CHPTAC

CHPTAC, or 3-chloro-2-hydroxypropyltrimethylammonium chloride, is a water-soluble quaternary ammonium salt used as a reactive cationization reagent for polymers and polysaccharides. The molecule contains a quaternary ammonium center with three methyl groups and a 2-hydroxypropyl substituent that ends in a chloride. This chloride is a leaving group that enables nucleophilic substitution by hydroxyl groups on polymers such as cellulose or starch, producing covalent ether linkages.

In typical applications, CHPTAC is used under alkaline conditions to activate hydroxyl sites on cellulose, starch, and related polymers. The reaction installs a 2-hydroxypropyltrimethylammonium group, imparting a permanent positive charge to the material. The resulting cationic derivatives exhibit enhanced affinity for anionic dyes, improved drainage and retention in papermaking, and increased flocculation performance in water treatment. CHPTAC is valued for enabling straightforward post-treatment cationization without the need for harsh reaction conditions.

Handling and safety considerations are important due to the reactive and irritant nature of CHPTAC. It is typically supplied as a solid salt or in aqueous solution and should be handled with appropriate personal protective equipment in a well-ventilated area, following the supplier’s safety data sheet. Storage should be in a cool, dry place away from acids and moisture to minimize unwanted hydrolysis or side reactions. CHPTAC is widely referenced as a reagent for cationizing cellulose and starch in industrial applications.