In this study, an N‐alkoxy‐hindered amine‐based UV stabilizing agent (NOR‐116) and nanosized silica particles (Aerosil R‐972) were combined with a cyclic phosphonate based‐flame retardant (FR; PCO‐900) and incorporated into polypropylene via melt extrusion in a microcompounder. In order to stimulate the conditions in the favor of further processing such as fiber spinning, the content of additives in polypropylene was kept low (up to 6.5 wt %). The effects of the PCO‐900, alone and in combination with NOR‐116 and Aerosil‐R972, on the flammability and thermal stability of polypropylene were evaluated by limit oxygen index (LOI) tests, cone calorimetry, and thermogravimetric analysis. The proposed system with 3.5 wt % PCO‐900/1.5 wt % NOR‐116/1 wt % Aerosil‐R972 decreased the heat release, increased the LOI and thermo‐oxidative stability, and, thus, improved the fire resistance of polypropylene. The possible mode of FR activity was also discussed based on the analysis. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48308.

We synthesized a series of chalcone-based polyphosphonates and polyurethanes as self-extinguishing flameretardant polymers and characterized them via FTIR, 1 H, 13 C, 31 P NMR, HRMS, gel permeation chromatography, and inductively coupled plasma−optical emission spectrometry. The thermal stability of the synthesized polymer series was tested by thermogravimetric and evolved gas analysis under both N 2 and air atmospheres as well as microscale combustion calorimetry analysis. After thermal treatment, residue analysis was carried out using scanning electron microscopy with energy-dispersive X-ray analysis and X-ray photoelectron spectroscopy, and decomposition mechanisms are proposed.

The effects of multi-walled carbon nanotubes (MWCNTs) on fire behavior of phosphorus-based flame retardant (PBFR)/polypropylene (PP) were investigated. Two different type phosphorus-based flame retardant that commercially available; ammonium polyphosphate-based (Exolit AP 760) and organic phosphorous-based (Aflammit PCO 900) powders were studied to enhance the flammability of polypropylene. Phosphorus-based flame retardant content was fixed at 8 wt% of total flame retardant (FR) formulation. MWCNTs was incorporated into FR formulation at four different concentrations (0.5 wt%, 1.0 wt%, 1.5 wt% and 2.0 wt%). All composites were prepared by melt compounding in a twin-screw extruder followed by injection molding technique. Thermal properties and flammability of the prepared samples were determined by thermogravimetric analysis (TGA), limiting oxygen index (LOI) and micro combustion calorimetry (MCC). Incorporation of organic phosphorous-based powder into PP matrix showed a better fire performance compared to ammonium polyphosphate-based flame retardant by resulting in an 11.6% higher LOI value. The LOI values decreased with the incorporation of MWCNTs into PP/ PBFR combinations; however, they still increased the thermal stability of each respective system. The addition of 2.0 wt% MWCNTs decreased the LOI value of PP/organic phosphorous-based FR system 5.2% higher than PP/ammonium polyphosphate-based FR system. The heat release rate of PP reduced in the presence of both PBFRs, but; increased with the introduction of MWCNTs.