Ralph J. Berni

Comparison of Properties of Anion-Exchange Cottons in Fabric Form

The effects of the substitution of various types of amino groups in cotton on the crease recovery properties have been investigated. The potentiometric titration curves of the various aminized cottons have been used to differentiate the presence of quaternary ammonium groups (strong-base anion exchangers) from the presence of primary, sec ondary, or tertiary amino groups (weak-base anion exchangers). Weak-base anion exchange cottons have been quaternized by treatment of cotton containing tertiary amine groups with methyl iodide and with epichlorohydrin. In addition, strong-base exchangers have been prepared directly by a one-step process in which cotton pretreated with a base is reacted with a mixture of epichlorohydrin and a tertiary amine at a 3: 1 molar ratio. Weak-base aminized cottons containing primary amino groups have been reacted with epichlorohydrin in the presence of an aqueous base to form cottons of improved dry- and high wet-crease resistance. Only those quaternized cottons prepared from the reaction of pure epichlorohydrin on cottons containing tertiary amine groups possessed both high dry- and improved wet-crease recovery properties. Equations are given to illustrate types of reactions investigated and mechanisms of reactions.

Kinetics of the Reactions of Ethyleneurea Derivatives with Cotton Cellulose Part II: The Cellulose—Bimethyloldihydroxyethyleneurea Reaction

The kineties of the reactions of cotton print cloth treated with 0.55 M solutions of 4.5-dihydroxy-1,3-bis(hydroxymethyl)-2-imidazolidinone (dimethyloldihydroxyethylene urea) in the presence of 0.03 M inorganic salt catalysts have been investigated. The present two-stage delayed-cure process for chemically modifying the performance of cellulosic fabrics depends on the significant differences in reactivities of cellu lose with methylol functional groups and with the hydroxyl groups of the urea derivatives. Specific reaction rate constants at 45, 55, 65, 75, and 85°C in the presence of ZnCl2, Zn(NO3)2, MgCl 2, and Mg(NO3)2 have been calculated by following the changes in nitrogen and formaldehyde contents and the changes in crease recovery properties of finished fabrics. These rates have been compared with those determined when cotton retets with an etherifying agent having ring hydroxyls only, as in the cellulose-dihydroxy ethyleneurea reactions, and with those determined when the etherifying agent has methylol hydroxyls only, as in the cellulose-dimethylolethyleneurea reactions. Enthalpies, entropies, and free energies of activation have been compared.

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.

Esterification of Cotton with Certain Monofunc tional Acid Chlorides and the Effect on Crease Recovery

It has been demonstrated that conditioned (dry) crease recovery of cotton fabric can be increased by partial esterification with monofunctional acid chlorides in dimethylform amide. In the range of C8 through C18 acid chlorides studied, the increase in dry-crease recovery varies linearly with the chain length of the added acyl group. Both odd- and even-numbered acyl groups and unsaturated and geometrical isomers have been con sidered. The unsaturated C18 acid chlorides, oleoyl and elaidoyl, were found to be more effective than saturated C18 acid at a similar D.S. The increase in conditioned crease recovery is suggested to be due to esterification in a nonaqueous medium at originally favored water adsorption sites in less ordered regions.

The Preparation and Properties of Partially Benzylated Cotton

Ternary systems, such as alcohol. water, and sodium hydroxide, have been used in the pretreatment bath or have been added in fixed quantities to cotton prior to etherifi cation with benzyl chloride. Evidence has been obtained which supports an hypothesis that increased reagent solubility, coupled with control of the cellulose: sodacellulose equilibrium. can lead to essentially homogeneous cotton cellulose modifications. In addition, the experiments have resulted in the preparation of interesting fibrous cellulose ethers. These ethers retained many of the desirable mechanical properties of the original cotton and showed increases in elastic recovery, decreased permanent set, sub stantivity to disperse dyes, microbiological resistance, and a high degree of thermo plasticity.

Chemical Composition of Cotton-Processing Dusts

Inorganic and proximate compositions were determined for total and fine (under 20 μm diameter) dusts from cotton gins, textile mills; oil mills, and cotton compresses. The ash content of fine dusts was higher than that in total dust samples but decreased with the stage of processing in textile mills and gins. Inorganic composition often differed exten sively and appeared to depend on the soil composition and growing location. Large differences in water solubility and protein content also were observed. The difference between total and fine cardroom dusts was primarily in fiber content. Numerically and gravimetrically, the vast majority of mineral particles and plant fragments in carding dust appeared to be under 20 μm diameter. Little difference was found in the relative ratios of inorganic elements and nonfiber plant fragments in total and fine gin dust samples. Differences in dust composition Were often greater from one gin, mill, or compress to another than those among samples obtained at different stages of processing within the same plant,

Collection of Large Quantities of Respirable Cotton Dust for Byssinosis Research

Byssinosis is an occupational respiratory disease which is thought to be induced by chronic respiration of cotton, flax, or soft-hemp dusts in textile mills. The disease is caused by foreign matter included with the raw fiber, not by the fiber. Obtaining sufficient quantities of respirable dust under 15–20 μm diameter for biological and chemical analysis has been a major difficulty in byssinosis research. Two simple means have been devised for collecting kilogram quantities of respirable cotton dust from the air-cleaning systems in commercial mills.

A New Theory of Resiliency in Cotton

Chemically modified cottons having crease resistant properties that are not anticipated on the basis of currently accepted theories of crease resiliency are discussed. Specific inconsistencies are cited between theory and experimental data obtained from cotton treated with (a) inert solvents, (b) epoxy compounds capable of reacting with fibers preswollen in aqueous base, (c) long chain monobasic acid chlorides in selected nonaqueous media, and (d) monomers or prepolymers capable of cross-inking or being deposited or grafted. The importance of developing a new theory for mechanisms of conditioned and wet crease resiliency in cotton is emphasized and it is suggested that the development of such a theory must consider such important factors as the (a) overall hydrogen-bonded network of native cotton and chemically modified cottons, (b) the role of tightly bonded water in the original network, (c) energy changes which necessitate formation of a new hydrogen-bonded network simultaneously with disruption of the native network, (d) entropy changes involved when water molecules re-enter a chemically modified cotton from either the vapor state or bulk liquid state of water, and , (e) capabilities of chemical substituents or physically deposited polymers within or on cotton fibers acting as acceptors or donors in formation of new hydrogen-bonded systems.

3-Hydroxymyristic Acid as a Measure of Endotoxin in Cotton Lint and Dust

A series of samples consisting of purified cellulose, purified cellulose spiked with endotoxin, and cotton lint and dust samples from the Human Panel Acute Exposure Studies at Clemson, South Carolina, were extracted with pyrogen-free water and with phenol-water. Phenacyl esters of the dried, hydrolyzed extract were prepared and chromatographed on a high performance liquid chromatograph. A peak assigned to the phenacyl ester of 3-hydroxymyristic acid appears in the chromatograms of extracts of celluloses that have been spiked with endotoxins and not in those of unspiked celluloses. This peak also appears in the extracts of cotton lint from samples that cause the greatest decrement in lung function in the Clemson human exposure studies. The area of this peak increases with increasing amounts of endotoxin and may serve as a measure of endotoxin concentration in cotton lint and dust, at least when fairly high levels of endotoxin (0.50 micrograms or greater) are present. The effect of extraction method on the determined amount of endotoxin is discussed.

Durability of Oleophobicity of Cotton Fabrics Imparted by Fluorochemicals

Durability of oleophobicity imparted to cotton fabries by additive finishes (perfluorometallic complexes and perfluoro-acrylate) and hy the incorporation of fluorochemicals into the cellulose molecule by means of an ether linkage has been investigated. Studies on the relative effectiveness of additive finishes in maintaining oleophobicity on weathering have been made. Results of soil burial tests involving the use of aluminum triacetate and perfluorooctanoic acid on various fabric constructions are reported. Various techniques used in efforts to improve durability of the latter finish to aqueous laundenngs are described. Data are presented to explam losses in oleophobic properties when fabrics treated with perfluorooctanoic acid complex of chromium or aluminum are subjected to aqueous launderings. The preparation of 1,1-dihydroheptafluorobutoxyhydroxypropyl and 1,1-dihydropentadecafluorooctoxyhydroxypropyl ethers of cellulose which possessed hydrophobic and oleophobic properties durable to alkaline aqueous washings and commercial drycleaning solutions are described. The preparation of 1,1,7-trihydrododecafluoroheptoxyhydroxypropyl ether of cellulose which possessed only a small degree of oil repellency due to the presence of an omega-hydrogen atom is also