Norton A. Cashen

Methanesulfonic Acid as Catalyst in Durable-Press Treatments of Cotton

Methanesulfonic acid, because of its similarity to hydroxymethanesulfonic acid, has been investigated as a catalyst for finishing cotton to produce durable-press properties. It provides strong catalysis in mild cure and conventional pad- dry-cure treatments. However, fabric must be washed after treatment to remove residual acidity which otherwise causes undesirable changes in the finish.

Strong Lewis Acid Salts as Catalysts in Mild-Cure Finishing Treatments for Wrinkle Resistance

Lewis acid salts have been investigated in place of mineral acids as catalysts for wrinkle resistance treatments of cotton fabric with dimethylol methyl carbamate under mild-cure finishing conditions. Salts that are strong Lewis acids, such as aluminum chloride, aluminum nitrate, aluminum sulfate, and stannic chloride, produced finishes essentially equivalent to those of mineral acid catalysis when curing was conducted at 100°C. With curing at 60°C, however, the mineral acids are much more effective catalysts. Zinc chloride, zinc nitrate, and magnesium chloride, the catalysts widely used in con ventional pad-dry-cure finishing treatments, are weaker Lewis acids and are not suitable for mild-cure finishing.

Carbohydrazide as a Formaldehyde-Scavenging Agent in Durable-Press Finishing

Carbohydrazide has been demonstrated to be an efficient formaldehyde-scavenging agent, particularly with dimethyloldihydroxyethylene urea (DMDHEU) resins. With a given level of carbohydrazide, a lower level of free formaldehyde was achieved with the buffered DMDHEU resin than with the unbuffered. The nature of the catalyst also had a significant effect on the formaldehyde-scavenging ability of the carbohy drazide. Although the free formaldehyde is reduced on the fabric initially, it increases after washing. A solution of the carbohydrazide in the methylated DMDHEU has long-term stability. This property would permit a preformulated product by the resin manufacturer.

Effects of Carbohydrazide on Volatiles Released During Finishing with THPOH-NH 3 and Attendant Decrease in Shade Changes of Reactive-Dyed Cotton Fabrics:

Ammonia treatment of fabric impregnated with THPOH and a small amount of carbohydrazide produced a flame-retardant fabric that had higher weight gains and higher phosphorus, nitrogen, and formaldehyde contents than a treated fabric in which the carbohydrazide was absent. The carbohydrazide has ability to react with both the organophosphorus moieties as well as free formaldehyde, yielding products of relatively low volatility that are not lost during the drying and ammonia curing steps. The decreased formaldehyde released during drying lessens the change in shade of cotton fabrics dyed with reactive type dyes that is usually observed when they are treated for flame resistance with THPOH-NH3.

A New Concept in the Reduction of Free Formaldehyde Associated with DMDHEU Easy-Care Finishing of Cotton

Upon addition of carbohydrazide to a commercial DMDHEU solution, formalde hyde is arrested in the form of an insoluble condensation product that can be removed by centrifugation or filtration. Cotton finishes obtained from pad baths prepared from a modified commercial DMDHEU resin exhibit a dramatic reduction in free formal dehyde and a greatly increased stability against the kind of hydrolytic cleavage of the N-C bond that normally leads to increased formaldehyde release after laundering of a conventional DMDHEU-treated cotton.

Multifunctional Applications of Hydrazides in Flame-Retardant and Durable-Press Finishing of Cotton

Research reported by Cashen ~1~ has described a flame-retardant,’ bacteriostatic, multifunctional finish for cotton that was obtained by the in silu polvcondensation of TI;iPOH-NH3 and 10-undecenoic acid hydrazide. This finish meets FF 5-74 standards for nonflammability after 50 cycles of laundering (Table I). In another study ~2~ carbohydrazide, (H.~N ~ NH)l C:O, has been used in lieu of the fatty-acid hydrazide in the polycondensation with THPOH-NH3, producing

Ammoniation of Wet Fabric in the THPOH-NH3 Process

Ammoniation of wet fabric padded with THPOH offered a possible solution to certain odor problems associated with the THPOH-NH3 process. A flame-retardant product that was not durable to extensive laundering was produced by ammoniation of wet fabric padded with THPOH. Reasons for nondurability of polymer and the role of the moisture in polymer Jocation in the fiber are reported.

The Electrostatic Properties of THPOH-NH3 Flame-Retardant Cotton Fabric as They Pertain to Potential Mill Problems and Performance Properties

A THPOH-NH3-treated flame-retardant cotton fabric has been shown to have an increased capacity to hold an electrostatic charge in comparison to untreated cotton fabric. Increased cling and frictional tendencies of the treated yarn, as well as increased wet soil deposition and retention in the treated fabric, have also been observed.

Isolation and Qualitative Characterization of Some of the Water-Soluble By-Products of THPOH-Ammonia Polymer Synthesis

The side reactions of the polymerization of tetrakis(hydroxymethyl)phosphonium hydroxide-ammonia (THPOH-NH 3) for flame-retardant treatment of cotton textiles yield water-soluble products. This report attempts to answer some of the questions which relate to the kinetics and thermodynamics of these side reactions and to characterize some of the products. Hexamethylenetetramine was established by adsorption chromatography and by internal reflection infrared spectroscopy as a competing side-reaction product. Also, aminomethanol and hexahydro-1,3-5-triazine are strongly suggested as associated intermediate compounds.

Chromatographic Separation of the Lyophilized Reaction Products of Formaldehyde and Methyl Carbamate

A mixture of the condensation products obtained from formaldehyde and methyl carbamate, prepared in an aqueous medium according to the procedure of Reid and coworkers, was studied and its components tentatively identified. The mixture was lyophilized, and birefringence under polarized light showed that the solid product was comprised of mixed crystals. These crystalline products were then separated as essentially pure compounds by thick-layer chro matography: mass spectra of the chromatographic eluates contained masses 279, 284, and 137 that appear to be molecular ions, and a mass of 129 that is possibly a fragment of a linear dimer.