The Role of Polymers in Laundry Detergents
Today’s laundry detergents rely on a long list of ingredients to serve varying purposes: surfactants, builders, sequestrants, dispersants, enzymes, and more. A multifunctional ingredient like a polymer can therefore be a powerful ally, streamlining and simplifying formulations by serving multiple roles at once.
The role of polymers in detergents is a little bit “jack-of-all-trades”. A good polymer offers sequestrant support and boosts the effectiveness of other ingredients thereby keeping minerals dispersed in washing liquid.
The Perfect Polymer Is Multi-Purpose & Biodegradable
Polynil HP (Sodium polyacrylate) and Polynil CP (Maleic Acrylic Copolymer) play multiple roles and contribute to formulating a successful detergent. These substances are known as effective dispersing and chelating agents, preventing the redeposition of stains on fabrics. They are biodegradable, non-toxic, and can be used in aquatic systems. Additionally, these materials exhibit excellent thermal and chemical stability, which enhances the shelf life and performance of products.
History of Polymers:
In the early days, polymers have found very little value in detergent and cleaning formulations. Phosphate compounds such as sodium triphosphate (STP) and sodium/potassium phosphate were used primarily in detergent formulations in which they comprise them up to 50 % by weight. STP provides significant contributions to laundering by performing several crucial functions. It forms complexes with polyvalent cations such as Ca2+ and Mg2+ ions and as a result water hardness is reduced, thereby boosting the performance of the surfactants. STP also aids in removing, dispersing and suspending the dirt released and ensuring a good powder structure. However, over the years, phosphates were found to stimulate the rapid growth of algae and plants in lakes and other bodies of water, which caused the deterioration of water quality and the recreational value of the lakes. Due to environmental concerns and government regulations and restrictions regarding the use of phosphates, formulators pursued to reinvent the detergent compositions. Decades of efforts and millions of dollars were spent to find safe, high-performing and economical substitutes for phosphates. Some of the potential alternatives that came out of the market include systems that are based on nitrilotriacetate (NTA), sodium citrates and zeolites.
NTA exhibits good cleaning and chelating properties but was later on suspended by National Institute of Environmental Health and Sciences (NIEHS) because it poses detrimental health threats to the development of embryo or what is known as teratogenic effect especially when combined with heavy metals such as cadmium and mercury. Sodium citrate, on the other hand, is environmentally safe and is compatible with cleaning formulations because of its solubility properties. However, in terms of cost and effectiveness, it is generally inferior compared to STP. In cases where water contains elevated amount of these ions, the zeolite system requires a co-builder, which is water soluble.
Polycarboxylates have proven to be the most effective additives for this system. Their function, however, is not via complexation with the hard ions in water, but they aid in the dispersion of calcium salts such as calcium carbonate or phosphate and the soil particulates released during washing. Because these polymeric materials are available at reasonable costs and possess unique and varied multifunctionality, formulators and polymer chemists were prompted to investigate beyond polycarboxylates.
The applications of polymers in household cleaning compositions, both natural and synthetic, have grown tremendously. They have been an important part of detergent formulations for many years now, and 90 % of the polymers used belong to a class of polycarboxylates. The major polycarboxylates used in cleaning products are homopolymers derived from acrylic acid (PAA) and copolymer of acrylic/maleic acid (PAA/MA). They are generally used as sodium salts in phosphate-free detergents to prevent soil redeposition and encrustation.
The Perfect Polymer Is Multi-Purpose & Biodegradable
Polynil HP (Sodium polyacrylate) and Polynil CP (Maleic Acrylic Copolymer) play multiple roles and contribute to formulating a successful detergent. These substances are known as effective dispersing and chelating agents, preventing the redeposition of stains on fabrics. They are biodegradable, non-toxic, and can be used in aquatic systems. Additionally, these materials exhibit excellent thermal and chemical stability, which enhances the shelf life and performance of products.
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