Effect of Titanium Dioxide on Cure Characteristics and Physico Mechanical Properties of High-Temperature Vulcanizing Silicone Rubber Composites

Silicone rubber (SiR), a vital elastomer, is extensively used in producing various engineering and general products, owing to its distinctive properties. Despite the remarkable properties, SiR-based products require anti-microbial agents such as titanium dioxide, TiO2 to negate black mold issues. Still, adding this agent alters the composites' processability and physical and mechanical properties. This study examined the impact of adding different TiO2 content as fillers on silicone rubber composites' processability, physical properties, and mechanical properties. Raw materials of 20-hardness high-temperature-vulcanization (HTV) SiR- reinforced with various TiO2 contents at 0.0, 0.3, 0.6 and 1.2 wt% were prepared using a two-roll mill. The results indicated SiR composites reinforced with 0.3 wt% TiO2 exhibited the best performance with a tensile strength of 1.49 MPa, elongation at break of 340.87%, modulus 100% of 0.664 MPa, modulus 300% of 0.822 MPa, and modulus 500% of 0.954 MPa. This performance can be attributed to the efficient crosslink density and the effective interactions between the TiO2 and silicone rubber particles at this concentration. Structural and morphological analyses further corroborated the results. Consequently, it can be inferred that silicone rubber reinforced with 0.3 wt% titanium dioxide holds the potential for formulating silicone rubber compounds that necessitate anti-microbial properties.