additionspolymerisationer

Addition polymerization is a type of polymerization reaction in which monomers are added to a polymer chain in such a way that the monomer does not lose any atoms to form the polymer. This process is characterized by the absence of by-products, unlike condensation polymerization. The reaction typically proceeds via a radical, cationic, or anionic mechanism, depending on the initiating species and reaction conditions.

In radical addition polymerization, the reaction is initiated by a radical species, which can be generated through various methods such as thermal decomposition, photolysis, or redox reactions. The radical then attacks the monomer, forming a new radical that can propagate the chain by adding more monomers. The process continues until the reaction is terminated by recombination, disproportionation, or transfer to another molecule.

Cationic addition polymerization involves the use of a cationic initiator, which generates a carbocation that attacks the monomer. The carbocation then propagates the chain by adding more monomers, and the reaction is terminated by proton transfer or electron pair donation.

Anionic addition polymerization, on the other hand, uses an anionic initiator to generate a carbanion, which attacks the monomer. The carbanion then propagates the chain by adding more monomers, and the reaction is terminated by proton transfer or electron pair donation.

Addition polymerization is widely used in the production of various polymers, including polyethylene, polypropylene, and polystyrene. These polymers have diverse applications in industries such as packaging, textiles, and electronics. The choice of polymerization mechanism depends on the specific requirements of the polymer, such as molecular weight, molecular weight distribution, and tacticity.