The effect of boron nitride, carbon nanotubes, and theirsynergy on the properties of LLDPE and LLDPE/wax blend

Abstract

This study deals with the effect of two types of conductive fillers (viz., boron nitride and single walled carbon nanotubes) on the properties of the linear low-density polyethylene (LLDPE) matrix and LLDPE/paraffin wax (PW) blend. Pure LLDPE and paraffin wax/LLDPE blend (30/70) were melt-mixed with 2 wt% content of boron nitride (BN) and single walled carbon nanotube (SWCNT), as well as their synergy at 2 wt%. Because it is well known that both conductive fillers were able to improve the thermal conductivity of the paraffin wax/polymer blends, the aim of this study was to focus on the effect of both conductive fillers on the dispersion of paraffin wax into LLDPE matrix, mechanical properties, crystallization behavior, and thermal stability of the LLDPE/wax blend. Scanning electron microscopy (SEM) images of the LLDPE/paraffin wax blends depicted a phase separated system, which was further supported by two separate peaks from the differential scanning calorimetry (DSC). The morphology of the system showed that the addition of boron nitride (BN) into the LLDPE/paraffin wax blend had no affinity with the paraffin wax, while the addition of single walled carbon nanotubes (SWCNT) showed better dispersion into the LLDPE/paraffin wax/BN blend composites. The incorporation of the SWCNT and its synergy with BN enhanced the thermal stability of the LLDPE.