGNS showed much
decreased PHRR and THR compared to neat PU because of conjugation between
FGNS and the attached FR. Red phosphorus is also used widely as a FR;
isocyanate-based polyimide (PI) foam nanocomposites have been prepared with red
phosphorus (RP)-hybridized graphene (2.2 wt%). The foams showed a remarkable FR
activity with a high LOI value 39.4%, thermal insulating character, and high
mechanical properties [118]. The development of new methods is necessary to prepare surface-modified GO with various organic and inorganic compounds for FR
polymer nanocomposite preparation.
References
1. X. Wang, L. Wu, J. Li, Synergistic flame retarded poly (methyl methacrylate) by nano-ZrO 2
and triphenylphosphate. J. Therm. Anal. Calorim. 103, 741–746 (2011)
2. M. Lewin, M. Endo, Catalysis of intumescent flame retardancy of polypropylene by metallic
compounds. Polym. Adv. Technol. 14, 3–11 (2003)
102
7 Polymer Nanocomposites for Fire Retardant Applications
FR activity. Lu et al. [112] prepared EVM rubber composites with expandable graphite (EG) and APP; they noticed effective FR activity and reduced dripping due to
excellent intumescent char formation. Co 3 O 4 nanoparticles were decorated on graphene nano sheets synthesized by a hydrothermal method and were used to prepare
TPU nanocomposites, which exhibited significant improvement in their thermal,
mechanical, FR properties. In such systems, the fire toxicity is reduced drastically.
Because these hybrid nano sheets contain different elements, a catalysis effect (cobalt)
as well as absorption of toxicants (graphene) could be observed [113]. Similarly, a
hyper branched FR was synthesized from N-aminoethyl piparazine and phosphonates; it was subsequently used to prepare PS nanocomposites, which exhibited low
flame toxicity and high FR activity. Hyper branched FRs contain more functional
groups and hence contribute to high FR property improvement [114]. TPU
nanocomposites were prepared by the introduction of g-C 3 N 4 /AHPi into the TPU
structure and the resulting nanocomposite films showed high fire safety [84]. g-C 3 N 4
plays important role here by accelerating the decomposition of AHPi to form char;
further, it promotes the release of free radicals from AHPi. PS nanocomposites were
prepared with g-C 3 N 4 /DAHPi and similar results were observed—a high FR activity
and suppression of pyrolysis gas components compared to neat PS [115]. However,
the PS and TPU systems were not compared with each other for FR activity. The
potential of fire hazards can be reduced with g-C 3 N 4 , but there are some problems,
such as poor dispersion in the polymer matrix and chemical corrosion leading to
partial structural scission of g-C 3 N 4 . To counter such problems, Shi et al. [116]
prepared CPDCPAHPi and CBPODAHPi by esterification and salification and
introduced them into PS to synthesize PS nanocomposites. They observed that the
resultant PS nanocomposites exhibited reduced smoke releasing rate and PHRR;
OAHPi releases non-flammable gases and strengthens the char structure. Cai et al.
[117] prepared TPU nanocomposites with non-covalently modified multi-functional
FR graphene nano sheets and they observed that 4 wt% FGNS showed much
decreased PHRR and THR compared to neat PU because of conjugation between
FGNS and the attached FR. Red phosphorus is also used widely as a FR;
isocyanate-based polyimide (PI) foam nanocomposites have been prepared with red
phosphorus (RP)-hybridized graphene (2.2 wt%). The foams showed a remarkable FR
activity with a high LOI value 39.4%, thermal insulating character, and high
mechanical properties [118]. The development of new methods is necessary to prepare surface-modified GO with various organic and inorganic compounds for FR
polymer nanocomposite preparation.
References
1. X. Wang, L. Wu, J. Li, Synergistic flame retarded poly (methyl methacrylate) by nano-ZrO 2
and triphenylphosphate. J. Therm. Anal. Calorim. 103, 741–746 (2011)
2. M. Lewin, M. Endo, Catalysis of intumescent flame retardancy of polypropylene by metallic
compounds. Polym. Adv. Technol. 14, 3–11 (2003)
102
7 Polymer Nanocomposites for Fire Retardant Applications