Cationic polymerization involves the presence of a strong cation, usually a strong Lewis acid for the initiation of the polymerization process, and stabilization of the polymer. The acid BF3 is a very strong Lewis acid, often used in the polymerization process. The strong cation attacks the electrons on the double bond of the alkene, displacing an electron, and binding to the alkene on the end. As a result, the alkene has formed a positive charge on its opposite end, as the cation has drawn an electron away from the alkene. The positive charge on the end is a binding site for the next monomer to attach, and the polymerization chain reaction begins.
Anionic polymerization operates on principles similar to cationic polymerization.
In anionic polymerization, a strong anion initiates the polymerization reaction by attacking the back-side of the alkene, breaking its double bond, displacing an electron and as a result, induces a negative charge on the opposite end of the alkene. In the following propagation steps, the polymerization chain reaction continues as monomers attach to each subsequent negatively charged monomer. Super glue s strength comes from its constitutive part, cyano-acrylate, which can catalyze rapid polymerization in contact with any trace acid. As a result, Super Glue will polymerize rapidly, and on any surface with even a trace of acid - like between your skin and a toilet seat. Condensation Polymer Reactions Condensation polymers are formed by ester or amide linkages between two difunctional molecules.