Anionic laundering

Antibacterial efficacy decreased after non-ionic and anionic lanndering of the fabric. In particular, the antibacterial activity of Ppy(Cl) samples was severely degraded by anionic laundering. The antibacterial activity of Ppy has been investigated against Streptococcus pneumoniae (RCMB 010010), Enterococcus faecalis (RCMB 010068) and Staphylococcus aureus (RCMB 010028), i.e.. Gram-positive bacteria. The agar disc diffusion method was used to determine the antibacterial activity and ampicillin... 

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. 

Peracetic acid or its anion, produced in situ from A, A, A, A -tetraacetylethylenediamine, in the presence of hydrogen peroxide, in slightly alkaline solution (equation 14), is an effective bleaching agent used in pulp manufacture and laundering. Household washing solution formulations contain perborate and activators that produce peracetic acid of bleaching effect . ... 

Surfactants, emulsifiers Dissolve lipids, disrupt membranes, denature proteins, and inactivate enzymes in high concentrations, and act as wetting agents Cationic detergents are used to sanitize utensils, anionic detergents are used to launder clothes and clean household objects, and quaternary ammonium compounds are sometimes used as an antiseptic on skin... 

Figure 3.2 shows typical cationic softener structures, for example, A,A-distearyl-A,iV-dimethyl ammonium chloride (DSDMAC). Cationic softeners have the best sofmess and are reasonably durable to laundering. They can be applied by exhaustion to all fibres from a high liquor to goods ratio bath and they provide a hydrophobic surface and poor rewetting properties, because their hydrophobic groups are oriented away from the fibre surface They are usually not compatible with anionic products (precipitation of insoluble adducts). 

Another flame-retardant treatment for wool based on exhanstion of an anionic species is the use of tetrabromophthalic anhydride, TBPA (Fig. 8.16), which hydrolyses to the carboxylic form during application. Use of TBPA at 10 % on weight of fabric under acid conditions provides effective flame retardancy that is dnrable to dry cleaning and mild laundering conditions (cold water washing at nentral pH). But TBPA is suspected to generate polybrominated dioxins under burning conditions. 

The important use of polyester fibers in clothing and bedding increased the nonionic constituent in laundering as it was found that nonionics remove soil from these fibers better than the anionics. 

The 1980s were rich in innovation. As cationic actives precipitate in the presence of anionic surfactants, thereby losing most of their efficacy, the anionic surfactant concentration in the liquor must be kept as low as possible. Therefore, the fabric softener had to be introduced in the last rinse of the wash cycle, when the detergent carryover is at a minimum. That represented a true constraint if the washer did not contain a dispenser for softener. The user had to stay near the washer to introduce the product at the beginning of the last rinse or had to run an extra rinse at the end of the laundering. 

Cationic actives interact with anionic fluorescent brighteners and reduce their whitening efficacy [2,26], Whether this is visually perceptible or not varies among reports. Crutcher et al. [32] and Wilson [33] conclude that, after a larger number of cumulative launderings, the loss is visually perceptible. On the contrary, Baumert and Cox Crews report that the decrease of whiteness index is significant, but not visually perceptible [34],... 

Nonionic and even anionic surfactants have also been added in small amounts to DHTDMAC to boost a product s softening efficacy. For example, it was shown in the late 1970s that the performance of a 6% DHTDMAC composition is matched by a mixture of 4.4% DHTDMAC and 0.6% anionic [56] 1.6% DHTDMAC could then be replaced by 0.6% anionic, which is less expensive. That was quite unexpected, as it was generally accepted that fabric softeners must be introduced in the last rinse of the laundering process to avoid their neutralization by the anionic detergent residues on the fabric, which causes the formation of insoluble species. 

The effect of changing the hydrophilic group from nonionic to anionic can be seen by comparing the soil removal properties of these same POE alcohols with two series of anionics made from the same hydrophobes, either by sulfating the alcohol mixture directly or after polyoxyethylenation with 3 or 6 mol of ethylene oxide. Using the same liquid no-phosphate formulation and the same laundering conditions at 49°C in 150 ppm hard water, the following results were obtained (Albin, 1973) ... 

RETENTION OF ANIONIC SURFACTANT FOLLOWING GARMENT LAUNDERING AND ITS POTENTIAL EFFECT ON DERMAimS SUFFERERS... 

Stein and Baumann studied the detergency of tallow SME and palm kernel SME [5]. The testing took place in a Launder-ometer at 90°C on cotton and at 60°C on a cotton/polyester blend. Water hardness was 300 ppm as CaCOj. They found that without a builder present, the tallow SME outperformed the palm kernel SME, which outperformed the LAS also included in the study. It was not until a nonionic surfactant and tripolyphosphate were added to the anionic surfactants that equivalent detergency was obtained. Stein and Baumann cite the low sensitivity to water hardness as the reason for the high detergency of the SMEs. 

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