On cotton

Fig. XIII-15. Adsorption isotherm for sodium dodecylbenzenesulfonate on cotton. Curve I, 30°C curve II, 0°C. (From Ref. 64.)...

Reactive xanthene dyes with P-hydroxyethylsulfonyl groups, as exemplified by stmcture (29), provide brilliant shades and excellent washfastness on cotton (40). The sulfutein derivative (29) is synthesized by condensing 3-aminophenol-P-hydroxyethylsulfone with... 

Oligomeric Vinylphosphonate. A water-soluble oligomer, Fyrol 76 [41222-33-7] is produced by reaction of bis(2-chloroethyl) vinylphosphonate and dimethyl methylphosphonate with elimination of all the chlorine as methyl chloride (127,128). This Hquid, containing 22.5% P, is curable by free-radical initiation, on cotton or other fabrics. Nitrogen components, such as A/-methylolacrylamide or methylolmelamines, are usually included in the finish, which can be durable to multiple launderings (129,130). 

There are several methods for introducing the insoluble deposits into the fabric stmcture. The multiple bath method, in which the fabric is first impregnated with a water-soluble salt or salts in one bath and is then passed into a second bath which contains the precipitant, is used most often. Most semidurable retardants used on cotton are based on a combination of phosphoms and nitrogen compounds (25). 

The tetramethylol derivative of DABT, prepared by reaction of DABT with alkaline aqueous formaldehyde, polymerized readily on cotton. It imparted excellent flame retardancy, very durable to laundering with carbonate- or phosphate-based detergents as well as to hypochlorite bleach. This was accomphshed at low add-on without use of phosphoms compounds or antimony(III) oxide (75—77). 

Alaige number of patents cover bis(ben2imida2ol-2-yl) derivatives (9) (48—50). Besides being effective on cotton, compounds of this type show good affinity for nylon. 

A further group of whiteners was found in the acylamino (R,R ) derivatives (16) of 3,7-diaminodibenzothiophene-2,8-disulfonic acid-5,5-dioxide. The preferred acyl groups are aLkoxybenzoyls (72—74). These compounds give a greenish fluorescence and are relatively weak in comparison with stilbene derivatives on cotton however, they show good stabiUty to hypochlorite. 

Stilbene dyes ate classed as a subgroup of azo dyes having excellent colorfastness and typical direct dye wash fastness on cotton and ate arranged iato six categories by the Society of Dyers and Colourists (2), as described ia the foUowiag. 

Textiles. Sorbitol sequesters iron and copper ions in strongly alkaline textile bleaching or scouring solutions (see Textiles). In compositions for conferring permanent wash-and-wear properties on cotton fabrics, sorbitol is a scavenger for unreacted formaldehyde (252) and a plasticizer in sod-resistant and sod-release finishes (253). 

Fibers have been used by humans for thousands of years, but only in the twentieth century has there been such an explosion in fiber types available to the textile manufacturer. The advent of synthetic fibers possessing improved resiliency and dimensional stability has placed natural fibers, particularly cotton (qv), at an ostensible disadvantage. Before synthetics, various means to control the shrinkage, dimensional stability, and smooth-dry performance of cotton had been investigated, but the appearance of synthetics such as polyester has placed a greater sense of urgency on cotton interests to focus on the perceived deficiencies of natural fibers. 

Another approach in chemical finishing is to use reagent systems that are reactive with themselves but only to a limited extent or not at all with the fiber substrate. An example of such approaches are in situ polymer systems that form a condensed fiber system within the fiber matrix (1,2). A third type of approach may be the deposition of a polymer system on the fiber substrate. Once deposited, such systems may show a strong affinity to the fiber and may be quite durable to laundering. Polyacrjiate and polyurethane are examples of durable deposits on cotton, which last through numerous launderings (3). 

For resistance to actinic degradation, the use of certain forms of titanium oxide is an alternative to chrome salts. Another approach has been the use of polymerized methylol melamine on cotton (145). In this case, the action of sunlight leads to gradual breakdown of the melamine polymer after several years. After this, actinic degradation of cotton proceeds as it does in unprotected cotton. 

A number of after-treatments with polyester copolymers carried out after sodium hydroxide processing are reported to produce a more hydrophilic polyester fabric (197). Likewise, the addition of a modified cellulose ether has improved water absorbency (198). Other treatments used on cotton and blends are also effective on 100% polyester fabrics (166—169). In this case, polymeri2ation is used between an agent such as DMDHEU and a polyol to produce a hydrophilic network in the synthetic matrix (166—169). 

Sodium dichromate and various chromic salts are employed in the textile industry (195,196). The former is used as an oxidant and as a source of chromium, for example, to dye wool and synthetics with mordant acid dyes, oxidi2e vat dyes and indigosol dyes on wool, aftertreat direct dyes and sulfur dyes on cotton to improve washfastness, and oxidi2e dyed wool. Premera11i2ed dyes are also employed. These are hydroxya2o or a2omethine dyes in which chromium or other metals are combined in the dye (see Azine dyes DYES Azo dyes). 

Rubber and Synthetic Elastomers. For many years nondecorative coated fabrics consisted of natural mbber on cotton cloth. Natural mbber is possibly the best all-purpose mbber but some characteristics, such as poor resistance to oxygen and ozone attack, reversion and poor weathering, and low oil and heat resistance, limit its use to special appHcation areas (see Elastomers, synthetic Rubber, natural). 

Harvesting. Except for the cotton gin, the introduction of the mechanical harvester has probably had a greater effect on cotton production than any other single event. Commercial mechanical harvesters were introduced into the United States after World War 11. By 1955, about 23% of the cotton was mechanically harvested. That value had increased to 85% by 1965. In the early 1990s more than 99% of the U.S. cotton crop was mechanically harvested, although cotton was stiH hand harvested in some other countries. 

A/-substituted, long-chain alkyl monomethylol cycHc ureas have also been used to waterproof cotton through etherification. Other water repellent finishes for cotton are produced by cross-linked siHcone films (56). In addition to the polymeri2ation of the phosphoms-containing polymers on cotton to impart flame retardancy and of siHcone to impart water repeUency, polyduorinated polymers have been successfuUy appHed to cotton to impart oil repeUency. Chemical attachment to the cotton is not necessary for durabUity oU repeUency occurs because of the low surface energy of the duorinated surface (57). 

Antiredeposition agents contribute to the appearance of washed fabrics. Sodium carboxymethylceUulose [9004-32-4], NaCMC is the most widely used, and on cotton fabrics, the most effective. With the advent of synthetic fabrics, other cellulose derivatives, eg, methylceUulose [9004-67-5], hydroxybutjiceUulose, hydroxypropyl- and mixed methyl and hydroxybutyceUulose ethers have been shown to be more effective than NaCMC (8) (see... 

CeUulases have appeared in a few laundry detergents around the world. Since there are few, if any, ceUulase-based soils present on home laundry, any laundering benefit from ceUulase would be expected to come from action on cotton fabric. The nature and magnitude of such benefits is uncertain (see Enzya s, Ejdusthial Applications). 

Examples of artificially soiled test pieces used to test the performance of amylases include cocoa /milk/sugar, cocoa/sugar/potato starch, cocoa /milk/sugar/potato starch, and starch/carbon black, all on cotton or polyester/cotton. 

Direct dyes azo dyes, and sodium salts, fixing agents, and metallic (chrome and copper) compounds used generally on cotton-wool, or cotton-silk combinations. 

Toxaphene zero 0.003 Kidney, liver, or thyroid problems increased risk of cancer Runoff/leaching from insecticide used on cotton and cattle... 

An older method of cellulose fiber modification is mercerization [22,33-36], which has been widely used on cotton textiles. Mercerization is an alkali treatment of cellulose fibers. It depends on the type and concentration of the alkalic solution, its temperature, time of treatment, tension of the material, and the additives used [33,36]. At present there is a tendency to use mercerization for natural fibers as well. Optimal conditions of mercerization ensure the improvement of the tensile properties [33-35,37] and absorption characteristics [33-35], which are important in the composing process. 

Although the boll weevil, a very serious cotton pest in the South, feeds voraciously on cotton squares and bolls in response to an at-tractant or attractants contained therein, these same cotton parts (49) contain also a boll weevil repellent that shows its effect once the at-tractant has volatilized completely. Department of Agriculture scientists are attempting to isolate and identify this repellent, which presumably could be applied to ward off weevil attack. Cotton seedlings painted with an aqueous emulsion of the material effectively repelled 100% of the weevils for 5 hours and only medium damage was evident after 12 hours, whereas control seedlings were completely destroyed after only 2 hours. 

Studies on the detergency performance and cost optimization of the LAS/AS/ AES have been published [42,43]. Figure 19 shows the performance optimization on sebum soil on cotton cloth and a cotton/polyester permanent press cloth. 

As a result of its use as an insecticide on cotton, fruit trees, vegetables, and other crops, methyl parathion is released directly to the atmosphere during application. It is applied primarily by spraying from aircraft or ground equipment (NPIRS 1986). Aerial application of methyl parathion to agricultural fields releases the insecticide to the air. 

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