Effect of electron beam radiation on the mechanical, electrical, heat shrinkable and morphological properties of linear low-density polyethylene/polyolefin elastomer blends

Abstract

The blending of polymers is an efficient means for developing new materials in a less hazardous and more economical way compared to the synthetic route. Polymers with different properties are blended to obtain a new material with combined properties. In this study, a thermoplastic elastomer blend is prepared by melt mixing a metallocene-based polyolefin elastomer (Engage 8003, abbreviated as EN) with linear low-density polyethylene (LLDPE, abbreviated as LL) using a twin-screw extruder in various compositions. To investigate the effect of the electron beam on the properties, LL, EN and their blends are irradiated in the 50–250 kGy dose range. The samples are subjected to gel fraction, mechanical, dynamic mechanical, hardness, heat shrinkability, volume resistivity and morphological studies. The % gel fraction, hardness and heat shrinkability of a sample increase with an increase in the irradiation dose. With increasing LL content, Young’s modulus and ultimate tensile strength of the blends are increased, maintaining the % elongation at break in an attractive region. LE64 (60 wt% LL and 40 wt% EN) and LE46 (40 wt% LL and 60 wt% EN) blends show optimized mechanical and dynamic mechanical properties. Irradiation further increases the tensile strength and Young’s modulus of LE64 up to 150 kGy and LE46 up to 200 kGy. The volume resistivity of the LE64 blend increases tenfold and quadruples for LE46 compared to non-irradiated blends when irradiated at 200 kGy. The morphological structures of the non-irradiated and crosslinked blends support the outcome of the obtained properties nicely.