Throughout the last 25 years, computational chemistry based on quantum
mechanics has been applied to the investigation of reaction kinetics in free radical
polymerization (FRP) with growing interest. Nowadays, quantum chemistry (QC) can
be considered a powerful and cost-effective tool for the kinetic characterization of many
individual reactions in FRP, especially those that cannot yet be fully analyzed through
experiments. The recent focus on copolymers and systems where secondary reactions play
a major role has emphasized this feature due to the increased complexity of these kinetic
schemes. QC calculations are well-suited to support and guide the experimental investigation
of FRP kinetics as well as to deepen the understanding of polymerization mechanisms. This
paper is intended to provide an overview of the most relevant QC results obtained so far from
the investigation of FRP. A comparison between computational results and experimental data
is given, whenever possible, to emphasize the performances of the two approaches in the
prediction of kinetic data. This work provides a comprehensive database of reaction rate
parameters of FRP to assist in the development of advanced models of polymerization and
experimental studies on the topic.