Vapor Phase Sorption of Formaldehyde on Cotton and Its Role in Formaldehyde Release from Durable Press Cotton

Abstract

The low concentrations of formaldehyde found in the vicinity of durable press fabrics are due to the high affinity of formaldehyde for cellulosic substrates. Transport of formaldehyde that is generated by hydrolysis of the finish to the atmosphere is controlled by a sorption equilibrium that increasingly favors the cellulosic substrate with decrease in temperature, and the high distribution coefficient at ambient temperatures minimizes the exposure risk. Sorption isotherms follow the Langmuir equation, suggesting site sorption. The high heat of sorption indicates chemical rather than physical sorption and suggests that hemiacetal formation is involved. At temperatures above 65°C, hemiacetals react further to form methylene crosslinks, which are hydrolytically very stable and from which formaldehyde is not recovered by simple extraction with water at 60°C.