Polycarboxylates are linear

polymer A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

s with a high

molecular mass The molecular mass (''m'') is the mass of a given molecule: it is measured in daltons (Da or u). Different molecules of the same compound may have different molecular masses because they contain different isotopes of an element. The related quanti ...

(M_r ≤ 100 000) and with many

carboxylate In organic chemistry, a carboxylate is the conjugate base of a carboxylic acid, (or ). It is an ion with negative charge. Carboxylate salts are salts that have the general formula , where M is a metal and ''n'' is 1, 2,...; ''carboxylat ...

groups. They are polymers of acrylic acid or

copolymers In polymer chemistry, a copolymer is a polymer derived from more than one species of monomer. The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained from the copolymerization of two monomer species are some ...

acrylic acid Acrylic acid (IUPAC: propenoic acid) is an organic compound with the formula CH2=CHCOOH. It is the simplest unsaturated carboxylic acid, consisting of a vinyl group connected directly to a carboxylic acid terminus. This colorless liquid has a ...

and

maleic acid Maleic acid or ''cis''-butenedioic acid is an organic compound that is a dicarboxylic acid, a molecule with two carboxyl groups. Its chemical formula is HO2CCH=CHCO2H. Maleic acid is the ''cis''-isomer of butenedioic acid, whereas fumaric ac ...

. The

is used as the

sodium salt Sodium salts are salt (chemistry), salts composed of a sodium cation and the conjugate base anion of some Inorganic compound, inorganic or Organic compound, organic acids. They can be formed by the Neutralization (chemistry), neutralization of su ...

(see:

sodium polyacrylate Sodium polyacrylate (ACR, ASAP, or PAAS), also known as waterlock, is a sodium salt of polyacrylic acid with the chemical formula ��CH2−CH(CO2Na)−sub>n and has broad applications in consumer products. This super-absorbent polymer (SAP) has ...

Use

Polycarboxylates are used as

builders Builder may refer to: * Construction worker, who specializes in building work * Carpenter, a skilled craftsman who works with wood * General contractor, that specializes in building work ** Subcontractor * Builder (detergent), a component of mode ...

in detergents. Their high

chelating Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a Denticity, polydentate (multiple bonded) ligand and a single central metal atom. These l ...

power, even at low concentrations, reduces

deposits A deposit account is a bank account maintained by a financial institution in which a customer can deposit and withdraw money. Deposit accounts can be savings accounts, Transaction account#Current accounts, current accounts or any of several othe ...

on the laundry and inhibits the crystal growth of

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

. Polycarboxylate ethers (PCE) are used as

superplasticizer Superplasticizers (SPs), also known as high range water reducers, are additives used in making high strength concrete. Plasticizers are chemical compounds that enable the production of concrete with approximately 15% less water content. Superplast ...

s in concrete production.

Safety

Polycarboxylates are poorly

biodegradable Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradati ...

but have a low

ecotoxicity Ecotoxicity, the subject of study in the field of ecotoxicology (a portmanteau of ecology and toxicology), refers to the biological, chemical or physical stressors that affect ecosystems. Such stressors could occur in the natural environment at ...

. In the

sewage treatment plant Sewage treatment (or domestic wastewater treatment, municipal wastewater treatment) is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding envir ...

, the polymer remains largely in the sludge and is separated from the

wastewater Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industr ...

. Polyamino acids like

polyaspartic acid Polyaspartic acid (PASA) is a biodegradable, water-soluble condensation polymer based on the amino acid aspartic acid. It is a biodegradable replacement for water softeners and related applications. PASA can be chemically crosslinked with a wid ...

and

polyglutamic acid Polyglutamic acid (PGA) is a polymer of the amino acid glutamic acid (GA). Gamma PGA (Poly-γ-glutamic acid, γ-PGA) - the form where the peptide bonds are between the amino group of GA and the carboxyl group at the end of the GA side chain - i ...

have better

biodegradability Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradati ...

but lower chelating performance than polyacrylates. They are also less stable towards heat and alkali. Since they contain nitrogen, they contribute to

eutrophication Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...

References

{{reflist Polymers Salts and esters of carboxylic acids