Thermal Stabilities and Flame Retardancy of Polyamide 66 Prepared by In Situ Loading of Amino-Functionalized Polyphosphazene Microspheres

• Published in: Polymers Vol. 15; no. 1; p. 218
• Main Authors: Lv, Wenyan, Lv, Jun, Zhu, Cunbing, Zhang, Ye, Cheng, Yongli, Zeng, Linghong, Wang, Lu, Liao, Changrong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 31.12.2022; MDPI
• Subjects: Carbon dioxide; Composite materials; Cone calorimeters; Enthalpy; Epoxy resins; Fire hazards; Fireproofing agents; flame retardant; Flame retardants; Fourier transforms; FTIR spectrometers; Heat release rate; Impact strength; Infrared analysis; Infrared instruments; Infrared spectrometers; Mechanical properties; microsphere; Microspheres; PA66; Particulate composites; Phosphazo compounds; Phosphorus; Polyamide resins; Polyamides; Polyethylene terephthalate; Polymer matrix composites; polyphosphazene; Polyphosphazenes; Temperature; thermal stability; Thermogravimetric analysis; Vibration; Water vapor; China; microsphere; thermal stability; polyphosphazene; PA66; flame retardant
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym15010218

The flame-retardant polyamide 66 composites (FR-PA66) were prepared by in situ loading of amino-functionalized polyphosphazene microspheres (HCNP), which were synthesized in the laboratory and confirmed by a Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), and transmission electron microscope (TEM). The thermal stabilities and flame retardancy of FR-PA66 were measured using thermogravimetric analysis (TGA), a thermogravimetric infrared instrument (TG-IR), the limiting oxygen index (LOI), the horizontal and vertical combustion method (UL-94), and a cone calorimeter. The results illustrate that the volatile matter of FR-PA66 mainly contains carbon dioxide, methane , and water vapor under heating, accompanied by the char residue raising to 14.1 wt% at 600 °C and the value of the LOI and UL-94 rating reaching 30% and V-0, respectively. Moreover, the addition of HCNP decreases the peak of the heat release rate (pHRR), total heat release (THR), mass loss (ML), and total smoke release (TSR) of FR-PA66 to 373.7 kW/m , 106.7 MJ/m , 92.5 wt%, and 944.8 m /m , respectively, verifying a significant improvement in the flame retardancy of PA66.