Hilda M. Ziifle

Investigation of the Catalyst in the Cellulose-DMEU, Reaction Part I: Effect of Catalyst upon the Physical and Chemical Properties of the Finished Cottons'

Cotton print cloth (80 X 80) has been treated with 8% solutions of DMEU in the presence of inorganic salt catalysts at constant molar concentration of the metallic ion. The four catalysts employed—MgCl2, Zn(NO3)2, Mg(NO3)2, and ZnCl2—were studied at 0.006 M, 0.03 M, and 0.1 M concentrations. A comparative study has been made of the physical and chemical properties, swelling behavior as revealed by microscopical techniques, and infrared absorption spectra of all specimens. It has been found that absorption spectra differ with treatment, depending on the absence or presence of a catalyst; that the catalyst enters into the reaction; and that the final properties of the treated fabrics are influenced by catalyst concentration. Consideration is also given to the effect of catalyst upon chlorine damage.

Physicochemical Study of the Cotton Cellulose— Dimethylolpropyleneurea Reaction1

Physical and chemical properties of cotton print cloth treated with 0.55 M solutions of 1,3-bis(hydroxymethyl)-2(1H)-tetrahydropyrimidinone (dimethylolpropyleneurea or DMPU) in the presence of 0.03 and 0.1 M inorganic salt catalysts have been determined. The kinetics of the reaction in the presence of 0.03 M catalysts have been investigated. Specific reaction-rate constants at 45, 55, and 65°C in the presence of ZnCl2, Zn(NO 3)2, MgCl2, and Mg(NO3)2 have been calculated by following the changes in nitrogen and formaldehyde contents. Changes in crease recovery properties of finished fabrics with changes in nitrogen and formaldehyde contents were also followed. Enthalpies, entropies, and free energies of activation at 45°C for the reaction have been calculated. Specific reaction-rate constants and activation parameters were compared with those values reported previously for the reactions of cotton with derivatives of ethyleneurea. Infrared spectral data of fabrics finished with DMPU were analyzed.

Changes in Fine Structure of Cotton Modified With Butadienediepoxide—Spectral and Microscopical Studies

This paper presents results of spectral and microscohical studies designed to relate observed differences in fabric properties to changes detected in fine structures of cottons chemically moditied with d,l-isomers of butadienediepoxide (BDO) under conditions of base catalysis. Cottons pretreated with aqueous NaOH (2% to 23%) can be etherified with BDO in CCl4 while the fibers are in a wet and swollen condition at room tempera ture. with the resultant production of fabries possessing both high dry- and high wet- crease resistance. All concentrations of base pretreatments caused increased wet crease recoveries at low ad-ons of BDO. High dry crease recoveries were obtained at low add-ons only on fabries pretreated with dilute NaOH. For 10% to 15% NaOH pre treatments. higher add-ons of BDO were needed to impart high dry as well as high wet recovery. X-ray diffraction tracings indicate structural differences related to caustic pretreatments, and infrared spectral changes, coupled with x-ray data, suggest changes in cellulosic reaction sites with changes in reaction conditions. Microscopical examinations indicate formation of BDO cross links after all pretreatment conditions, but reflect differences in swelling behavior as a result of base pretreatment.

Effect of Mercerizing- Strength NaOH on Fine Structures of Cottons Modified with Butadienediepoxide

Spectral and microscopical data revealed effects of 23% NaOH used either as a pretreating agent (catalyst) or as a mercerizing agent prior to or subsequent to treatment of cottons with CCl4 solutions of butadienediepoxide (BDO) in presence of more dilute NaOH catalysts. Whereas high dry and high wet wrinkle-recovery angles resulted when 2% or 15% NaOH catalyzed the BDO-cellulose reaction, only high wet recoveries were obtained with 23% NaOH catalysis. Conditioned recovery angles were higher, the weaker the base pretreatment. Postmercerization did not change recoveries of BDO- native cottons catalyzed by 15% NaOH but adversely affected dry angles of BDO-treated fabrics catalyzed with 2% NaOH and wet angles of those fabrics from reactions catalyzed by 23% NaOH. BDO-native cotton fabrics under 2% base catalysis retained the cellu lose I lattice; those under 15% NaOH catalysis exhibited mixed cellulose I- and II-type lattices, and those under 23% base catalysis consisted of mixed cellulose II- and III-type latices. Postmercerization resulted in (1) a cellulose IV-type lattice from BDO-treated fabrics which originally retained the native cellulose I structure, (2) a mixed cellulose II and IV-type lattice for those which originally possessed the mixed cellulose I- and II-type structure, and (3) no further effect upon those which originally possessed a mixed cellulose II and III-type structure. , Mercerized fabrics (mixed cellulose I and II) pretreated with aqueous NaOH and then reacted with BDO exhibited high dry and high wet wrinkle-recovery angles only when 2% NaOH catalyzed the reaction, and then only when add-ons of BDO were ex tremely high (35%). Otherwise, dry recovery remained essentially that of the mercerized control, and only high wet recoveries were obtained. Comparisons of fabric properties of BDO-mercerized cottons were made with those of the BDO-native cottons. Only with 23% NaOH pretreatment did comparable products from BDO-native cotton and BDO-mercerized cotton reactions have the same lattice type and show a tendency toward a cellulose III-type lattice. Microscopical and spectral data indicate the mixed I and II lattice was retained in all BDO-mercerized cottons pretreated with 2% NaOH and in all cottons pretreated with 15% NaOH or 23% NaOH and reacted to low add-ons of BDO. Postmercerization of these BDO-mercerized fabrics converted the cellulose I lattice to a II rather than to a IV-type lattice as occurred in BDO-native cottons. With those fabrics of high BDO add-ons postmercerization changed the cellu lose II-type lattice to a cellulose III lattice.

A Comparative Study of Cross-Linked Kiered, Mercerized, and Decrystallized Cotton Yarns and Fabrics:

Kiered, slack-mercerized, tension-mercerized, and ethylamine-decrystallized cotton yarns, as well as 80 X 80 fabrics woven from these four modified yarns, were subjected to treatment with a melamine-formaldehyde finishing agent under varying conditions of tension during the drying and curing steps. The physical and mechanical properties of the cross-linked products were compared with those of the untreated control materials and with each other. Resin treatment produced similar effects upon the properties of - the decrystallized and those of the slack-mercerized yarns and fabrics. Tension applied during the drying and curing stages of the resin treatment affected the final properties of the finished product. In general, the greater the tension applied to yarns, the greater the retained breaking strength and elastic recovery but the less the elongation at break. Tension applied in this study dur-ing the drying and curing of the resin-treated fabrics adversely affected the elongation at break but was not sufficient to effect improvements in strength and recovery properties over those of similarly treated fabrics dried and cured under slack conditions.