Synergistic effect between carbon nanoparticle and intumescent flame retardant on flammability and smoke suppression of copolymer thermoplastic polyurethane
Copolymer thermoplastic polyurethane (C-TPU) was extruded with intumescing flame-retardant formulations based on ammonium polyphosphate and macromolecular nitrogen phosphorus. Carbon nanofiber and carbon nanotube were used as the additional carbon source. The synergism effect of each additive and their intumescing combinations on C-TPU composites degradation, smoke suppression, flammability, and melt rheology was systematically investigated by thermogravimetric (TG), smoke density test and cone calorimeter test (CCT), etc. The TG results showed that carbon particles combined with IFR showed a notable improvement in thermostability at high temperature, and this intumescing flame-retardant system effectively catalyzed the decomposition of macromolecule volatiles that is the major source of smoke particles. This intumescing flame-retardant system also promoted the generation of compact and continual char layer, reduced the peak heat release rate by more than 80% and the smoke generation by 50% obtained from CCT. What is more, the scanning electron microscopy (SEM) showed that this flame-retardant system could promote the formation of a char layer with network structure which helps produce composites with superior flame retardant. A synergistic effect on enhancing the limit oxygen index (LOI) and restricting the dropping of the composites is also obtained. This study has a potential contribution to the development of carbon-based flame-retardant composites.
This study is financially supported by the National Natural Science Foundation of China (NSFC) through Grants 51576212, 51534008, and 51622403, and the National Key Research and Development Project of China through Grants 2016YFC0802501. The authors appreciate the supports deeply.
Compliance with ethical standards
Conflict of interest
All authors declare that they have no conflict of interest.
- 1.Wang X, Kalali EN, Wan J-T et al (2017) Carbon-family materials for flame retardant polymeric materials. Prog Polym Sci 69:22–46. https://doi.org/10.1016/j.progpolymsci.2017.02.001 CrossRefGoogle Scholar
- 3.Zhang QJ, Zhan J, Zhou KQ et al (2015) The influence of carbon nanotubes on the combustion toxicity of PP/intumescent flame retardant composites. Polym Degrad Stab 115:38–44. https://doi.org/10.1016/j.polymdegradstab.2015.02.010 CrossRefGoogle Scholar
- 5.Yuan BH, Fan A, Yang M et al (2017) The effects of graphene on the flammability and fire behavior of intumescent flame retardant polypropylene composites at different flame scenarios. Polym Degrad Stab 143:42–56. https://doi.org/10.1016/j.polymdegradstab.2017.06.015 CrossRefGoogle Scholar
- 19.Wang X, Song L, Pornwannchai W et al (2013) The effect of graphene presence in flame retarded epoxy resin matrix on the mechanical and flammability properties of glass fiber-reinforced composites. Compos Part A Appl Sci Manuf 53:88–96. https://doi.org/10.1016/j.compositesa.2013.05.017 CrossRefGoogle Scholar
- 21.Du BX, Fang ZP (2011) Effects of carbon nanotubes on the thermal stability and flame retardancy of intumescent flame-retarded polypropylene. Polym Degrad Stab 96:1725–1731. https://doi.org/10.1016/j.polymdegradstab.2011.08.002 CrossRefGoogle Scholar
- 24.Zhu HF, Zhu QL, Li J et al (2011) Synergistic effect between expandable graphite and ammonium polyphosphate on flame retarded polylactide. Polym Degrad Stab 96:183–189. https://doi.org/10.1016/j.polymdegradstab.2010.11.017 CrossRefGoogle Scholar