Flame retardancy and mechanical properties of thermal plastic composite panels made from Tetra Pak waste and high‐density polyethylene

In this article, flame retardancy thermoplastic composites were developed by extrusion followed by injection molding using recycled Tetra Pak packaging material (TPP) waste and high‐density polyethylene (HDPE) with addition of ammonium polyphosphate (APP) and melamine (MEL) as intumescent flame retardants (FRs). The influences of intumescent FRs on the properties of composites were investigated. FRs loading positively affected flame retardancy, but deteriorated mechanical properties as the loading rate was more than 30 wt%. Considering the fire retardancy and tensile strength (TS), the content of FR should not be more than 30 wt%. When the ratio of APP/MEL was less than 3/1, both combustion behavior and TS of the composites were improved with the increased FR loading, which was supported and verified by the analysis of FTIR spectra and SEM images. The thermogravimetric analysis results indicated that the incorporation APP and/or APP and MEL into composites as FRs into composites promoted char formation and correspondingly improved the thermal stability. The synergistic effect of APP and MEL in the intumescent FR system further improved the flame retardancy of the composites. POLYM. COMPOS., 37:1797–1804, 2016. © 2014 Society of Plastics Engineers