Nano-silica as reinforcing filler in NR latex: Role of processing method on filler morphology inside the rubber and properties of the nanocomposite

Abstract

The processing method of a polymer composite plays an important role in determining the filler morphology inside the polymer matrix, which in turn influences the overall properties of the composite. In the present work, colloidal nano-silica was mixed with natural rubber (NR) latex, and the nanocomposites were made by two distinct processes. The first method was simple film casting, which helped to generate a segregated filler network by arranging nano-silica along the outskirts of the rubber latex circles on drying. The second method involved latex co-coagulation with nano-silica, followed by melt mixing in an internal mixer which shattered the segregated network and yielded a random distribution of nano-silica in the NR matrix. The study revealed that irrespective of the processing method and filler morphology, incorporation of nano-silica in NR significantly improved the mechanical and solvent resistance properties in both cases without affecting thermal stability.

Keywords

• rubber
• nanocomposites
• nanosilica
• segregated network
• mechanical properties