| The flame-retardant effect of Poly (Pentabromobenzyl Acrylate), FR-1025, and antimony oxide, AO, on Poly (Hexamethylene Adipamide), Nylon 66, was studied using pyrolysis-chemical ionization mass spectrometry (PY-CI-MS), limiting oxygen index (LOI), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Pyrolysis was carried out directly in the ion source of a double focussing, magnetic sector mass spectrometer operating in chemical ionization mode by using a high temperature pyrolysis (HTP) probe. Pyrolysis of Nylon 66 at 1400{dollar}spcirc{dollar}C containing differing concentrations of flame retardant/antimony oxide in the mole ratio of 1:0, 2:1 and 3:1 suggested that the additives interacted with Nylon 66 in the gas phase to impart flame retardancy. Condensed phase interaction was also indicated by the TGA results. The LOI values confirmed that the mole ratio 3:1 is more effective than 2:1 for flame retardancy. The DSC data suggested that there was no interaction between the additives and the Nylon 66 until 300{dollar}spcirc{dollar}C. |
