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Two t-amino-N-methylol reagents, 2(diethylamino)ethyl N,N-di(hydroxymethvl)carl)amate and dimethyloldi ethylaminopropyltriazone, were prepared, and their reactivities in finishing of cotton fabrics were characterized. Auto- catalysis was shown by these reagents when they were applied as hydrochlorides to cotton fabric and given a conventional pad-dry-cure; however, full development of resilience was not realized unless the pH of the reagent solution was lowered to 1.0. The sluggish reactions of the t-amino-N-methylol reagents are discussed; the stronger-than-normal catalysis that was required counterbalanced potential protective effects from the t-amino groups to lessen acid degradation during finishing reactions. [ABSTRACT FROM PUBLISHER]

Textile properties of the cured fabric resulting from the wet-fixation process are functions of the duration of the fixation step. As duration of this step is extended with reagent systems involving dimethyloldihydroxyethyleneurea together with highly methylated hexamethylolmelamines, resilience of cured fabric is high and constant, whereas Stoll flex abrasion resistance and breaking strength (strength properties) show progressive increases. This is evidently the first observation of increasing strength properties at a constant high level of resilience during a durable-press finishing process. The development of strength properties is considered to be critically dependent upon the penetration of reagent into the fabric, yarns, and fibers for reaction on elementary structural units of the cotton fibers. This unique degree of penetration to the less accessible regions in cotton fibers is believed to relieve internal strains within the fibers before crosslinking takes place. Other features of the mechanism of develolment of strength properties in durable-press cottons are discussed. [ABSTRACT FROM PUBLISHER]

Chemically modified cottons resulting from reactions of hydroxymethylmethylethyleneurea (HMEU) and methoxymeihylmethyletbyleneurea (MMEU) with cotton fabric at 160°C by zinc nitrate catalysis were studied. From these cottons modified with the monofunctional analog of dimethylolethyleneurea (DMEU) positive evidence was found for the presence of trapped dimer of HMEU and for oxymethylene linkages in addition to the expected methyleneethyleneurea substituents. The estimate is: for approximately 1% of bound nitrogen or 4% add-on of HMEU, half of the nitrogen is present as the methyleneethyleneurea substituents; the remaining nitrogen is primarily dimer of HMEU; and 0.1% formaldehyde (on weight of fabric) is present as oxymethylene linkages. This estimate corresponds to 0.2 mol of oxymethylene linkages and 1 mol of trapped ethyleneurea units per mole of covalently attached methyleneethyleneurea substituents. The results are discussed relative to structures developed when cotton is treated with DMEU. [ABSTRACT FROM PUBLISHER]

Hydroxy acids were used as coreactant catalysts with N-methylol crosslinking reagents to produce recurable durable-press cotton fabrics. The resilience and strength retention properties of these fabrics were equivalent to or slightly better than those of durable-press fabrics cured with a conventional curing catalyst. All fabrics tested with gluconic acid had low carboxyl contents, whereas fabrics treated with glycolic, lactic, and tartaric acids had carboxyl contents that varied with the methylol reagent. The recurabilities of these fabrics were measured by a creasing and crease durability test. Fabrics cured with a conventional catalyst and the fabrics cured with gluconic acid had very little or no recurability. Fabrics treated with dimethyloldihyroxyethyleneurea and the other hydroxy acids had excellent recurabilities. Fabrics treated with a urea-formaldehyde regent had poor recurabilities, and those treated with a methylol melamine reagent had good to fair recurabilities. [ABSTRACT FROM PUBLISHER]

Cotton twill fabric was treated by a pad-dry-cure process with combinations of DMDHEU and several potycarboxytic acids. Fabrics were prepared with several ratios of catalytic rarhoxylic acid groups to DHEU residues in the modified cellulose. The wrinkle-recovery angles, durable-press appearance ratings, and strength retentions of these fabrics were equivalent to or slightly better than those imparted by the conventional DMDHEU-MgCl2 treatment. The fabrics were analyzed for nitrogen, formaldehyde, ester linkages, and free carboxytic acid groups. The ratios of formaldehyde residues to DHEU residues in the cured experimental fabrics decrease with increasing wrinkle-recovery angles of the fabric. These fabrics showed very good recurahility when prepared with selected polycartroxylic acids, e.g., citric, cyctopentanetetra cartroxylic, and tetrahydrofurantetracarboxylic acids. The rerurahility was lost by converting the free carboxyl groups in the fabric to salt forms, but was restored when the free carboxyl groups were regenerated. [ABSTRACT FROM PUBLISHER]

The times of formation and the yields of gel obtained by hydrochloric acid-catalyzed polymerization of five methylo lated melamines were determined at 25°C and 82°C. The substitution of the amino groups of the melamines ranged from trihydroxymethyl- to monohydroxymethylpentamethoxymethylmelamine. Homopolymerization and copolymer ization of these melamine reagents with dimethyloldihydroxyethyleneurea (DMDHEU) was studied for the purpose of optimizing the conditions and clarifying the roles of these reagents in the wet-fixation, durable-press process for modifying cotton textile fabrics. Polymers formed at gelation were characterized by their ir spectra and by formaldehyde-to- nitrogen ratios. The significance of this work relative to the wet fixation process is discussed. [ABSTRACT FROM PUBLISHER]

N-Ethyl-N-(2-chlorciethyl)aziridinium chloride, the water-soluble intermediate formed from N-ethylbis(2-chloroethyl)- amine, was found to be sufficiently stable to allow bake-cure as well as wet-cure crosslinking of cotton. An examination was made of the effects of wet-cure (25°C) vs bake-cure (120°C and 140°C) crosslinking upon the structures of the reagent residues (i.e., the fractions of simple substituents, simple crosslinks. and complex structures) and upon the sites of attach ment of reagent residues to the glucose units of the cellulose chain. The fraction of simple crosslinks was similar in products of both wet- and hake-cure reactions; however, the fraction of simple substituents was higher and the fraction of complex products was lower in the cotton modified by bake-cure reactions. The predominant crosslinks in all cases were those with 2,6'-O-linkages (i.e., from the hydroxyl at C-2 in one glucose unit to the hydroxyl at C-6 in another glucose unit). [ABSTRACT FROM PUBLISHER]

A recurability test, consisting of a standard ironing to impart a crease, followed by laundering and visual rating of the remaining crease, was developed and applied to cotton fabrics which had been treated with combinations of a methylol crosslinking reagent and a polycarboxylic acid. These fabrics were recurable to a much greater extent than fabrics treated with a conventional metal salt catalyst. A series of ten methylol reagents, when used with polycarboxylic acids, showed a direct relationship between recurability and wrinkle-recovery angle in the treated fabrics. Dimethyloidihydro xyethyleneurea was the best of these reagents in both respects. [ABSTRACT FROM PUBLISHER]

Diethylaminoethyl (DEAE)-cellulose, prepared at low DS and without change in crystallinity from that of the original cottons, was subjected to hydrolysis with 2.5 N HCI for various lengths of time ranging from 20 min to 5 hr. The yield of DEAE-hydrocellulose (insoluble fraction) ranged from 90.5% at 20 min to 79.2% at 5 hr. Throughout the hydrolysis, the percent nitrogen in the solubilized fraction was triple that in the insoluble fraction. Gas-liquid chroma tographic analysis to determine the distribution of substituents in the solubilized and insoluble fractions showed that the ratio of substituents in the 2-0- and 6-0-positions was higher in the insoluble fraction than in the solubilized frac tion. The 3-0-/6-0-ratio was higher in the solubilized fraction than in the insoluble fraction. The significance of these results as supporting evidence for two types of accessible surfaces of crystalline elementary fibrils in fibrous cotton cellu lose is discussed. [ABSTRACT FROM PUBLISHER]

The use of N,N-diethylaziridinium chloride (DAC) as a coreactant catalyst for the reaction of cellulose with several N-methylol compounds has been investigated. This catalyst was effective in promoting reaction between cotton and all of the four methylol derivatives tested but especially effective in promoting the reactions of dimethylolethyleneurea and methylated trimethylolmelamine with cotton cellulose. These two cross-linking agents could be used in a delayed- cure process with DAC as the catalyst. Little reaction occurred with either of these reagents during delay periods up to 33 days and no increases in recovery angles were found in the delayed and uncured samples. The delayed-but-cured samples showed crease-recovery angles equal to those achieved in immediate cures. [ABSTRACT FROM PUBLISHER]

The effect of uv light (2537 Å) on the fabric properties of cotton cinnamate was investigated. At the higher degrees of substitution (DS = 0.3 0.6), the cinnamoyl substituents afforded partial protection of the cellulose from photodegrada tion. Cinnamate substituents raised wet and conditioned wrinkle-recovery angles of cotton to the extent of approxi mately 45° and 38° (W + F), respectively, at DS values of 0.48 and 0.58. Irradiation of cotton cinnamates increased both wet and conditioned wrinkle-recovery angles of the fabrics by relatively small amounts up to 36 and 40°, respec tively. These increases are attributed to dimerization between pairs of cinnamate groups with the formation of cross links. [ABSTRACT FROM PUBLISHER]

The gel-permeation technique has been applied to the characterization of cotton cellulose fibers from fabrics cross-linked with formaldehyde in wet-cure and in bake-cure reactions and reduced to a sufficiently small particle size by Wiley-milling. Measurements of total internal water contents, internal solvent volumes, and permeability limits are indicative of the nature and extent of changes in pore structure resulting from the cross-linking. Cross-linked compositions were examined at progressively higher levels of formaldehyde which were obtained under the various reaction conditions.The wet-cure processes Forms W and W' involving water-swollen cotton produced only limited alterations of the cellu lose pore structure at the maximum levels of cross-linking attainable by these treatments. Changes in the values obtained for the gel-permeation parameters were small, but the trends show that a larger reduction of internal pore volume is pro duced under the Form W process than under the Form W' process. Reaction with the less concentrated Form W reagents caused a smaller decrease in the permeability limit than Form W'.Large changes in pore structure resulted from cross-linking the cotton in a collapsed state by the hake-cure, Form C. process. The internal pore volumes of both the total and of the effective solvent water contents were reduced with cross- linking over the range from 0.47% to 2.20% methyleneoxy contents of the samples. The permeability limit was reduced from a molecular weight of 2430 for untreated cotton to approximately 1250 at the lowest level of cross-linking. No further decrease of this parameter was produced by cross-linking up to the maximum methyleneoxy content of 2.20%.In all three forms of reaction, the changes produced in total internal water contents followed trends similar to the values for water of imbibition determined by centrifuging. The latter values were larger than those measured chromatographi cally by 34-100%, the discrepancies being larger for the smaller true volumes of internal water calculated from column- volume measurements. The centrifugal technique of determining water of imbibition is a simple procedure for estimating relative changes of internal pore volumes of cottons. [ABSTRACT FROM PUBLISHER]

Tris(2-chloroethyl)phosphoramide prepared from ethylenimine and phosphorus oxychloride was reacted with cotton cellulose in the form of print cloth by a pad-dry-cure process involving a base such as sodium carbonate. Relatively low levels of reaction were achieved with this reagent (less than 10% add-on). Conditioned wrinkle recovery angles of the fabric and structural features of the cross links and reagent residues in the cotton cellulose modified with tris(2-chloroethyl)phosphoramide are compared with those of cotton cellulose modified with tris(1-aziridinyl)phosphine oxide. [ABSTRACT FROM PUBLISHER]

Cotton cellulose modified with tris(1-aziridinyl)phosphine oxide (APO) was prepared with and without zinc fluoborate catalyst. The modified cotton samples were hydrolyzed. Attempts to detect the expected 0-(2-aminoethyl)-D-glucopy- ranoses were complicated by reactions between the functional group at C-1 of the glucose unit and the amine function of the substituent. The ratio of substituents in the 2-0-, 3-0-, and 6-0-positions of the glucopyranosyl units in samples of APO-modified cotton cellulose could be measured when the amino groups were converted to hydroxyl groups by diazo tization prior to hydrolysis. The APO-modified cotton cellulose prepared with zinc fluoborate catalysis and containing 3.08, 5.77, and 14.62% APO exhibited substituent ratios of 0.23:0.21:1.00, 0.29:0.26:1.00, and 0.38:0.37:1.00, respec tively, at the 2-0-, 3-0-, and 6-0-positions. A sample of APO-modified cotton cellulose (6.38% APO) prepared without catalyst exhibited a substituent distribution of 0.65:0.35:1.00. The actual DS values of these samples were estimated to be 0.0040, 0.0071, 0.0084, and 0.0098 for the fabrics containing 3.08, 5.77, 6.38, and 14.62% of incorporated APO, respectively. [ABSTRACT FROM PUBLISHER]

Several samples of tris(1-aziridinyl)phosphine oxide (APO)-modified cotton were prepared with 5.8-14.6% APO in corporation. The samples were degraded by acid hydrolysis and attempts were made to isolate the expected 0-(2-amino ethyl)-D-glucopyranoses and 0-[N-(2-aminoethyl)-2-aminoethyl]-D-glucopyranoses by a variety of techniques. Neither of these glucose derivatives could be detected in the hydrolyzates; however, the hydrolyzates were found to contain a considerable quantity of ethanolamine along with N-(2-aminoethyl)ethanolamine and complex products resulting from reaction of the functional group at C-1 of glucose and the amino compounds derived from the APO during acid hydrolysis. The ethanolamine in the hydrolyzates of two samples of APO-modified cotton was estimated to account for about 85% of the total nitrogen in the samples. The N-(2-aminoethyl)ethanolamine was estimated to account for about 5% of the original nitrogen. The remaining 10% was in the form of polyethylenimines, N-glucosylamine complexes, and glucose substituents. [ABSTRACT FROM PUBLISHER]

Application of gel permeation chromatography, which has been shown to be an effective means of measuring changes produced in the accessibility of decrystallized cotton cellulose by one form of formaldehyde cross-linking [9, 10], has been extended to the study of alterations of the structure of decrystallized cotton produced by intro duction of formaldehyde cross links under various other reaction conditions. These include reaction in aqueous solution (Form W), in the vapor phase (Form V), in acetic acid solution (Form D), each with high and low concentrations of formaldehyde, and in a bake-cure process (Form C). The properties determined by gel permeation chroma tography are the effective internal solvent volume derived from measurements of selective permeability to solutes of decreasing molecular weight and the limit of per meability to solutes of increasing molecular size. Striking differences were revealed in both the nature and magnitude of the alterations of accessibility resulting from differ ent reaction conditions employed for formaldehyde cross-linking. Corresponding changes were observed in gross properties of the cellulose polymer gels, such as the extent of swelling measured by the volumes occupied by the swollen gels per gram of dry solids. Accessibility was increased by reactions in aqueous solution which produced cellulose having larger internal volumes and permeability limits than the unmodified, decrystallized , cellulose. The reaction catalyzed by hydrochloric acid in the acetic acid medium formed products having larger internal volumes, but somewhat lower limits of permeability. Both the internal volume and the permeability limit were decreased by the bake-cure process which produced a polymer having much lower accessibility than the unmodified, decrystallized cellulose. [ABSTRACT FROM PUBLISHER]

Major preceding studies of the distribution of substituents in cellulose have been reviewed. Over-all results indicate that the highest degree of reaction occurs at the hydroxyl group on C-2 in the case of the irreversible Williamson syntheses involving reagents of small molecular size. Pronounced preferential reaction occurs at the hy droxyl group on C-6 in the case of reversible reactions and with increasing molecular size of reagent.The relative reactivities of the hydroxyl groups on C-2, C-3, and C-6 of the D(1→4)- β-glucopyranosyl unit of cotton cellulose have been explored with three chemical agents. Predominant reaction of cotton cellulose occurs at the primary hydroxyl group on C-6 in the case of the reversible Michael addition of methyl vinyl sulfone (i.e., 2-0- : 3-0- : 6-0- = 0.20: 0.03: 1.00), at the hydroxyl groups on C-2 and C-6 in the case of the irreversible reaction with diethylaminoethyl chloride (1.27 : 0.35 : 1.00), and at the hydroxyl groups on C-6 and C-2 in the case of the irreversible Williamson synthesis with sodium allyl sulfate (0.7:0.2:1.0). The D-(1→4)-α-glucopyranosyl unit of dextrin (employed as a soluble model compound for cellulose) undergoes reversible esterification with formic acid most rapidly and to the highest equilibrium level at the primary hydroxyl group on C-6. [ABSTRACT FROM PUBLISHER]

Samples of cotton print cloth were impregnated with 10% solutions of polyethylenimines of various molecular weights, line-dried or oven-dried, and then subjected to ten standard laundering and drying cycles. Analysis for retention of the polyethylenimine (PEI) on cotton fabric through a series of ten laundering cycles showed that substantivity increased with increasing molecular weight of PEI. The effect of oven-drying of PEI-cotton fabric was to increase the retention of PEI over that on line-dried samples; the magnitude of the increase was tmoportional to the moledular weight of the PEI. Fabric properties are described. [ABSTRACT FROM PUBLISHER]