Hydrophilic finishes

Various hydrophilic finishes have been used in connection with soil release and soil redeposition during laundering. These finishes can impart a degree of antistatic protection to the treated materials however, the main functions of these finishes are to release soil and to prevent the redeposition during laundering. 

A low fibre-wash liquid interfacial energy is desired, that is a hydrophilic finish is preferred for spontaneous oil roll up. 

A particularly interesting special application of LUROTEX A25 is the hydrophilic finishing of woven and knitted fabrics of synthetic fibres. It improves the moisture transport, so that the fabric is more comfortable to wear and there is less buildup of electrostatic charges. 

Yoo, S., Barker, R.L., 2004. Moisture management properties of heat-resistant workwear fabrics - effects of hydrophilic finishes and hygroscopic fiber blends. Text. Res. J. 74, 995-1000. 

Soane DS, Mill ward DB, Linford MR, Lau R, Green EG, Ware Jr W (2008) Hydrophilic finish for fibrous substrates. US patent 7427300... 

Other Finishes Comfort and the moisture related properties of polyester are of great interest, and finishes and treatments that improve these characteristics should be of great importance in coming years. Polyester fibers can be rendered more water wettable by surface treatment with basic solutions or through application of a hydrophilic finish to the polyester surface. Such finishes improve the water wicking and water transport characteristics of the polyester. Base hydrolysis has the added benefit of giving the polyester a crisp sil k-1 ike hand. Fine denier base-treated polyesters are produced in Japan that are effectively used as a silk substitute. ... 

Uses Wetting agent, detergent, emulsifier, dispersant, cleaning agent for achieving uniform hydrophilic finish on cotton and cotton blends Features Versatile esp. suited for removing min. oil spots, free from APEO and soivs. caustic-stable to 8 Be NaOH Properties Liq. 

Emulsifiers. Removing the remover is just as important as removing the finish. For water rinse removers, a detergent that is compatible with the remover formula must be selected. Many organic solvents used in removers are not water soluble, so emulsifiers are often added (see Emulsions). Anionic types such as alkyl aryl sulfonates or tolyl fatty acid salts are used. In other appHcations, nonionic surfactants are preferred and hydrophilic—lipophilic balance is an important consideration. 

Natural Ethoxylated Fats, Oils, and Waxes. Castor oil (qv) is a triglyceride high in ticinoleic esters. Ethoxylation in the presence of an alkaline catalyst to a polyoxyethylene content of 60—70 wt % yields water-soluble surfactants (Table 20). Because alkaline catalysts also effect transestenfication, ethoxylated castor oil surfactants are complex mixtures with components resulting from transesterrfication and subsequent ethoxylation at the available hydroxyl groups. The ethoxylates are pale amber Hquids of specific gravity just above 1.0 at room temperature. They are hydrophilic emulsifiers, dispersants, lubricants, and solubilizers used as textile additives and finishing agents, as well as in paper (qv) and leather (qv) manufacture. 

Synthetic fabrics can also be finished to achieve a number of specific characteristics (199). For example, increased electrical conductivity can improve the antistatic character of polyester. Similarly, finishes that improve hydrophilic character also improve properties related to soil release and soil redeposition (199,200). 

The principle of blending a conduction fiber with a static-prone fiber has been known for years. A mixture of a substantial quantity (30—40%) of a hydrophilic fiber such as cotton or rayon with a hydrophobic static-prone fiber such as a polyester can produce a static-free blend under ordinary conditions. However, blocking the hydrophilic groups by cross-linking of the cotton with biflinctional reagents such as dimethylolethylene urea or addition of a water-repellent finish such as a sUicone resin increases the static propensity of such a blend. 

Internal surfactant antistats ate physically mixed with the plastic resin prior to processing. When the resin is melted, the antistat distributes evenly in the polymer matrix. The antistat usually has some degree of solubiUty in the molten polymer. However, when the polymer is processed (extmded, molded, etc) into its final form and allowed to cool, the antistat migrates to the surface of the finished article due to its limited solubiUty in the solidified resin. The molecule of a surface-active agent is composed of a polar hydrophilic portion and a nonpolar hydrophobic portion. The hydrophilic portion of the surfactant at the surface attracts moisture from the atmosphere it is the moisture that has the static dissipative effect. 

The principal problems for sdicone mbber as a viable lens material are the nonpolar nature, which gives Hpid deposits and wettabdity problems and the tendency to adhere to the cornea. Efforts to modify the sdicone lens surface for improved wettabdity have achieved limited success. These efforts include grafting hydrophilic monomers, such as HEMA, GM (150), and NVP (151—153), to the lens surface and plasma treatments of finished lenses. Efforts to improve the movement of sdicone lenses on the cornea with various lens designs have not been successfld, and the cause of lens—cornea adherence, which is not an exclusive problem of sdicone lenses, is an active area of research. 

The choice of coagulant for breaking of the emulsion at the start of the finishing process is dependent on many factors. Salts such as calcium chloride, aluminum sulfate, and sodium chloride are often used. Frequentiy, pH and temperature must be controlled to ensure efficient coagulation. The objectives are to leave no uncoagulated latex, to produce a cmmb that can easily be dewatered, to avoid fines that could be lost, and to control the residual materials left in the product so that damage to properties is kept at a minimum. For example, if a significant amount of a hydrophilic emulsifier residue is left in the polymer, water resistance of final product suffers, and if the residue left is acidic in nature, it usually contributes to slow cure rate. 

Salts of alkyl phosphates and types of other surfactants used as emulsifiers and dispersing agents in polymer dispersions are discussed with respect to the preparation of polymer dispersions for use in the manufactoring and finishing of textiles. Seven examples are presented to demonstrate the significance of surfactants on the properties, e.g., sedimentation, wetting behavior, hydrophilic characteristics, foaming behavior, metal adhesion, and viscosity, of polymer dispersions used in the textile industry [239]. 

Phenol is the starting material for numerous intermediates and finished products. About 90% of the worldwide production of phenol is by Hock process (cumene oxidation process) and the rest by toluene oxidation process. Both the commercial processes for phenol production are multi step processes and thereby inherently unclean [1]. Therefore, there is need for a cleaner production method for phenol, which is economically and environmentally viable. There is great interest amongst researchers to develop a new method for the synthesis of phenol in a one step process [2]. Activated carbon materials, which have large surface areas, have been used as adsorbents, catalysts and catalyst supports [3,4], Activated carbons also have favorable hydrophobicity/ hydrophilicity, which make them suitable for the benzene hydroxylation. Transition metals have been widely used as catalytically active materials for the oxidation/hydroxylation of various aromatic compounds. 

The essence of any soil-resistant treatment is to render the surface of the fibres more hydrophilic. It also helps if the coating of the fibre is such as to reduce surface irregularity and surface energy. Whilst the two aspects of soil repellency and soil release are interrelated, the actual balance of these properties varies from finish to finish according to requirements. In carpet treatments for example, which are normally given a shampoo rather than washed, the emphasis must be on repellency, whereas soil release becomes of much greater importance in textiles that are frequently washed. 

Essentially nonionic soil-release agents comprise polyesters, polyamides, polyurethanes, polyepoxides and polyacetals. These have been used mainly on polyester and polyester/ cellulosic fabrics, either crosslinked to effect insolubilisation (if necessary) or by surface adsorption at relatively low temperature. Polyester soil-release finishes have been most important, particularly for polyester fibres and their blends with cellulosic fibres. These finishes, however, have much lower relative molecular mass (1000 to 100 000) than polyester fibres and hence contain a greater proportion of hydrophilic hydroxy groups. They have been particularly useful for application in laundering processes. These essentially nonionic polymers may be given anionic character by copolymerising with, for example, the carboxylated polymers mentioned earlier these hybrid types are generally applied with durable press finishes. 

Two basic mechanisms have been proposed to explain the performance of demulsifiers and dehazers in finished fuels. These two mechanisms are defined as coalescence and adsorption. Both processes rely on the fact that the demulsifier contains both hydrophobic and hydrophilic sites. The mechanisms can be defined as follows ... 

Improved Comfort Properties. Wear comfort generally means cotton-like properties, The ability lo absorb moisture from the skin and ihe softness of cotton fabrics are considered to be the two key properties for comfort. The extremely line denier of cotton fibers accounts for its softness. Both properties can be achieved in acrylic fibers. Improved moisture retention can be achieved by incorporating hydrophilic comonomers that decrease ultimate fiher density, by modifying the fiber spinning process, ur by using after-treatments such as modified finishes. 

The use of C02 circumvents the environmental concerns and the worker and consumer health issues associated with perc use. Carbon dioxide is nonflammable and thus does not have the site restrictions often encountered with petroleum. The controlled level of moisture in a C02 system does not damage hydrophilic fibers. And best of all, C02 cleaning leads to a high-quality finished product that is safer for clothes, workers, consumers, and the environment. 

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