Flammability Properties of Polyvinyl Alcohol Containing New Flame Retardant System

Makhlouf, Ghada; Abdelkhalik, Aksam; Naser, Randa; Hassan, Mohamed

doi:10.21608/ejchem.2021.71259.3568

Flammability Properties of Polyvinyl Alcohol Containing New Flame Retardant System

Document Type : Original Article

Authors

¹ chemical metrology department, national institute of standard

² chemistry department, national institute of standard

³ Reference material laboratory, National Institute of Standards

⁴ Saudi Standards, Metrology and Quality Organization

10.21608/ejchem.2021.71259.3568

Abstract

In this work, graphite (G), ammonium iron (II) sulfate (AFS) and aluminium nitrate were added to polyvinyl alcohol (PVA) at 25% loading level to improve its flame retardancy. In addition, PVA/(G+AFS+AN) composite was prepared. The flammability and smoke density of PVA composites were evaluated by UL94 flame chamber, limiting oxygen index (LOI) and smoke density chamber. Vertical flame spread test (UL94V) indicated that PVA composites achieved V0 class in PVA/(G+AFS+AN)and PVA/AFS samples. Horizontal burning rate (UL94H) data showed that PVA composites achieved H0 class. LOI of PVA was enhanced from 19.1% to 21.3%, 25.2%, 26.1% and 27.2% in PVA/G, PVA/AN, PVA/AFS and PVA/(G+AFS+AN)composites, respectively. The maximum specific optical density (Dsmax) of PVA was decreased in all PVA composites due to the formation of protective char layer on polymer surface. The maximum reduction in Dsmax value of PVA was 64% and it was observed in PVA/(G+AFS+AN). XRD analysis of char residue after smoke density test of PVA/(G+AFS+AN) indicated the presence of coquimbite phase, graphite and magnetite in the char residue. Thermogravimetric analysis (TGA) data of PVA and PVA/(G+AFS+AN) composite showed that the new flame-retardant system improved the thermal stability of neat polymer and the temperatures at which 50% (T50%) weight loss takes place were greatly enhanced. In addition, the char residue at 750 ℃ was increased.

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