Freeradicalpolymerisaatio

Freeradical polymerization is a type of chain-growth polymerization mechanism that involves the formation of free radicals, which are highly reactive molecules with an unpaired electron. This process is widely used in the production of various polymers, including synthetic rubbers, plastics, and adhesives. The mechanism begins with the initiation step, where a free radical is generated from an initiator molecule, typically through the absorption of heat or light. This initiator radical then reacts with a monomer, forming a new radical and starting the chain reaction.

In the propagation step, the newly formed radical reacts with another monomer molecule, adding it to the growing polymer chain and creating another radical. This step repeats, with each new radical reacting with another monomer, causing the polymer chain to grow longer. The propagation step continues until the reaction is terminated.

Termination occurs when two radicals combine, forming a stable molecule and ending the chain growth. There are two main types of termination: combination, where two radicals join to form a single molecule, and disproportionation, where one radical donates an electron to another, resulting in two different molecules. The efficiency of the termination step can significantly impact the molecular weight and properties of the resulting polymer.

Freeradical polymerization offers several advantages, including high reaction rates, the ability to produce a wide range of polymers, and the potential for controlled polymerization through techniques like living radical polymerization. However, it also has limitations, such as the potential for side reactions and the difficulty in controlling the molecular weight and polydispersity of the resulting polymers. Despite these challenges, freeradical polymerization remains a fundamental process in the field of polymer chemistry.