Chemical and Physical Properties of Cotton Modified by N-Methylol Agents

Abstract

Reaction mechanisms for conventional chemical finishing treatments for cotton and hydrolysis of these finishes involving acetals, aldehydes, or N-methylol finishing agents are similar in that the rate-determining step involves the formation of a res onance-stabilized intermediate ion. A study of these mechanisms suggests that in acetal or aldehyde type reactions, cellulose by virtue of its chemical structure can have an influence, often predictable, on reaction paths and rates. On the basis of the concepts developed, the study suggests that acetal crosslinking agents in an optimized, conventional pad-dry-cure process must primarily involve either reactive acetals that act as donors of an appropriate aldehyde, e.g., formaldehyde, or less reactive acetals that must be applied under relatively strong reaction conditions. A similar prediction is made concerning crosslinking of cellulose with aldehydes; however, each aldehyde must be considered on its own because of the many factors involved. The theory behind these predictions is examined in detail and the importance of the chemical structure of the reactant and intermediates is stressed.