Polydadmac, short for poly(diallyldimethylammonium chloride), is a strong cationic, water-soluble polymer commonly used as a coagulant and flocculant. It carries permanent positive charges that effectively neutralize negatively charged particles in water, promoting rapid coagulation and clarification. Polydadmac is widely applied in drinking water treatment, wastewater treatment, sludge dewatering, and papermaking. It is also used as a fixative and retention aid in paper production. Compared with inorganic coagulants, polydadmac works over a wide pH range, produces less sludge, and provides consistent, efficient performance in liquid formulations.