Chemical Name: Polyhexamethylene Guanidine Hydrochloride (PHMG). Molecular Formula: (C8H17N5)n·xHCl, where n = 12–16. CAS No.: 27083-27-8 (EU), 32289-58-0 (USA). Appearance: Colorless to pale yellow liquid, or white powder/crystalline solid. Physical Parameters: Solid content (liquid form) 19.0%–21.0%; pH of 1% aqueous solution 4.0–7.0; density approx. 1.04 g/mL; decomposition temperature ≥ 300°C.
1. Completely soluble in water; miscible with polar solvents such as ethanol and ethylene glycol.
2. Aqueous solutions are colorless and odorless. Toxicological studies indicate low acute oral toxicity (acute oral LD50 in mice > 5000 mg/kg) and no irritation to the skin or eyes [4]. However, inhalation exposure (e.g., in aerosol form) may pose a potential risk of respiratory toxicity.
3. Non-flammable and non-explosive; exhibits excellent stability and non-volatility. It remains stable within a pH range of 1–11, with a shelf life of approximately two years at room temperature.
4. Possesses bactericidal capabilities that are broad-spectrum, highly efficient, and provide long-lasting bacteriostatic effects. Its antimicrobial mechanism is based on the guanidine groups within the polymer, which acquire a positive charge upon dissolution in water. These positively charged groups bind via electrostatic adsorption to the negatively charged cell membranes of microorganisms, thereby inhibiting cell division and leading to microbial death. This mode of action constitutes a physical sterilization process, making the development of microbial resistance unlikely.
5. Non-corrosive to various materials.
6. Non-corrosive in nature.
7. Free from harmful substances such as aldehydes, iodine, and active chlorine.
