Chain transfer
In polymer chemistry, a chain transfer reaction is an event during a polymerization reaction by which the activity of a growing polymer chain is transferred to another molecule: P ∙ + XR ⟶ PX + R ∙ {\displaystyle {\ce {P}}^{\bullet }+{\ce {XR -> PX + R}}^{\bullet }} where • is the active center, P is the initial polymer chain, X is the end group, and R is the substituent to which the active center is transferred. Chain transfer reactions reduce the average molecular weight of the final polymer.