Radical polymerization is a widely used method for producing high molecular weight polymers. It involves the formation of free radicals, which are highly reactive species with unpaired electrons. The process can be divided into four main steps: initiation, propagation, chain transfer, and termination. Each step contributes to the formation of high molecular weight polymers in different ways.1. Initiation: This is the first step in radical polymerization, where the formation of free radicals occurs. It can be achieved through various methods, such as thermal decomposition of an initiator, redox reactions, or exposure to UV light. The initiator molecules break down into free radicals, which are highly reactive due to their unpaired electrons. These radicals can now react with the monomer molecules, forming a covalent bond and generating a new radical species. This step is crucial for starting the polymerization process.2. Propagation: In this step, the newly formed radical species reacts with another monomer molecule, forming a covalent bond and generating a new radical. This process continues, with the radical reacting with more monomer molecules, leading to the growth of the polymer chain. The propagation step is responsible for the formation of high molecular weight polymers, as the chain continues to grow until it is terminated.3. Chain transfer: During the propagation step, the growing polymer chain can sometimes transfer its radical to another molecule, such as a solvent, monomer, or another polymer chain. This results in the termination of the original chain's growth and the initiation of a new chain. Chain transfer can affect the molecular weight distribution of the resulting polymers, as it can lead to the formation of shorter chains. However, it can also contribute to the overall polymerization rate, as the newly formed radicals can initiate new chains.4. Termination: The polymerization process eventually comes to an end when two radicals react with each other, resulting in the formation of a stable covalent bond. This step is called termination, and it can occur through various mechanisms, such as combination two radicals joining together or disproportionation one radical transferring its unpaired electron to another, forming a double bond in one chain and a saturated chain in the other . Termination stops the growth of the polymer chains, and the final molecular weight of the polymers is determined by the balance between propagation and termination.In summary, the steps involved in a radical polymerization reaction contribute to the formation of high molecular weight polymers by initiating the reaction with free radicals, allowing the polymer chains to grow through propagation, occasionally transferring the radicals to other molecules, and finally terminating the reaction. The balance between these steps determines the final molecular weight and distribution of the resulting polymers.