All‐In‐One Integration of Inherently Flame‐Retardant, UV‐Resistant, and Antibacterial Polymer by a Biguanide Unit

The increasing fire accidents, excessive UV exposure, and health threats posed by bacterial infections urgently require advanced polymer materials integrating multiple safety protections. In this study, we propose an ultra-efficient strategy to achieve the all-in-one integration of inherently flame-retardant, UV-resistant, and antibacterial polymer materials through a single biguanide unit. The key lies in the unique triple protection mechanism exerted by the biguanide unit: high-temperature char-formation for flame retardance, n→π* transition absorption for UV-resistance, and disruption of the negatively charged bacterial surface for antibacteria. As a result, the biguanide-containing polymer material achieves the best UL-94 V-0 flame-retardant rating with excellent self-extinguishing properties, ≥99.3% ultra-high shielding rate for UV light, and ≥99.0% remarkable antibacterial rate. Importantly, the biguanide unit is chemically bonded to the polymer main chain, which not only avoids the health risks and performance degradation caused by the additive migration, but also exhibits outstanding heat resistance, thermal stability, and easy processability. This work simultaneously achieves triple functional integration of polymer materials through a single biguanide unit, realizing previously unattainable multiple safety protections against dangerous fires, harmful UV, and widely-existed bacteria.