Thermal stability and flame-retardancy mechanism of poly(ethylene terephthalate)/boehmite nanocomposites

• Published in: Polymer degradation and stability Vol. 95; no. 7; pp. 1211 - 1218
• Main Authors: Zhang, Jianjun, Ji, Quan, Zhang, Ping, Xia, Yanzhi, Kong, Qingshan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2010; Elsevier
• Subjects: AlOOH; Applied sciences; Calorimetry; Combustion; Composites; Exact sciences and technology; Flame-retardancy; Forms of application and semi-finished materials; Nanocomposites; Nanomaterials; Nanostructure; PET; Polyethylene terephthalates; Polymer industry, paints, wood; Pyrolysis; Technology of polymers; Thermal degradation; Thermal stability; AlOOH; Nanocomposites; PET; Thermal degradation; Flame-retardancy; Ethylene terephthalate polymer; Ester polymer; Flame retardant; Aluminium Hydroxides oxides; Dispersion reinforced material; Thermal stabilization; Experimental study; Composite material; Thermal stability; Thermal properties; Flammability; Reaction mechanism; Boehmite; Nanocomposite
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2010.04.001

The thermal stability and flame-retardancy properties of poly(ethylene terephthalate)/nano-boehmite composites (PET/AlOOH) were investigated using composites prepared in situ. Combustion behaviour and flammability were assessed using the limiting oxygen index (LOI) and cone calorimetry. The incorporation of nano-boehmite increased the LOI of PET from 18 to greater than 25. Cone calorimetry showed that the heat release rates and total smoke production values of PET/AlOOH composites were significantly less than those of pure PET. It also showed that PET/AlOOH combustion produced greater quantities of char residues than did PET combustion. These results showed that nano-boehmite is an effective flame-retardant for PET. Combustion residues were examined using scanning electron microscopy, indicating that nano-boehmite addition produced consistent, thick char crusts. Thermal stability and pyrolysis were investigated using thermogravimetric analysis and pyrolysis–gas chromatography–mass spectrometry, showing that thermal stability of PET/AlOOH was superior to that of pure PET, fewer cracking products were produced in nanocomposite combustion than in pure PET combustion, and pyrolysis of the flame-retardant polyester was incomplete. We propose a condensed phase mechanism for the PET/AlOOH flame-retardancy effect.