The Effects of Intumescent Flame Retardant and Nanoclay on Mechanical and Thermal Expansion Properties of High Density Polyethylene Composites

In this work, ammonium polyphosphate and melamine were added as a flame retardant to the nanoclay reinforced high-density polyethylene composites. Ammonium polyphosphate and melamine were added at weight ratios of 0 wt% and 20 wt% to the polymer matrix and their proportions are changed. The addition of nanoclay was carried out at weight ratios of 2 wt% to the polymer matrix. Blending operations were performed by premixing with a mechanical stirrer and melt extrusion technique with twin screw extrusion, respectively. The samples were produced by injection molding. Tensile tests, three-point bend tests, tear tests, the Izod impact tests, and thermomechanical analysis were carried out to investigate the mechanical and thermal expansion properties. Mechanical and thermomechanical test results showed that addition of intumescent flame retardant systems and nanoclay decrease the tensile strength and coefficient of linear thermal expansion values while increasing flexural strengths slightly. However, it has been observed that the addition of additives increases the flexural modulus and density of the polymer composites.