Clark M. Welch

Tetracarboxylic Acids as Formaldehyde-Free Durable Press Finishing Agents: Part I: Catalyst, Additive, and Durability Studies1

1,2,3,4-Butanetetracarboxylic acid and all-cis-1,2,3,4-cyclopentanetetracarboxylic acid have been studied as durable press reagents for cotton. They quickly form ester-type crosslinks in the cellulose when applied to fabric by pad-dry-cure techniques. Weak bases have proven to be active catalysts, one of the most effective being mono-sodium phosphate. Durable press smoothness ratings of 3.8–4.4 were imparted by either tetracarboxylic acid. The amount of tetracarboxylic acid required could be decreased by two-thirds by having citric or tartaric acid present as a co-reactant additive. In durability to home laundering, finishes from butanetetracarboxylic acid far surpassed those from cyclopentanetetracarboxylic acid, and most of the durable press performance was retained through 65 washing and drying cycles with a wash temperature of 50°C (122°F) and a pH of 9.8 using a standard detergent. The strength retentions, bending moments, and wrinkle recovery angles of treated fabric were comparable to those imparted by dimethyloldihydroxyethyleneurea.

Low, Medium, and High Temperature Catalysts for Formaldehyde-Free Durable Press Finishing by the Glyoxal-Glycol Process

Improved catalyst systems have been developed for use in the glyoxal-glycol process under a wide variety of curing conditions. The mild cure process, now conducted with polyethylene as fabric softener in place of the reactive hydrophobic silicones formerly required, takes place at 120-125°C in 2 minutes by aluminum sulfate catalysis in the presence of tartaric acid. Minor amounts of phosphoric acid are added as needed to counteract fabric alkalinity. The medium cure process at 145-160°C occurs within 15 seconds with the same catalyst and activators in the presence of aluminum dihydroxy acetate as buffer. The high temperature process uses aluminum chlorhydroxide as catalyst in the presence of an α-hydroxy acid, and takes place at 170°C or higher. In all three systems, 1,6-hexanediol is the preferred glycol from the standpoint of durable press performance, fabric strength retention, and fabric whiteness.

The Weathering Characteristics of Lightweight Flame-Retardant Finishes for Cotton Fabrics

The durability to outdoor exposure of eight flame retardants on cotton sateen has been determined, and a study has been made of degradation occurring within the resins. Unexpectedly, several flame retardants applied as coatings showed a longer life than those chemically bonded to the cellulose. Bromme-substituted phosphonitrilate esters were especially durable. and one of these gave a synergistic effect with THPC. The synergism is attributed to a layered structure of the coated and grafted materials on the cotton fibers. In terms of ratio of service life to add-on required. 2,3-dibromopropyl phosphonitrilate and APO were unusually effective. Certain coatings and grafted polymers were stripped intact from the cellulose by weathering processes, while others were degraded to lower-molecular-weight materials subsequently removed. From Apo-treated fabric, the phosphorus and nitrogen atoms were lost in a ratio of approximately 1:2, indicating preferential cleavage pf P—N bonds in the polyner rather than cleavage of polymer-cellulose bonds. The strength of treated fabrics was lower than that of untreated cotton during initial exposures, but a crossover occurred after one year due to inhibition of mildew and decay by all of the flame retardants.

The Bonding of Phenols to Cotton with Zirconium Acetate

Zirconium acetate binds certain phenols to cotton to impart a high degree of rot resistance. Pentachlorophenol, pentabromophenol, methylenebis(p-chlorophenol), and p-hydroxyphenylmercuric chloride have been applied in this way, either as the free phenols or as their sodium salts. This type of treatment has advantages over the simple deposition of phenols on cotton in that the bound phenols are resistant to extraction with water and organic solvents and to removal by abrasion. Besides being rot resistant, the treated fabrics exhibited a good hand, noticeable water repellency, and increased breaking strength, although their tearing strength was usually decreased. Fabrics having appreciable flame resistance resulted when sodium pentabromophenate was applied. Increased weight, softness, and water repellency were obtained on boiling the treated fabrics in soap solutions. This is evidence of an exchange of stearate anions for acetate anions in the polymeric zirconium oxyacetate matrix on the fabrics.

Free Radical Cross-Linking of Synthetic Polymers on Cotton Textiles

A variety of saturated thermoplastic polymers have been cross-linked as interfiber coatings on cotton fabric, without the cotton cellulose. the polymer with catalytic amounts of benzoyl peroxide or 2,4-dichlorobenzoyl peroxide on fabric at 100-165° C caused fixation of the coatings within a few minutes. Polyvinyl esters, acetals and ethers, and linear aliphatic polyesters were used. Copolymers of vinyl chloride with vinyl esters and with alkyl acrylates were also found applicable. The efficiency of polymer insolubility was 60-80% and was independent of the fabric used. whether cotton, glass, paper. Orlon,2 nylon, Dacron,3 or acetate rayon, Grafting of polymer to substrate apparently did not occur. Multiple layers of cross-linked coatings were readily formed. Application of poly(vinyl stearate) at add-ons of 4-30% imparted considerable water repellency to cotton and moderately increased the flex abrasion re sistance, while leaving air permeability, breaking strength, and tearing strength essen tially unchanged, Most of the polymer was located in interfiber spaces within individual yarns. Protection of interfiber bonding in cellulose from disruption by water occurred when cross-linked vinyl chloride-alkyl acrylate coatings were used.

The Attachment of Active Hydrogen Compounds to Cellulose With Divinyl Sulfone: Southern Regional Research Laboratory New Orleans 19, Louisiana October 13, 1960

Even large dye molecules have been attached. Irrespective of the kind of active hydrogen compound used, the treated cottons were insoluble in cupriethylenediamine, showing that cross-linking occurred along with substitution. In some cases high wet wrinkle resistance and, more rarely, high dry and wet wrinkle resistance were obtained. In the earliest experiments, a solution of the active hydrogen compound and dwinyl sulfone in water or ~ mixed solvent was applied to fabric. The alkaline catalyst could be present in the treating solution or could be applied subsequently to the dried, impregnated cloth. The fabric was then oven-cured. How-

The Use of Bis(Hydroxyethyl) Sulfone in Multipurpose Finishes for Cotton

The use of divinyl sulfone in bonding active hydrogen compounds and active hydrogen polymers to cotton, lvliile simultaneously cross-linking tlie cellulose, was recently denionstrated [j]. Adducts of clivinyl sulfone n i t h aiiiines o r urea also proved effective as bonding agents. arid their tise eliniinated tlie odor and lachryniatioii problems encountered with divinyl sulfone. Fabrics were obtained having wash-wear properties and a variety of other properties imparted by tlie modifying agents attached. I t has now been found that a number of monomeric and polymeric adducts of water with divinyl sulfone may be used as the bonding agents in this process. Dis (2-hydrosyetlipl) sulfone, wliicli is available coinmercially as a wasli-wear finishing agent, has proved especially effective in attaching amines, phenols, and alcohols to cellulose. I t also readily attaches to cotton those silicones that contain =Si-H groups. Tlie attachment and cross-linking reactions taking place may be represented as follows :

Chromatography of substituted anilines on 3,5-dinitrobenzoyl paper : An example of organic charge-transfer chromatography

Simple and substituted anilines are adsorbed by 3,5-dinitrobenzoyl (DNB) paper, a potential polymeric charge-transfer acceptor. The formation of distinct colors observed when DNB paper was contacted with various anilines (donors) is consistent with the hypothesis that charge-transfer interactions play an important role in the binding of these components to DNB paper. The RF values from organic solvents could be correlated with the Hammett substituent constant (%), in the case of electron-releasing substituents. Differences in RF values were sufficient to permit chromatographic separation of some of the substituted anilines, indicating that DNB cellulose is a useful chromatographic medium.