Fabrication of high performance dielectric elastomer blends based on natural rubber, polyethylene, and nano silica

This study investigates the optimization of thermoplastic elastomer blends comprising linear low‐density polyethylene and natural rubber (NR) with nanosilica fillers for electrical insulation applications. We systematically examined several key parameters: the blending method for PE/NR preparation, the mass ratios of PE/NR, types of nano silica, nanosilica loading, and various grades of PE and NR. The properties of PE/NR and PE/NR@nanosilica composites were characterized through tensile testing, dielectric strength measurement, and morphological analysis. Results indicated that PE should be incorporated prior to NR addition, with an optimal mass ratio of 80/20 (PE/NR). The optimum nanosilica content was determined to be 4 wt%, using silica from Merck (silicaM) with high BET surface area. Among the various NR grades and PE types evaluated, the L21/RSS@silicaM formulation exhibited superior performance, achieving a dielectric strength of 100 kV/mm and tensile stress at break of 13.2 MPa. SEM analysis revealed that RSS and SVR3L, which contain higher protein content, demonstrated better nanosilica dispersion within the PE/NR matrix compared to DPNR, which has lower protein content. This enhanced nanosilica dispersion correlates with the improved electrical insulation and mechanical performance observed in the PE/NR@nanosilica blends.