polyaddition

A polymerization in which the growth of polymer chains proceeds by addition reactions between molecules of all degrees of polymerization.
Notes:
  1. The growth steps are expressed by:
    P x + P y → P x + y { x } ∈ { 1 , 2 , ... ∞ } ; { y } ∈ { 1 , 2 , ... ∞ }
    where P x and P y denote chains of degrees of polymerizationx and y, respectively.
  2. The earlier term 'addition polymerization' embraced both the current concepts of 'polyaddition' and 'chain polymerization', but did not include 'condensative chain polymerization'.
Source:
PAC, 1996, 68, 2287 (Glossary of basic terms in polymer science (IUPAC Recommendations 1996)) on page 2307