Polyhexamethylene Biguanide, PHMB


Poly hexamethylene biguanide hydrochloride (PHMB) is a new environment-friendly cationic water-soluble polymer. It is a water solution that can be used as a broad-spectrum and high efficiency disinfectant. It is low toxic, steady, non-flammable, non-explosive, and basically non-corrosive to stainless steel, copper, carbon steel, wood, and plastic. Because of its special bactericidal mechanisms, almost all kinds of bacteria shall be killed efficiently and will not develop resistance action.

Polyhexamethylene biguanide hydrochloride is a high molecular polymer, which is easy to be washed away. It is non-corrosive to the skin, and can not be easily absorbed by human organs. Vitro studies show that PHMB is non-toxic to human cells. Skin irritancy test of rabbits and human hands shows that PHMB is non-irritant to animal and human skin.

CAS No.:


Molecular Formula:



Structure Formula:

polyhexamethylene biguanide


AppearanceColorless or light yellow liquidColorless or light yellow liquid
Active Content20% Min.99% Min.
OdorNoneWeak amine odor
pH(1% solution)4.0 Min.4.0 Min.
Density(g/ml, 20℃)1.040~1.050
Absorbance (1%, 236 nm) (1%,236 nm)400 Min.
Absorbance (236/220 nm)1.2-1.61.2~1.6
Moisture0.5% Max.
Water insoluable0.1% Max.
Water solubilityCompleteComplete


Broad spectrum kills and inhibits various types of microbial.

Polyhexamethylene biguanide hydrochloride (PHMB) is odorless and can be easily dissolved in water to form a tasteless colorless transparent solution. It can be used as a disinfectant for almost all kinds of bacteria.

Excellent stability.

PHMB is still kept active after being heated at 280℃ for 15 min.

Non-corrosive to metals.

Polyhexamethylene biguanide hydrochloride is non-corrosive to copper, stainless steel, carbon steel, and other metals.

Sterilization mechanism:

1. The guanidine group in PHMB performs a high activity and the polymer itself is cationic. Since bacteria and viruses are usually anionic, they are easy to be absorbed by Polyhexamethylene biguanide hydrochloride and could not divide and reproduce, and finally turn inactive.

2. PHMB collapses the cell membrane structure and forms transmembrane stomata. Ultimately, it causes cell membrane rupture, disrupts the energy metabolism of the organism, and disables bacteria and viruses.

3. The polymer forms a film that closes off the breathing passages of microorganisms, causing them to suffocate and die.

The sterilization mechanism is independent of the form and type of microorganisms. Even if the microorganisms mutate, the mutation will not affect their efficacy. Microorganisms do not produce resistance to Polyhexamethylene biguanide hydrochloride.

Synthesis of PHMB Antimicrobial:

Adopt the melt polycondensation method. Put the appropriate amount of guanidine hydrochloride and 1, 6-hexane-diamine in the polymerization kettle, stir, and raise the temperature.

After the reactants are completely melted, continue to raise the temperature, constant temperature reaction for about 2h. And then raise the temperature to a predetermined temperature for the reaction.

After the reaction is finished, stop stirring, and pass nitrogen gas into the kettle. Open the discharge port at the same time. Let the product flow into the pre-prepared container. Let it cool down and solidify, then crush it for use.

synthesis reaction formula of alkylbiguanide

Synthesis reaction formula of alkyl-biguanide

By following the above procedure, theoretically, a bulk polymer can be produced. But in practice, due to the difference in the reactivity of the functional groups, will produce an insoluble cross-linked structure, cross-linked polymers are insoluble, and not conducive to melt processing, but as long as the appropriate reaction conditions can be controlled to obtain linear high molecular weight products.


Polyhexamethylene biguanide hydrochloride can completely kill escherichia coli, staphylococcus aureus, candida Albicans, gonococcus, salmonella, pseudomonas aeruginosa, listeria, dysentery, aspergillus niger, brucella, vibrio parahaemolyticus, vibrio algolyticus, vibrio eelis, Aeromonas hydrophilus, sulfate-reducing bacteria, iron bacteria, and saprophytic bacteria. It is suitable to care solutions for contact lenses, cosmetics, medical, pharmaceuticals, skin, mucosa, vegetable, fruit, air, drinking water, swimming pool, paper making, tissue, anitary pads, clothes, etc.

Polyhexamethylene biguanide hydrochloride can be widely used in textile, animal husbandry, aquaculture, medical sterilization, and daily disinfectant.


PHMB is usually formulated with other water treatment chemicals. The exact formula depends on water and equipment conditions. The recommended dosage is 100~500 mg/L when used as a separate disinfectant. The dosage should be determined by the exact process and method if applied in textile and printing, livestock-raising, and aquaculture.

Packing and Storage:

Store in a cool, dry, well-ventilated warehouse. Keep away from fire and heat sources. Protect from direct sunlight. The package must be sealed and not get wet. It should be stored separately from oxidizers, and flammable and combustible materials.


biguanide phmb; polyhexamethylene biguanidine; polihexanide; polyhexanide hydrochloride.