Finishing chemicals antimicrobials

A great part of the variation in the final properties of a textile is adjusted for by finishing procedures, for example, wrinkle resistance, soil repellence, hydrophobic properties, flame retardance, and antimicrobial properties [69]. In many cases chemicals are added by padding/ squeezing followed by drying/fixation, for example, in a stenter. 

There has been a variety of approaches for imparting antimicrobial activity to cellulosic fibers, many of them developed as part of a weather-resistant finish (Table I). Metal salts, organometallics, resins, sulfur and nitrogen compounds, and chemical modification of hydroxyl groups by acetylation or cyanoethylation are typical methods used to impart antimicrobial activity (125). A survey made in 1966 lists all commercial products available for protecting materials against biodeterioration— trade names, active ingredients, end uses, and names of manufacturers are tabulated (126). 

Despite the long list of requirements, a variety of chemical fmishes have been used to produce textiles with demonstrable antimicrobial properties. These products can be divided into two types based on the mode of attack on microbes. One type consists of chemicals that can be considered to operate by a controlled-release mechanism. The antimicrobial is slowly released from a reservoir either on the fabric surface or in the interior of the fibre. This Teaching type of antimicrobial can be very effective against microbes on the fibre surface or in the surrounding enviromnent. However, eventually the reservoir will be depleted and the finish will no longer be effective. In addition, the antimicrobial that is released to the enviromnent may interfere with other desirable microbes, such as those present in waste treatment facilities. 

The second type of antimicrobial finish consists of molecules that are chemically... 

Rajan J, Antimicrobial Finishes for Textiles, presented at the Chemical Principles of Textile Finishing Short Course, North Carolina State University, Raleigh, NC, March 1999. 

Specifications for the finished product Two specifications at release and end of shelf-life List general characteristics, specific standards tests and limits for results for the finished product must be provided Analytical test procedures described (physicochemical properties, identity of API) Quantitative determination of active, deviations, purity tests, pharmaceutical tests, colouring antimicrobial or chemical preservatives, results of validation studies, comments on the choice of routine tests and standards provided Copy of pharmacopoeia monograph and verification data Results of batch analysis (inc. date of manufacture, place of manufacture, batch size and use of batch tested) ... 

There is a wide range of chemicals suitable for antimicrobial application to fibre finishes. However, for practical reasons, amine-based chemicals, especially quaternary amines are used most because they can show multifunctionality as mentioned in Section 5.4.1. 

AI3-02258 EINECS 200-957-6 HSDB 5213 2-Methyl-2-nitropropanol 2-Methyl-2-nitropropan-1-ol 2-Methyl-2-nitro-1-propanol 2-Nitro-2-methyl-1-propanol 2-Nitro-2-methylpropanol NMP NMP Cone, NSC 17676 1-Propanol, 2-methyl-2-nltro-, Chemical and pharm-aceutioal intermediate, in tire cord adhesives, as formaldehyde release agents, deodorants, antimicrobials. Chemical intermediate, formaldehyde donor, textile reactant reduces formaldehyde on finished cloth. Solid mp = 89.5° bp ° = 94° Xm = 278 nm (MeOH) slightly soluble in H2O, soluble in organic solvents. Sigma-Aldrich Fine Chem. Whittaker dark Daniels. 

The use of antimicrobial finishes prevents the growth of microorganisms such as bacteria and fungi on the fibre/filter surface. These treatments include the application of halogens, alcohols, and metals, for example silver nitrate, to the filtration materials. Water-repellent finishes are also employed to form a barrier, which lowers the critical tension of the fibre surface. The repellency can be achieved by using chemical finishes, including chrome complexes, silicones, and fluorochemicals. 

When testing for the specific anti-microbial activity of an active substance, reference samples and control materials which have not been finished are necessary. They must be of the identical structure and chemical composition as the test material, but without the anti-microbial finish. When testing for the general antimicrobial activity at which all textile related activity affects the microorganisms, the reference samples mentioned above are not required instead, suitable positive growth controls which prove the biological operability of the test or test organisms are required. 

---