Preparation of Insulating Materials based on Natural Rubber/Polyethylene blend and nanosilica ☆

In this study, a polyethylene/natural rubber (NR) blend was explored by determining the optimal content of natural rubber with polyethylene, selecting the type of rubber and nanosilica filler, and identifying the appropriate blend preparation conditions. The mechanical strength, electrical performance, and morphological characteristics of these blends were evaluated. Differences in these properties were linked to the choice of materials and the development of a suitable blend preparation process. Three types of rubber were investigated for blend preparation, including SVR3L and RSS from Vietnam, as well as deproteinized rubber derived from high-ammonia natural rubber (HANR) prepared from Vietnam high ammonia commercial latex (HA latex). To further enhance the material properties, several types of silica fillers were introduced, including silica from Merck and Tokusil 255G silica from Thailand. The addition of nanosilica, when properly dispersed, resulted in significant improvements in both mechanical strength and electrical properties. The PE and RSS-based blend with Merck nanosilica exhibited the highest mechanical and electrical strength. The PE/NR blend containing nanosilica, prepared by melt mixing, showed that incorporating silica into the rubber before blending with PE resulted in higher mechanical strength compared to adding silica into PE before blending with rubber. The morphological analysis demonstrated the successful development of a nanocomposite material based on natural rubber, polyethylene, and nanosilica.