| Addition Polymerization | Condensation Polymerization |
|---|---|
| Monomer units contain double or triple bond (reactive site) which combine in succession to give a polymer. | Monomer units contain two or more functional groups which react with each other to undergo condensation. |
| Monomers add on to yield a polymer without elimination of any by product. | Monomers combine to form a polymer with elimination of small molecules like H2O, HCl, NH3, CH3OH. |
| It is a chain reaction. | It is an intermolecular reaction. |
| It involves free radical or ionic mechanism. | It follows the mechanism of condensation or esterification. |
| It leads to formation of homochain polymers. | It leads to formation of heterochain polymers. |
| Molecular weight of polymer is an exact multiple of monomeric units. | Molecular weight of polymer is not an exact multiple of monomeric units. |
| Generally, thermoplastics are obtained. | Both thermoplastics and thermosets are obtained. |
| High molecular mass polymer is obtained immediately. | Molecular mass of polymer increases steadily through the reaction. |
| Radical initiator, Lewis acid or base is required. | Mineral acids and bases are used as catalyst. |
| Addition polymers are formed quickly. | Reaction is completed in different independent steps taking a definite period of time. |
| Common examples are polythene, polypropylene, PVC etc. | Common examples are terylene, bakelite etc. |
