Influence of the Incorporation Method of Aluminosilicate Cenospheres on the Structure and Properties of Butyl Rubber-Based Composites

This study investigates the influence of aluminosilicate cenosphere incorporation methods—solution mixing and mechanical mixing via rolling—on the structure and properties of butyl rubber-based composites. Two cenosphere fractions were used, with average particle sizes of approximately 70 µm and 100 µm. A comprehensive analysis was conducted, including scanning electron microscopy (SEM), optical microscopy, density measurements, thermogravimetric analysis (TGA), swelling resistance in gasoline, and mechanical testing. The results demonstrated that both the dispersion quality and the structural integrity of cenospheres strongly depend on the mixing technique and filler size. Composites prepared via solution mixing showed more uniform cenosphere distribution and better preservation of particle morphology. The 70 µm cenospheres, characterized by lower bulk density and higher specific surface area, enhanced the barrier properties and reduced swelling in aggressive media. However, the mechanical strength of the composites decreased with increasing cenosphere content, particularly at high loadings. These findings highlight the critical role of filler morphology and processing method in tailoring the performance of rubber-based composite materials.