Thermal and Photochemical Initiation of Radical Polymerisation

These flashcards cover key terminology and concepts related to radical polymerisation, including mechanisms, initiators, propagation, and stereochemistry.

Homolytic Cleavage

The process where a chemical bond breaks symmetrically, resulting in the formation of two radicals.

Thermal Initiators

Substances that decompose thermally to generate radicals for polymerisation, e.g., benzoyl peroxide.

Azoisobutyronitrile (AIBN)

A common thermally decomposed radical initiator used in polymerisation.

Redox Initiators

Initiators that operate through single electron transfer, generating radicals.

Photoinitiators

Substances that produce radicals upon exposure to light, starting polymerisation.

Propagation

The step in radical polymerisation where monomers add to growing chains, typically involving hundreds of steps.

Regiochemistry

The preference of certain structural configurations in polymerisation, influenced by temperature and structure.

Stereochemistry of Radical Polymerisation

Describes the structural arrangement of monomer units in the polymer, influencing properties such as tacticity.

Termination in Radical Polymerisation

The process where growing chain radicals combine or disproportionate, leading to finite chain lengths.

Chain Transfer

The process of transferring radical activity to another molecule, affecting molecular weight and branching in the polymer.

General Mechanism of Radical Polymerisation

The sequence of initiation, propagation, and termination leading to chain growth in radical polymerisation.

Intramolecular Reaction/Backbiting

A reaction occurring within the same chain that leads to short chain branches in the polymer.

Intermolecular Reaction

A reaction between different polymer chains leading to long chain branches.