Project Details Terminology for Chain Polymerization

Project No.: 
Start Date: 
01 May 2010
End Date: 
Division Name: 


To propose and disseminate throughout the scientific community authoritative guidelines for describing chain polymerization which are consistent with current IUPAC documents.


During the last decades, a sometimes conflicting and contradictory terminology for describing chain polymerization processes has developed. IUPAC has recently addressed this problem for the case of radical polymerizations which derive some of the characteristics of living polymerization from the presence of a reversible deactivation mechanism (Pure Appl. Chem. 2010, Vol. 82, No. 2, pp. 483-491, doi:10.1351/PAC-REP-08-04-03). However, the issues are more pervasive and extend beyond the confines of radical polymerization, such that there is now an evident need to address the development of an even wider terminology that is being applied across all polymerization processes, often leading to conflicts of understanding at the boundaries of chain polymerization, addition polymerization and condensation polymerization.

This project will undertake to review current terminology for chain polymerization processes in the light of current IUPAC recommendations and recent developments in what continues to be a very rapidly developing field.

This project will result in the preparation of a comprehensive document which will:

  • provide definitions of the relevant important terminology;
  • be a basic guide to terminology of mechanisms of chain polymerization processes;
  • highlight common misunderstandings evident in the prior literature;
  • remove inconsistencies in recommendations which have been published at different times;
  • where possible provide a concordance of formerly used terms and descriptors and classify these either as preferred, acceptable or not acceptable.


July 2010 – project announcement published in Chem. Int. Jul-Aug, p. 24

March 2014 update – The task group has considered terminology relating to radical (issues not resolved previously), cationic, anionic, catalyst transfer polymerization; that section is complete and publication is in preparation. The systems not fully dealt with include coordination and related polymerizations.

June 2017 update – A draft document has been produced. Two significant issues have been identified.
The document is deficient or uneven in its coverage of some forms of chain polymerization, in particular, those outside of the field of expertise of the task group. Some terms for some forms of polymerization are based on named reactions. e.g. Kumada catalyst transfer polymerization, Ziegler-Natta polymerization. This form of terminology has been discouraged by SPT. However alternate names for these polymerizations are not immediately obvious.
The use of the term catalyst in a polymerization in is inconsistent and many times not in keeping with the IUPAC definition of catalyst.
Following email discussion of the draft in February that involved many task group members, it was decided to hold over further discussion on these topics until the Brazil SPT meeting.

Oct 2020 update – A document has been prepared and passed through SPT review. This is currently being finalized for submission to PAC.

Nov 2021 update – The provisional recommendation is available for comments till 31 March 2022

Last update 24 November 2021