Comparison of Properties of Anion-Exchange Cottons in Fabric Form

The effects of the substitution of various types of amino groups in cotton on the crease recovery properties have been investigated. The potentiometric titration curves of the various aminized cottons have been used to differentiate the presence of quaternary ammonium groups (strong-base anion exchangers) from the presence of primary, sec ondary, or tertiary amino groups (weak-base anion exchangers). Weak-base anion exchange cottons have been quaternized by treatment of cotton containing tertiary amine groups with methyl iodide and with epichlorohydrin. In addition, strong-base exchangers have been prepared directly by a one-step process in which cotton pretreated with a base is reacted with a mixture of epichlorohydrin and a tertiary amine at a 3: 1 molar ratio. Weak-base aminized cottons containing primary amino groups have been reacted with epichlorohydrin in the presence of an aqueous base to form cottons of improved dry- and high wet-crease resistance. Only those quaternized cottons prepared from the reaction of pure epichlorohydrin on cottons containing tertiary amine groups possessed both high dry- and improved wet-crease recovery properties. Equations are given to illustrate types of reactions investigated and mechanisms of reactions.