The cellulose–butadiene diepoxide reaction and its effect on the crease resistance of cotton

Abstract

Butadiene diepoxide (BDE), the meso‐1,2,3,4‐diepoxybutane, may be added to cotton cellulose with a variety of catalysts and conditions at room temperature. A slow addition of BDE from nonpolar solvents to yarns pretreated with alkali resulted in weight gains which were proportional to the activity of hydroxyl ions used in pretreatment. For a given hydroxyl ion activity, percentage weight gains of BDE varied directly with time of reaction. Add‐on of BDE has been shown to be proportional to the product of hydrolyzed BDE and molarity of the hydroxyl ion in the dilute alkali. It has been shown that slow addition of epoxide from carbon tetrachloride solution to cotton fabric impregnated with dilute alkali, natural salts, or alkaline salt solutions produces a fabric of good dry and wet crease recovery. Rapid addition of epoxide to fabric by the use of more concentrated alkali or elevated temperature showed excellent wet, but no dry, crease recovery. Hydrogen ion catalysis of the BDE–cotton reaction is very slow and, in the case of acetic acid, is without effect. With sulfuric acid, only mediocre wet crease recovery is produced a t room temperature. Catalysis with zinc fluoborate, methanolic solutions of BDE, and curing temperatures of 75–125° resulted in excellent wet and dry crease resistance a t weight gains of less than 2%. All methods of BDE addition to cotton fabric that produce good dry crease recovery cause a lowering of tearing and breaking strengths. There is little change in tensile properties when only wet. crease resistance is imparted. This suggests that profound physical changes in the fine structure of cellulose result from mild chemical action with a water‐soluble diepoxide. Recovery from deformation of cotton fibers in the wet and dry states (crease recovery) has been attributed to intermolecular covalent crosslinking of anhydroglucose unit hydroxyls by the diepoxide and, in particular, to crosslinking of hydroxyls on carbons 2 or 6, with a resultant diminution of interchain slippage. Fibers that exhibit only wet crease recovery are believed to have a minimum of covalent crosslinks and to be hydroxy cellulose monoethers of the epoxide or graft polymers of the same, which prevent slippage of chains only when wet and swollen (possibly by entanglement).

The Nature of Wet Crease Recovery in Cotton—A Review

“…Microscopists usually speak of degrees or levels of cross-linking, meaning that some derivatives of a low degree of substitution swell more than do those with higher D.S. The Form D and Form W processes for treating cotton are cases in point, as is also treatment with BDE ( meso-butadiene diepoxide) [40]. From the electron micrographs in this latter work it was shown that different degrees of dissolution and swelling occurred with samples having the same crease angles.…”

“…' 4. E~o.rides and Wet Creasr R~~oz~c~r~Õ ne must exercise care in comparing epoxide finishes with formaldehyde finishes, because here we are dealing with a class of compounds that vary widely in reactivity for reasons pointed out previously [36,38,40].…”

The Treatment of Cotton with Ammonia-Epichlorohydrin Reaction Products

“…Due to the pseudo basicity of epoxides, hydroxyl ions are generated after the initial r~ng openings by chloride ions, and this can be considered as an alkaline catalyzed reaction. Certain epoxides have been found to add to cotton cellulose when catalyzed by 1 M NaCI under these conditions [13]. At reasonable add-ens, there was little irn-…”

“…In one series, the fabric was pretreated by twice padding to approximately 95% wet pickup with an aqueous solution of catalyst (NaOH or salt) and then immersed in a CCI, solution of the triepoxide. Previously, similar application of butadiene diepoxide had produced the desired results [2,13].…”

Effects of salts, solvents, and substituents on the reaction of cellulose with epoxy compounds

“…Actually, McKeZvey et al 3,13) have found that the percentage of "add-on" for yarns treated with a 20% solution of 1,2,3,4-diepoxybutane in carbon tetrachloride for 16 h at 26°C increases linearly with the increase in activity of the OHion up to a maximum, which is reached at concentrations of sodium hydroxide between 13 and 15%. Tab.…”