Relative Reactivities of Cotton Celluloses: Formylation

Abstract

Autocatalytic formylation with 90% formic acid at 30° C has been employed as a means of assessing the chemical reactivities of cotton celluloses in a variety of physical and chemical modifications. The reaction is reproducible and sensitive to small changes in physical or chemical modification of cotton. By comparing relative degrees of formylation at a selected reaction period (16-hr), relative reactivities are measured and assigned to cotton celluloses. Significant differences in relative reactivities are found with different lots of cotton, degrees of purification, physical state, tension, mercerilation, amine treatments, and modification by various cross-linking agents, the directions of effects being consistent with those indicated by moisture regain, dye absorption, crystal linity by acid hydrolysis and crystallinity by X-ray diffraction. Relative reactivities obtained via formylation are discussed, together with the relationship between formylation and acetylation.