Mixed Catalyst Systems for Reactions of Cotton with Dimethylolethyleneurea or Dimethyloldihydroxyethyleneurea

Abstract

Substituted acetic acids or dibasic acids in combination with MgCl₂ are active catalyst systems for the reaction between cotton and dimethylolethyleneurea (DMEU) or dimethyloldihydroxyethyteneurea (DMDHEU) at cure temperatures from 105-125°C. The reaction is primarily influenced by hydrogen ion concentration of the pad bath. Based on condi tioned wrinkle recovery of treated facrics, the order of increasing activity among the substituted acetic acid-Mgcl₂ catalyst systems at 115°C in promoting the reaction of cotton with DMDHEU is as follows: acetic ≤ diethylaminoacetic < methylaminoacetic ≤ aminoacetic ≤ thiohydroxyacetic ≤ cyanoacetic ≤ hydroxyacetic acid. The order for the cotton-DMEU reaction is as follows: diethylaminoacetic ≤ acetic ≤ methylaminoacetic ≤ thiohydroxyacetic < hy droxyacetic ≤ aminoacetic ≤ cyanoacetic.

Dibasic acids used with MgCl₂ in the cellulose-DMEU reaction were more effective than either alone in increasing the amounts of bound nitrogen and formaldehyde and the wet recovery angles of the finished cottons. With DMDHEU, only the succinic acid-MgCl₂ combination resulted in an increase in bound nitrogen over that observed with either catalyst used individually. With acids used singly or in combination with MgCl₂, the pH of the pad bath was a primary factor in im proving wrinkle recovery with both DMEU and DMDHEU.