Effect of Catalyst on the Pore Structure and Performance of Cotton Cellulose Crosslinked with Butanetetracarboxylic Acid

Abstract

Pore structures of cotton crosslinked with butanetetracarboxylic acid (BTCA) and different catalysts were assessed. The catalysts included NaH2PO2.H 2O, Na- H2PO 3.2.5H2O, Na2HPO3.5H2O, NaH2PO4.H2O, Na2HPO4, Na4P2O7, and Na2CO3. Treatments were applied to all-cotton printcloth using a pad-dry-cure process. Textile performance properties were determined for the treated fabrics. Pore size dis tribution was assessed on Wiley milled fabric using a reverse gel permeation chro matographic technique. The water soluble molecular probes employed were sugars and ethylene glycols. Plots were prepared of V, , the accessible internal water, versus the molecular diameters of the probes. In addition, internal structure differences were elucidated by moisture regain, considered to be a measure of the internal surface of the cotton fiber in the conditioned state, and water of imbibition, a measure of internal volume in the water-swollen state. There were definite patterns in textile performance with the different catalysts. The total volume in residual small pores was inversely related to the resilience level achieved, and retained breaking strength was directly related to the volume in residual small pores. Patterns with respect to abrasion resistance were more complex. Because BTCA add-ons were comparable, the data suggest that the more effective catalysts, NaH2PO2 and NaH2PO3, are effecting either a greater number of crosslinks in the cotton or producing crosslinks that differ in actual structure.