Effects of carbon fibers on the flammability and smoke emission characteristics of halogen-free thermoplastic polyurethane/ammonium polyphosphate

• Published in: Journal of materials science Vol. 51; no. 8; pp. 3762 - 3771
• Main Authors: Zhao, Xiao-long, Chen, Chang-kun, Chen, Xi-lei
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2016; Springer; Springer Nature B.V
• Subjects: Ablation; ammonium polyphosphates; Aromatic compounds; calorimeters; Carbon fiber reinforced plastics; Carbon fibers; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Combustion; Composite materials; Cone calorimeters; Crystallography and Scattering Methods; Emission analysis; Emissions (Pollution); Emissions control; Enthalpy; Flammability; heat; Heat release rate; High temperature; Infrared analysis; Materials Science; Mechanical properties; Original Paper; Polymer Sciences; Polyphosphates; Polyurethane resins; Polyurethanes; scanning electron microscopy; Smoke; Solid Mechanics; spectroscopy; Thermal stability; Thermodynamic properties; Thermogravimetric analysis; thermogravimetry; Thermoplastics; Tobacco smoke; Urethane thermoplastic elastomers; Char Residue; Flame Retardant; Smoke; Heat Release Rate; Limit Oxygen Index
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-015-9694-5

In the present study, the effects of carbon fibers (CFs) on flame retardancy, smoke emission, thermal and mechanical properties of thermoplastic polyurethane (TPU)/ammonium polyphosphate (APP) are investigated. The cone calorimeter results show that the combination of 15.00 wt% APP + 5.00 wt% CF greatly lowered peak heat release rate, total heat release, and total smoke release, as well as increased char residue, which is due to a compact char layer formed on the ablating surface of TPU-4 composites, as shown by the SEM results. Smoke suppression properties investigated by smoke density test demonstrate that CF combined with APP greatly reduced the smoke emission. The TPU composite containing 5.00 wt% CF has the highest LOI value of all the intumescing composites studied. Meanwhile, the addition of CF also caused enhanced mechanical properties of TPU composites to a certain degree. Thermogravimetric (TG) analysis indicates that CF combined with APP enhanced the high-temperature thermal stability of TPU composites compared with the pristine TPU, due to the increase of the char residue. Thermogravimetric analysis/infrared spectrometry (TG–IR) results demonstrate that CF could catalyze the further decomposition of TPU composites and remarkably reduce the production of aromatic compounds as a smoke precursor, which are the major parts of smoke.