Facile Synthesis of Intrinsic Antimicrobial Silicone Rubber via Covalent Grafting and Its Properties

ABSTRACT Room temperature vulcanized (RTV) silicone rubber, often used in humid environments, is susceptible to microbial degradation, leading to performance and aesthetic deterioration. To address this, this study developed an intrinsic antimicrobial RTV silicone rubber (SR/QAS) by blending a quaternary ammonium salt (QAS) antimicrobial agent, dimethyloctadecyl[3‐(trimethoxysilyl)propyl]ammonium chloride (DC5700), into its cross‐linking structure through covalent bonding. The effects of DC5700 on the cross‐linking mechanism, mechanical properties, thermal property, and surface wettability of silicone rubber were systematically investigated. The addition of DC5700 significantly reduced the tack‐free time due to the hydrophilic QAS groups accelerating the curing process. Cross‐linking density initially increases and then decreases with increasing DC5700 content. This trend is reflected in the mechanical properties, where the tensile strength and elongation at break attain their peak values at a concentration of 3% DC5700. SR/QAS also exhibits better thermal stability than the base silicone rubber due to the enhanced cross‐linking density. In summary, this study presents a straightforward approach to prepare intrinsic antimicrobial silicone rubber, which minimizes the risk of antimicrobial agent leakage. The findings offer valuable insights for the development and application of similar materials across diverse fields.