posted on 2024-01-17, 20:05authored bySensen Han, Qingsong Li, Na Ma, Dongyan Liu, Guoxin Sui, Sherif Araby
In the current study, a facile approach is introduced
to enhance
the flame retardancy of thermoplastic polyurethane (TPU) using a supramolecular-wrapped
α-zirconium phosphate nanohybrid (CPP@ZrP). The CPP@ZrP nanohybrid
was successfully synthesized by enveloping a phytic acid-doped polypyrrole
shell and linking it to cobalt ions via the multivalent anions of
phytic acid. The CPP@ZrP nanohybrid exhibited relatively uniform dispersion
within the TPU matrix, leading to strong interface between TPU and
CPP@ZrP and hence high mechanical and flame-retarding properties.
The strength of TPU increased by 37% with 850% elongation at break
at 5.0 wt % CPP@ZrP. Similarly, adding CPP@ZrP into TPU substantially
reduced the peak heat release rate by 41.8%, peak smoke production
rate by 25.8%, and total CO production by 32.9%. The average effective
heat of combustion from the TPU/CPP@ZrP composite was reduced by 25%
which confirms the reduction in flammable volatile substances. The
experimental measurements and morphology of char residuals reveal
that the CPP@ZrP nanohybrid reduces the flame retardancy of TPU in
the gas and condensed phases via reacting with the flammable volatiles
and preventing heat transfer to the flames. The study introduces a
facile approach to designing a metallic-organic–inorganic hybrid
flame retardant, CPP@ZrP, with high efficacy in reducing fire risks
and mitigating smoke toxicity in polymers.