Polyacrylic acid

Last updated
Poly(acrylic acid)
Polyacrylic acid.svg
Names
IUPAC name
Poly(acrylic acid), poly(1-carboxyethylene)
Other names
PAA, PAAc, Acrysol, Acumer, Alcosperse, Aquatreat, Carbomer, Sokalan
Identifiers
ChEBI
ChemSpider
  • none
ECHA InfoCard 100.115.375 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 618-347-7
KEGG
UNII
Properties
(C3H4O2)n
Molar mass variable
log P 0.25700 [1]
Hazards [2]
GHS labelling:
GHS-pictogram-exclam.svg
Warning
H315, H319, H335
NFPA 704 (fire diamond)
NFPA 704.svgHealth 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
0
0
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Poly(acrylic acid) (PAA; trade name Carbomer) is a polymer with the formula (CH2-CHCO2H)n. It is a derivative of acrylic acid (CH2=CHCO2H). In addition to the homopolymers, a variety of copolymers and crosslinked polymers, and partially deprotonated derivatives thereof are known and of commercial value. In a water solution at neutral pH, PAA is an anionic polymer, i.e., many of the side chains of PAA lose their protons and acquire a negative charge. Partially or wholly deprotonated PAAs are polyelectrolytes, with the ability to absorb and retain water and swell to many times their original volume. These properties – acid-base and water-attracting – are the bases of many applications.

Contents

Synthesis

PAA, like any acrylate polymer, is usually synthesized through a process known as free radical polymerization, [3] [4] though graft polymerization may also be used. [5] [6] Free radical polymerization involves the conversion of monomers, in this case, acrylic acid (CH2=CHCO2H), into a polymer chain through the action of free radicals. [7] [8] [9] The process typically follows these steps: [10]

  1. Initiation: Free radicals are generated by initiators such as potassium persulfate (K2 S2O8) or Azobisisobutyronitrile (AIBN). These radicals are highly reactive and can start the polymerization process by reacting with the monomer units. [11]
  2. Propagation: Once the radical reacts with a monomer, it creates a new radical at the end of the growing chain. This new radical can react with additional monomer units, allowing the chain to grow. [12]
  3. Termination: The reaction continues until two radicals recombine, or a radical is transferred to another molecule, terminating the growth of the polymer chain. [13]
  4. Chain transfer and Inhibition: Other reactions can also occur, such as chain transfer (where the radical is transferred to a different molecule, creating a new radical) or inhibition (where impurities stop the growth of the chain). [14]

Production

The global market is estimated to be worth $3.4 billion in 2022. [15] [16]

Structure and derivatives

Polyacrylic acid is a weak anionic polyelectrolyte, whose degree of ionisation is dependent on solution pH. In its non-ionised form at low pHs, PAA may associate with various non-ionic polymers (such as polyethylene oxide, poly-N-vinyl pyrrolidone, polyacrylamide, and some cellulose ethers) and form hydrogen-bonded interpolymer complexes. [17] In aqueous solutions PAA can also form polycomplexes with oppositely charged polymers such as chitosan, surfactants, and drug molecules (for example, streptomycin). [18]

Physical properties

Dry PAAs are sold as white, fluffy powders.

Derivatives

In the dry powder form of Sodium Polyacrylate, the positively charged sodium ions are bound to the polyacrylate, however in aqueous solutions the sodium ions can dissociate. The presence of sodium cations allows the polymer to absorb a high amount of water.

Applications

Absorbent

PAA is widely used in dispersants. Its molecular weight has a significant impact on the rheological properties and dispersion capacity, and hence applications. The dominant application for PAA is as a superabsorbent. About 25% of PAA is used for detergents and dispersants.

Polyacrylic acid and its derivatives (particularly sodium polyacrylate) are used in disposable diapers. Acrylic acid is also the main component of Superabsorbent Polymers (SAPs), which are cross-linked polyacrylates that can absorb and retain more than 100 times of their own weight in liquid. The US Food and Drug Administration authorised the use of SAPs in packaging with indirect food contact. [19] [20]

Cleaning

Detergents often contain copolymers of acrylic acid that assist in sequestering dirt. Cross-linked polyacrylic acid has also been used in the production of household products, including floor cleaners. PAA may inactivate the antiseptic chlorhexidine gluconate. [21]

Biocompatible materials

The neutralized polyacrylic acid gels are suitable biocompatible matrices for medical applications such as gels for skin care products. PAA films can be deposited on orthopaedic implants to protect them from corrosion. Crosslinked hydrogels of PAA and gelatin have also been used as medical glue.

Paints and cosmetics

Other applications involve paints and cosmetics. They stabilize suspended solid in liquids, [22] prevent emulsions from separating, and control the consistency in flow of cosmetics. Carbomer codes (910, 934, 940, 941, and 934P) are an indication of molecular weight and the specific components of the polymer. For many applications PAAs are used in form of alkali metal or ammonium salts, e.g. sodium polyacrylate.

Emerging applications

Hydrogels derived from PAA have attracted much study for use as bandages and aids for wound healing. [23]

Drilling fluid and metal quenching

A few reports were made on PAA use as deflocculant (so called alkaline polyacrylates) for oil drilling industry. [24] [25]

It was also reported to be used for metal quenching in metalworking (see Sodium polyacrylate). [26]

Related Research Articles

Acrylates are the salts, esters, and conjugate bases of acrylic acid. The acrylate ion is the anion CH2=CHCO−2. Often, acrylate refers to esters of acrylic acid, the most common member being methyl acrylate. These acrylates contain vinyl groups. These compounds are of interest because they are bifunctional: the vinyl group is susceptible to polymerization and the carboxylate group carries myriad functionalities.

<span class="mw-page-title-main">Polyacrylamide</span> Chemical compound

Polyacrylamide (abbreviated as PAM or pAAM) is a polymer with the formula (-CH2CHCONH2-). It has a linear-chain structure. PAM is highly water-absorbent, forming a soft gel when hydrated. In 2008, an estimated 750,000,000 kg were produced, mainly for water treatment and the paper and mineral industries.

<span class="mw-page-title-main">Acrylic acid</span> Chemical compound

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 characteristic acrid or tart smell. It is miscible with water, alcohols, ethers, and chloroform. More than a million tons are produced annually.

<span class="mw-page-title-main">Polyelectrolyte</span> Polymers whose repeating units bear an electrolyte group

Polyelectrolytes are polymers whose repeating units bear an electrolyte group. Polycations and polyanions are polyelectrolytes. These groups dissociate in aqueous solutions (water), making the polymers charged. Polyelectrolyte properties are thus similar to both electrolytes (salts) and polymers and are sometimes called polysalts. Like salts, their solutions are electrically conductive. Like polymers, their solutions are often viscous. Charged molecular chains, commonly present in soft matter systems, play a fundamental role in determining structure, stability and the interactions of various molecular assemblies. Theoretical approaches to describing their statistical properties differ profoundly from those of their electrically neutral counterparts, while technological and industrial fields exploit their unique properties. Many biological molecules are polyelectrolytes. For instance, polypeptides, glycosaminoglycans, and DNA are polyelectrolytes. Both natural and synthetic polyelectrolytes are used in a variety of industries.

<span class="mw-page-title-main">Sodium polyacrylate</span> Anionic polyelectrolyte polymer

Sodium polyacrylate (ACR, ASAP, or PAAS), also known as waterlock, is a sodium salt of polyacrylic acid with the chemical formula [−CH2−CH(CO2Na)−]n and has broad applications in consumer products. This super-absorbent polymer (SAP) has the ability to absorb 100 to 1000 times its mass in water. Sodium polyacrylate is an anionic polyelectrolyte with negatively charged carboxylic groups in the main chain. It is a polymer made up of chains of acrylate compounds. It contains sodium, which gives it the ability to absorb large amounts of water. When dissolved in water, it forms a thick and transparent solution due to the ionic interactions of the molecules. Sodium polyacrylate has many favorable mechanical properties. Some of these advantages include good mechanical stability, high heat resistance, and strong hydration. It has been used as an additive for food products including bread, juice, and ice cream.

<span class="mw-page-title-main">Acrylate polymer</span> Group of polymers prepared from acrylate monomers

An acrylate polymer is any of a group of polymers prepared from acrylate monomers. These plastics are noted for their transparency, resistance to breakage, and elasticity.

<span class="mw-page-title-main">Superabsorbent polymer</span> Polymers that can absorb and retain extremely large amounts of a liquid relative to their own mass

A superabsorbent polymer (SAP) (also called slush powder) is a water-absorbing hydrophilic homopolymers or copolymers that can absorb and retain extremely large amounts of a liquid relative to its own mass.

Solution polymerization is a method of industrial polymerization. In this procedure, a monomer is dissolved in a non-reactive solvent that contains a catalyst or initiator.

Poly(N-isopropylacrylamide) (variously abbreviated PNIPA, PNIPAM, PNIPAAm, NIPA, PNIPAA or PNIPAm) is a temperature-responsive polymer that was first synthesized in the 1950s. It can be synthesized from N-isopropylacrylamide which is commercially available. It is synthesized via free-radical polymerization and is readily functionalized making it useful in a variety of applications.

<span class="mw-page-title-main">Temperature-responsive polymer</span> Polymer showing drastic changes in physical properties with temperature

Temperature-responsive polymers or thermoresponsive polymers are polymers that exhibit drastic and discontinuous changes in their physical properties with temperature. The term is commonly used when the property concerned is solubility in a given solvent, but it may also be used when other properties are affected. Thermoresponsive polymers belong to the class of stimuli-responsive materials, in contrast to temperature-sensitive materials, which change their properties continuously with environmental conditions. In a stricter sense, thermoresponsive polymers display a miscibility gap in their temperature-composition diagram. Depending on whether the miscibility gap is found at high or low temperatures, either an upper critical solution temperature (UCST) or a lower critical solution temperature (LCST) exists.

<i>N</i>,<i>N</i>-Methylenebisacrylamide Chemical compound, polyacrylamide crosslinker

N,N′-Methylenebisacrylamide (MBAm or MBAA, colloquially "bis") is the organic compound with the formula CH2[NHC(O)CH=CH2]2. A colorless solid, this compound is a crosslinking agent in polyacrylamides, e.g., as used for SDS-PAGE.

<span class="mw-page-title-main">2-Acrylamido-2-methylpropane sulfonic acid</span> Chemical compound

2-Acrylamido-2-methylpropane sulfonic acid (AMPS) was a Trademark name by The Lubrizol Corporation. It is a reactive, hydrophilic, sulfonic acid acrylic monomer used to alter the chemical properties of wide variety of anionic polymers. In the 1970s, the earliest patents using this monomer were filed for acrylic fiber manufacturing. Today, there are over several thousands patents and publications involving use of AMPS in many areas including water treatment, oil field, construction chemicals, hydrogels for medical applications, personal care products, emulsion coatings, adhesives, and rheology modifiers.

<span class="mw-page-title-main">Poly(methacrylic acid)</span> Chemical compound

Poly(methacrylic acid) (PMAA) is a polymer made from methacrylic acid (preferred IUPAC name, 2-methylprop-2-enoic acid), which is a carboxylic acid. It is often available as its sodium salt, poly(methacrylic acid) sodium salt. The monomer is a viscous liquid with a pungent odour. The first polymeric form of methacrylic acid was described in 1880 by Engelhorn and Fittig. The use of high purity monomers is required for proper polymerization conditions and therefore it is necessary to remove any inhibitors by extraction (phenolic inhibitors) or via distillation. To prevent inhibition by dissolved oxygen, monomers should be carefully degassed prior to the start of the polymerization.

<span class="mw-page-title-main">Polyaspartic acid</span> Chemical compound

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 wide variety of methods to yield PASA hydrogels. The resulting hydrogels are pH-sensitive such that under acidic conditions, they shrink, while the swelling capacity increases under alkaline conditions.

<span class="mw-page-title-main">Vinylsulfonic acid</span> Chemical compound

Vinylsulfonic acid is the organosulfur compound with the chemical formula CH2=CHSO3H. It is the simplest unsaturated sulfonic acid. The C=C double bond is a site of high reactivity. Polymerization gives polyvinylsulfonic acid, especially when used as a comonomer with functionalized vinyl and (meth)acrylic acid compounds. It is a colorless, water-soluble liquid, although commercial samples can appear yellow or even red.

Common hydrogel agriculture's ingredient is potassium polyacrylate or sodium polyacrylate. As a superabsorbent material, it can absorb plenty of water and turn water to gel to store water.

1-Vinylimidazole is a water-soluble basic monomer that forms quaternizable homopolymers by free-radical polymerization with a variety of vinyl and acrylic monomers. The products are functional copolymers, which are used as oil field chemicals and as cosmetic auxiliaries. 1-Vinylimidazole acts as a reactive diluent in UV lacquers, inks, and adhesives.

<span class="mw-page-title-main">Potassium polyacrylate</span> Chemical compound

Potassium polyacrylate is a potassium salt of polyacrylic acid with the chemical formula [−CH2−CH(CO2K)−]n. As a type of superabsorbent polymer, it can absorb hundreds of times its original weight in purified water.

Polysuccinimide (PSI), also known as polyanhydroaspartic acid or polyaspartimide, is formed during the thermal polycondensation of aspartic acid and is the simplest polyimide. Polysuccinimide is insoluble in water, but soluble in some aprotic dipolar solvents. Its reactive nature makes polysuccinimide a versatile starting material for functional polymers made from renewable resources.

Chitosan-poly is a composite that has been increasingly used to create chitosan-poly(acrylic acid) nanoparticles. More recently, various composite forms have come out with poly(acrylic acid) being synthesized with chitosan which is often used in a variety of drug delivery processes. Chitosan which already features strong biodegradability and biocompatibility nature can be merged with polyacrylic acid to create hybrid nanoparticles that allow for greater adhesion qualities as well as promote the biocompatibility and homeostasis nature of chitosan poly(acrylic acid) complex. The synthesis of this material is essential in various applications and can allow for the creation of nanoparticles to facilitate a variety of dispersal and release behaviors and its ability to encapsulate a multitude of various drugs and particles.

References

  1. ↑ "Polyacrylic acid_msds". Archived from the original on 2022-02-21. Retrieved 2018-04-23.
  2. ↑ "C&L Inventory". echa.europa.eu. Archived from the original on 2021-04-05. Retrieved 2021-12-05.
  3. ↑ Zhang, Rongguo; Li, Qiong; Zhang, Anfu; Liu, Yong; Lei, Jiaheng (2008-12-01). "The synthesis technique of polyacrylic acid superplasticizer". Journal of Wuhan University of Technology-Mater. Sci. Ed. 23 (6): 830–833. doi:10.1007/s11595-008-6830-y. ISSN   1993-0437.
  4. ↑ Hu, Yong; Jiang, Xiqun; Ding, Yin; Ge, Haixiong; Yuan, Yuyan; Yang, Changzheng (2002-08-01). "Synthesis and characterization of chitosan–poly(acrylic acid) nanoparticles". Biomaterials. 23 (15): 3193–3201. doi:10.1016/S0142-9612(02)00071-6. ISSN   0142-9612.
  5. ↑ Li, An; Wang, Aiqin; Chen, Jianmin (2004-05-05). "Studies on poly(acrylic acid)/attapulgite superabsorbent composite. I. Synthesis and characterization". Journal of Applied Polymer Science. 92 (3): 1596–1603. doi:10.1002/app.20104. ISSN   0021-8995.
  6. ↑ Lin, Jianming; Wu, Jihuai; Yang, Zhengfang; Pu, Minli (2001-03-01). "Synthesis and Properties of Poly(acrylic acid)/Mica Superabsorbent Nanocomposite". Macromolecular Rapid Communications. 22 (6): 422–424. doi:10.1002/1521-3927(20010301)22:6<422::AID-MARC422>3.0.CO;2-R. ISSN   1022-1336.
  7. ↑ Bromberg, Lev E.; Barr, David P. (1999-06-01). "Aggregation Phenomena in Aqueous Solutions of Hydrophobically Modified Polyelectrolytes. A Probe Solubilization Study". Macromolecules. 32 (11): 3649–3657. doi:10.1021/ma981946k. ISSN   0024-9297.
  8. ↑ Laschewsky, André; Herfurth, Christoph; Miasnikova, Anna; Stahlhut, Frank; Weiss, Jan; Wieland, Christoph; Wischerhoff, Erik; Gradzielski, Michael; Malo de Molina, Paula (January 2003), Patil, Anjali; Ferritto, Michael S. (eds.), "Stars and Blocks: Tailoring Polymeric Rheology Modifiers for Aqueous Media by Controlled Free Radical Polymerization", ACS Symposium Series, Washington, DC: American Chemical Society, vol. 1148, pp. 125–143, doi:10.1021/bk-2013-1148.ch008, ISBN   978-0-8412-2905-1 , retrieved 2023-12-20
  9. ↑ Iqbal, Hafiz M. N.; Rasheed, Tahir; Bilal, Muhammad (2018-10-03), Ahmed, Shakeel; Hussain, Chaudhery Mustansar (eds.), "Design and Processing Aspects of Polymer and Composite Materials", Green and Sustainable Advanced Materials (1 ed.), Wiley, pp. 155–189, doi:10.1002/9781119407089.ch7, ISBN   978-1-119-40708-9 , retrieved 2023-12-20
  10. ↑ Liu, Ke; Corrigan, Nathaniel; Postma, Almar; Moad, Graeme; Boyer, Cyrille (2020-10-27). "A Comprehensive Platform for the Design and Synthesis of Polymer Molecular Weight Distributions". Macromolecules. 53 (20): 8867–8882. doi:10.1021/acs.macromol.0c01954. ISSN   0024-9297.
  11. ↑ Plamper, Felix A.; Becker, Harald; Lanzendörfer, Michael; Patel, Mushtaq; Wittemann, Alexander; Ballauff, Matthias; Müller, Axel H. E. (2005-09-23). "Synthesis, Characterization and Behavior in Aqueous Solution of Star‐Shaped Poly(acrylic acid)". Macromolecular Chemistry and Physics. 206 (18): 1813–1825. doi:10.1002/macp.200500238. ISSN   1022-1352.
  12. ↑ Cuti, Sergio S.; Henton, David E.; Powell, Cynthia; Reim, Robert E.; Smith, Patrick; Staples, Thomas L. (1997-04-18). "The effects of MEHQ on the polymerization of acrylic acid in the preparation of superabsorbent gels". Journal of Applied Polymer Science. 64 (3): 577–589. doi:10.1002/(SICI)1097-4628(19970418)64:3<577::AID-APP14>3.0.CO;2-V. ISSN   0021-8995.
  13. ↑ Luciani, Carla; Choi, Kyu Yong (September 2023). "Modelling of a continuous kneader reactor for the polymerization of partially neutralized acrylic acid". The Canadian Journal of Chemical Engineering. 101 (9): 5151–5161. doi:10.1002/cjce.24898. ISSN   0008-4034.
  14. ↑ Nicolaÿ, Renaud; Mosnáček, Jaroslav; Kar, Kishore K.; Fruchey, Stanley O.; Cloeter, Michael D.; Harner, Richard S.; Matyjaszewski, Krzysztof (2012-03-28). "Efficient Polymerization Inhibition Systems for Acrylic Acid Distillation: Vapor-Phase Inhibitors". Industrial & Engineering Chemistry Research. 51 (12): 4467–4471. doi:10.1021/ie201709y. ISSN   0888-5885.
  15. ↑ "Polyacrylic Acid Market Demand, Key Players, Opportunities, & Forecast Analysis By 2029". www.databridgemarketresearch.com. Retrieved 2023-12-20.
  16. ↑ ltd, Research and Markets. "Polyacrylic Acid - Global Strategic Business Report". www.researchandmarkets.com. Retrieved 2023-12-20.
  17. ↑ Khutoryanskiy, Vitaliy V.; Staikos, Georgios (9 March 2009). Hydrogen-bonded Interpolymer Complexes: Formation, Structure And Applications. World Scientific. ISBN   978-981-4475-04-4. OCLC   1200871469. Archived from the original on 2022-02-21. Retrieved 2022-02-21.
  18. ↑ Nurkeeva, Zauresh S; Khutoryanskiy, Vitaliy V; Mun, Grigoriy A; Sherbakova, Marina V; Ivaschenko, Anatoliy T; Aitkhozhina, Nazira A (March 2004). "Polycomplexes of poly(acrylic acid) with streptomycin sulfate and their antibacterial activity". European Journal of Pharmaceutics and Biopharmaceutics. 57 (2): 245–9. doi:10.1016/S0939-6411(03)00149-8. PMID   15018981. Archived from the original on 21 February 2022 – via PubMed, Elsevier.
  19. ↑ Orwoll, Robert A.; Yong, Chong S. (1999). "Poly(acrylic acid)". In Mark, James E. (ed.). Polymer Data Handbook. Oxford University Press, Inc. pp. 252–253. ISBN   978-0195107890. OCLC   39962426. Archived from the original on 2022-02-21. Retrieved 2022-02-21.
  20. ↑ "Acrylates". The Macrogalleria. Polymer Science Learning Center. 2005. Archived from the original on 21 February 2022. Retrieved 25 June 2015.
  21. ↑ Kaiser, Nancy; Klein, Dan; Karanja, Peter; Greten, Zachariah; Newman, Jerry (2009). "Inactivation of chlorhexidine gluconate on skin by incompatible alcohol hand sanitizing gels". American Journal of Infection Control. 37 (7): 569–73. doi:10.1016/j.ajic.2008.12.008. PMID   19398245. Archived from the original on 19 December 2021 – via PubMed, Elsevier.
  22. ↑ Kuila, Debasish; Blay, George A.; Borjas, Ricardo E.; Hughes, Steve; Maddox, Phil; Rice, Kay; Stansbury, Wayne; Laurel, Norma (1999-08-15). "Polyacrylic acid (poly-A) as a chelant and dispersant". Journal of Applied Polymer Science. 73 (7): 1097–1115. doi:10.1002/(SICI)1097-4628(19990815)73:7<1097::AID-APP2>3.0.CO;2-F. ISSN   0021-8995.
  23. ↑ Mogoşanu, George Dan; Grumezescu, Alexandru Mihai (25 March 2014). "Natural and synthetic polymers for wounds and burns dressing". International Journal of Pharmaceutics. 463 (2): 127–136. doi:10.1016/j.ijpharm.2013.12.015. PMID   24368109. Archived from the original on 1 February 2022.
  24. ↑ "Deflocculants: A Detailed Overview". Archived from the original on February 26, 2021.
  25. ↑ Petrov, N.A.; Maikobi, A.A. (December 2017). "Investigation of Uniflox Reagent for Drilling Siberian Solvent Solutions". Oil and Gas Business (6): 6–19. doi:10.17122/ogbus-2017-6-6-19.
  26. ↑ Griffiths, W. D. (1989). The quenching characteristics of sodium polyacrylate solutions (doctoral thesis). Sheffield: Sheffield Hallam University.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.