Addition polymerization and condensation polymerization are two major types of polymerization reactions that produce polymers with distinct properties. Here are the main differences between the two:1. Monomers involved:Addition polymerization: Involves monomers with a carbon-carbon double bond or another reactive group e.g., nitrile, isocyanate that can open up and form a single bond with another monomer.Condensation polymerization: Involves monomers with two or more reactive functional groups e.g., carboxylic acid, alcohol, amine that can react with each other to form a covalent bond and release a small molecule, usually water or methanol.2. Reaction mechanism:Addition polymerization: The reaction proceeds through a chain-growth mechanism, where the polymer chain grows by successive addition of monomers to an active site radical, cation, or anion .Condensation polymerization: The reaction proceeds through a step-growth mechanism, where monomers or oligomers react with each other to form larger molecules, and the polymer chain grows by successive condensation reactions.3. By-product formation:Addition polymerization: No small molecules are released during the reaction.Condensation polymerization: A small molecule, such as water or methanol, is released as a by-product during the reaction.4. Molecular weight distribution:Addition polymerization: Generally results in polymers with a narrow molecular weight distribution.Condensation polymerization: Typically produces polymers with a broader molecular weight distribution.5. Polymer properties:Addition polymers: Usually have a more regular structure, higher molecular weight, and better mechanical properties.Condensation polymers: Often have a more irregular structure, lower molecular weight, and may exhibit lower mechanical properties.Examples of each type of polymerization and their properties:Addition polymerization:Polyethylene PE is produced by the addition polymerization of ethylene. It is a linear, high molecular weight polymer with excellent mechanical properties, such as tensile strength and impact resistance. It is widely used in packaging materials, pipes, and films.Condensation polymerization:Polyethylene terephthalate PET is produced by the condensation polymerization of ethylene glycol and terephthalic acid. It is a polyester with a more irregular structure and lower molecular weight compared to PE. PET has good mechanical properties, but it is more susceptible to hydrolysis and degradation under certain conditions. It is widely used in the production of bottles, fibers, and films.In summary, the main differences between addition and condensation polymerization are the monomers involved, reaction mechanism, by-product formation, molecular weight distribution, and the properties of the resulting polymers. These differences lead to distinct applications and performance characteristics for the polymers produced by each method.