Polyethylenimine

Polyethylenimine (CAS 9002-98-6), commonly abbreviated as PEI, is a high-density amine polymer available in both branched and linear forms. Known in some industrial contexts as Montrek 1000, it functions as a cationic flocculant and surface modifier. It also acts as an adhesion promoter across a broad range of industrial processes. In water treatment, PEI acts as a coagulant and flocculant, binding suspended solids, heavy metals, and anionic contaminants for efficient removal.

Textile and paper manufacturers apply it as a wet-strength agent and fiber retention aid, improving process yields and end-product durability. In coatings and adhesives, PEI serves as a primer layer or crosslinking agent. This enhances substrate adhesion on films, foils, and packaging laminates. Industrial cleaning formulations incorporate it for its chelating capacity, sequestering metal ions that would otherwise reduce detergent performance.

PEI is supplied as aqueous solutions, with concentration levels commonly ranging from 30% to 50%, and in solid form for specialized applications. Molecular weight variants are standard across the market. These range from low-MW grades suited to surface treatments to high-MW grades for flocculation. Technical and industrial grades are the most commercially prevalent for various manufacturing requirements.

Specific grades are available to meet water treatment and coating application requirements. The polymer remains a versatile chemical intermediate for diverse global industrial sectors and specialized chemical processing.