Builders, detergent polycarboxylates

Concerns about the effect of TPP on eutrophication have led many states, cities, and regional governments to ban the use of the compound in syndets. Such bans have caused serious problems for detergent manufacturers, however, because no entirely satisfactory substitute for TPP has yet been found. Two promising candidates are the sodium salt of nitrilotriacetic acid, 3Na, N(CH2C02)3 , or NTA and ethylenediaminetetraacetic acid (EDTA). Both of these compounds act in much the same way as TPP, that is, by sequestering metal ions. Other builders that have been incorporated into syndet formulations include sodium carbonate, synthetic zeolites, borates, and organic polymers known as polycarboxylates. 

Co-builders such as nitrilotriacetic acid or polycarboxylates also may be incorporated into the detergent formulation. Wash performance of detergents decreases with increasing calcium concentration. Protease performance varies, but high calcium concentrations tend to reduce protease performance. Therefore it is an advantage to add a builder system to the detergent. Proteases need a small amount of calcium for the sake of stability, but even with the most efficient builder systems, stability during wash is not a problem. 

Interest in detergent products derived from renewable resources and with better biodegradability has driven evaluation of oxidized sugars and starches as builders or co-builders in detergents.113 Builders and co-builders complex calcium and magnesium ions in hard water to prevent sealing or deposits due to precipitation of insoluble carbonate salts. In current powder detergents, the builders are usually zeolites used in combination with polycarboxylate polymers derived from synthetic acrylic-maleic acid copolymers.114... 

Polymeric polycarboxylates, such as polyacrylates and acrylate-maleate copolymers, are finding usage as cobuilders in zeolite-carbonate builder systems. Polymers are finding increasing application in detergent formulations as dispersing... 

Polycarboxylates Carboxylate derivatives of poly(vinyl alcohol) are biodegradable and functional in detergents as co-builders, although too costly to be practical replacements for polyacrylic acid at this time. Matsumura et al. polymerized vinyloxyacetic acid [69, 70] and Lever has patented polymers based on vinyl carbamates obtained from the reaction of vinyl chloroformates and amino acids such as aspartic and glutamic acids [71]. Both hydrolyze (Scheme 4), to polyvinyl alcohol, which is biodegradable. 

Production of Detergent Builders Phosphates, Carbonates, and Polycarboxylates... 

Sodium carbonate or soda ash is incorporated as an ingredient in detergents to fnnction as an inexpensive builder as well as provide the alkalinity desired in the washing solution. The soda ash removes calcium from hard water in the form of precipitated calcium carbonate and magnesium carbonate. These precipitates can cause incrustations on fabrics and washing machines. However, these incrustations can be minimized by the use of polycarboxylates as dispersants in the detergent formulation [16]. Soda ash can also be used in combination with other builders such as zeolites and silicates in the detergent formulation. 

Polycarboxylates, also known as polyacrylates, are polymers having a carbon-carbon backbone with attached carboxyl groups. In household consumer products, the anionic polycarboxylates most commonly used are copolymers of acrylic acid and maleic anhydride, copolymers of acrylic acid and methacrylic acid, or polymers of acrylic acid. Polycarboxylates find use as detergent builders and as partial replacements for polyphosphates. However, they are very expensive for use in high concentrations as builders in detergent formulations and also have poor biodegradability [16]. 

The polycarboxylate builders inhibit the growth of inorganic crystals, which would be formed in their absence during the washing process when phosphate-free or low-phosphate detergents are used. Another function of the polycarboxylates is their ability to disperse soil as well as prevent redeposition of the soil and minimize incrustations of insoluble salts on the fabric. Polycarboxylates are also used as dispersants and to provide shine in formulations for automatic dishwashing machines. 

This interesting reaction has been reviewed.As is evident, maleates or fumarates can be employed as starting material and in many cases high yields of the product could be obtained. Due to the nature of the functional anion needed, the final product is usually highly functionalized. For instance, malonic acid or acetoacetic acid esters give rise to polycarboxylic acids 84 and 85. These could be potentially useful as detergent builders. Polycarboxy functions are also useful for resins such as in the curing of epoxies. 

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