| Abstrakt: |
It is shown that the relationship between the improvement in wrinkle recovery and the concentration of a number of wrinkle resistant finishes applied under different con ditions to cellulosic fabrics of different structures and composition is similar to the relationship in the formaldehyde-cotton system. The theory developed for the reaction of formaldehyde with cotton, leading to the conclusion that only a small fraction of the concentration of cross-linking agent required to impart a given improvement in the wrin kle recovery is involved in cross-linking, is shown to be generally applicable to cellulosic reactants. Dialdehydes, diglycidyl ethers, and triazyridinyl phosphine oxide as well as the well known formaldehyde-containing finishes were considered.The relationship between the improvement in wet wrinkle recovery and the concentra tion of agent applied to give the wet wrinkle recovery onlyis similar to the relationship for dry wrinkle recovery improvement and concentration of the reacted finish.The structures and weave of a cotton fabric have little influence on the wrinkle recovery improvement-concentration relationship. Cyanoethylation of cotton makes the hydroxyl groups of cotton less accessible, but the relationship between the improvement in wrinkle recovery and the concentration of reacted cross-linking agent is of the same form as that for unmodified cotton.Chemical modification with a cross-linking agent in the wet swollen state to impart wet but not dry wrinkle recovery does not prevent the subsequent cross-linking to obtain improvement in dry wrinkle recovery; but the tendency to form cross links is reduced. When the physical character of cellulose differs from that in cotton, as in the case of rayon, the difference in the relationship between the wrinkle recovery improvement and the concentration of reacted agent is more profound. Here the constant terms of the theoretical wrinkle recovery improvement-concentration relationship differ in a way which indicates that the tendency of the applied agent to cross-link is less in rayon than in cotton. |
