Appearance of real linear polymer chains as recorded using an atomic force microscope on a surface, under liquid medium. Chain contour length for this polymer is ~204 nm; thickness is ~0.4 nm.[1]
IUPAC definition

A polymer is a substance composed of macromolecules.[2] A macromolecule is a molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass.[3]

A polymer (/ˈpɒlɪmər/;[4][5] Greek poly-, "many" + -mer, "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits.[6] Due to their broad spectrum of properties,[7] both synthetic and natural polymers play essential and ubiquitous roles in everyday life.[8] Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals.

The term "polymer" derives from the Greek word πολύς (polus, meaning "many, much") and μέρος (meros, meaning "part"). The term was coined in 1833 by Jöns Jacob Berzelius, though with a definition distinct from the modern IUPAC definition.[9][10] The modern concept of polymers as covalently bonded macromolecular structures was proposed in 1920 by Hermann Staudinger,[11] who spent the next decade finding experimental evidence for this hypothesis.[12]

Polymers are studied in the fields of polymer science (which includes polymer chemistry and polymer physics), biophysics and materials science and engineering. Historically, products arising from the linkage of repeating units by covalent chemical bonds have been the primary focus of polymer science. An emerging important area now focuses on supramolecular polymers formed by non-covalent links. Polyisoprene of latex rubber is an example of a natural polymer, and the polystyrene of styrofoam is an example of a synthetic polymer. In biological contexts, essentially all biological macromolecules—i.e., proteins (polyamides), nucleic acids (polynucleotides), and polysaccharides—are purely polymeric, or are composed in large part of polymeric components.

Cartoon schematic of polymer molecules
  1. ^ Roiter, Y.; Minko, S. (2005). "AFM Single Molecule Experiments at the Solid-Liquid Interface: In Situ Conformation of Adsorbed Flexible Polyelectrolyte Chains". Journal of the American Chemical Society. 127 (45): 15688–15689. doi:10.1021/ja0558239. PMID 16277495.
  2. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "polymer". doi:10.1351/goldbook.P04735
  3. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "macromolecule (polymer molecule)". doi:10.1351/goldbook.M03667
  4. ^ "Polymer – Definition of polymer". The Free Dictionary. Retrieved 23 July 2013.
  5. ^ "Define polymer". Dictionary Reference. Retrieved 23 July 2013.
  6. ^ "Polymer on Britannica".
  7. ^ Painter, Paul C.; Coleman, Michael M. (1997). Fundamentals of polymer science: an introductory text. Lancaster, Pa.: Technomic Pub. Co. p. 1. ISBN 978-1-56676-559-6.
  8. ^ McCrum, N. G.; Buckley, C. P.; Bucknall, C. B. (1997). Principles of polymer engineering. Oxford; New York: Oxford University Press. p. 1. ISBN 978-0-19-856526-0.
  9. ^ If two substances had molecular formulae such that one was an integer multiple of the other – e.g., acetylene (C2H2) and benzene (C6H6) – Berzelius called the multiple formula "polymeric". See: Jöns Jakob Berzelius (1833) "Isomerie, Unterscheidung von damit analogen Verhältnissen" (Isomeric, distinction from relations analogous to it), Jahres-Bericht über die Fortschitte der physischen Wissenschaften …, 12: 63–67. From page 64: "Um diese Art von Gleichheit in der Zusammensetzung, bei Ungleichheit in den Eigenschaften, bezeichnen zu können, möchte ich für diese Körper die Benennung polymerische (von πολυς mehrere) vorschlagen." (In order to be able to denote this type of similarity in composition [which is accompanied] by differences in properties, I would like to propose the designation "polymeric" (from πολυς, several) for these substances.)
    Originally published in 1832 in Swedish as: Jöns Jacob Berzelius (1832) "Isomeri, dess distinktion från dermed analoga förhållanden," Årsberättelse om Framstegen i Fysik och Kemi, pages 65–70; the word "polymeriska" appears on page 66.
  10. ^ Jensen, William B. (2008). "Ask the Historian: The origin of the polymer concept" (PDF). Journal of Chemical Education. 85 (5): 624–625. Bibcode:2008JChEd..85..624J. doi:10.1021/ed085p624. Archived from the original (PDF) on 2018-06-18. Retrieved 2013-03-04.
  11. ^ Staudinger, H (1920). "Über Polymerisation" [On polymerization]. Berichte der Deutschen Chemischen Gesellschaft (in German). 53 (6): 1073–1085. doi:10.1002/cber.19200530627.
  12. ^ Allcock, Harry R.; Lampe, Frederick W.; Mark, James E. (2003). Contemporary Polymer Chemistry (3 ed.). Pearson Education. p. 21. ISBN 978-0-13-065056-6.

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