Polymer backbone

IUPAC definition

Main chain or Backbone
That linear chain to which all other chains, long or short or both,
may be regarded as being pendant.

Note: Where two or more chains
could equally be considered to be the main chain, that one is
selected which leads to the simplest representation of the
molecule.[1]

In polymer science, the polymer chain or simply backbone of a polymer is the main chain of a polymer. Polymers are often classified according to the elements in the main chains. The character of the backbone, i.e. its flexibility, determines the properties of the polymer (such as the glass transition temperature). For example, in polysiloxanes (silicone), the backbone chain is very flexible, which results in a very low glass transition temperature of −123 °C (−189 °F; 150 K).[2] The polymers with rigid backbones are prone to crystallization (e.g. polythiophenes) in thin films and in solution. Crystallization in its turn affects the optical properties of the polymers, its optical band gap and electronic levels.[3]

  1. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "main chain (backbone) of a polymer". doi:10.1351/goldbook.M03694
  2. ^ "Polymers". Archived from the original on 2015-10-02. Retrieved 2015-09-17.
  3. ^ Brabec, C.J.; Winder, C.; Scharber, M.C; Sarıçiftçi, S.N.; Hummelen, J.C.; Svensson, M.; Andersson, M.R. (2001). "Influence of disorder on the photoinduced excitations in phenyl substituted polythiophenes" (PDF). Journal of Chemical Physics. 115 (15): 7235. Bibcode:2001JChPh.115.7235B. doi:10.1063/1.1404984.