Thermal oxidation stability, electrical properties and flame retardancy of composite material based on HDPE-LLDPE and FA

Abstract

The  composites  of  high-density  polyethylene/linear  low-density  polyethylene (HDPE/LLDPE (75/25  wt/wt) filled by fly ash (FA) with different contents of FA  were prepared by melt mixing in a Haake Rheomixer. The thermal oxidation stability of the composites was evaluated by comparing mechanichal properties before and after heating at 100^oC for 72 hours in an air Memmert oven. Thermogravimetric analysis or TGA was tested in Shimadzu TGA-50H. Their  flammability was tesed in according to UL-94 methods and their electrical  properties (dielectric constant, dielectric loss, electric resistance and breakdown voltage) were investigated in according to standards: ASTM D149, D150, D257, respectively. The results showed that the composites filled with MFA exhibited  some better mechanical properties than those with OFA, the flammability of the  composites  were  improved  with increasing the content of FA. The burning speed of the PE/FA composites were lower than that of the PE matrix. The thermal oxidation stability of the PE/MFA composites was higher than that of the corresponding PE/OFA composites. The dielectric constant and dielectric loss of the PE/FA composites increased and the electric resistance and breakdown voltage decreased with increasing the FA content in PE.