Flame retardancy properties and thermomechanical behavior of the nanocomposite of thermoplastic Polypropylene/Linear Low-density Polyethylene blend filled with nano calcium carbonate

Abstract

The flammability of thermoplastic polymers, especially of polypropylene, considers one of the crucial global concerns because of the numerous applications of these materials in different aspects of modern life. So, the efforts of scientists are focused on developing the effective flame retardants especially with the progress in the nanotechnology. In this work, Fire retardancy performance, mechanical properties, thermomechanical behavior and thermal stability of the blend of polypropylene (PP) - linear Low density polyethylene (LLDPE) filled with nano calcium carbonate (NCC) were examined. The blend was contained on 90% PP and 10% LLDPE with different loadings of nano calcium carbonate (1.5%, 3%, 6%, 9% of PP weight). The samples were prepared by the extrusion method. The mechanical tests were tensile and bending tests while fire retardancy tests were limited oxygen index (L.O.I), U-94 protocol tests and ash content. The thermomechanical tests were thermal expansion coefficient, and thermal E-modulus. Thermal stability was examined using differential scanning calorimetry (DSC) and Differential Thermal Analysis (DTA). The results of tests showed the positive role of using nano calcium carbonate as filler for this blend. The mechanical properties, thermal expansion coefficient and thermomechanical behaviour were increasing and the highest values were recorded for 6% sample. While the maximum values of thermal stability, and fire resistance properties were recorded for 9% sample. The other nano calcium carbonate addition ratios showed varies responses. The fire retardancy properties were enhanced with using NCC filler. The results of the present work showed the success of using nano calcium carbonate with PP-LLPE blend as a fire retardant.