what happens in a condensation polymerization reaction?
In a condensation polymerization reaction, two or more monomers combine to form a polymer while releasing a small molecule, typically water or alcohol, as a byproduct. This process involves the bonding of monomers through covalent bonds, resulting in a net loss of a molecule, which leads to polymer formation.
To understand the mechanism of a condensation polymerization reaction, we need to consider the following steps:
Step 1: Functional Group Activation - The reactive functional groups (such as carboxylic acid and alcohol groups) present in the monomers are activated. This activation can occur through various means, such as using catalysts, adjusting temperature, or modifying the pH of the reaction mixture.
Step 2: Formation of Covalent Bond - The activated functional groups of two monomers react with each other, forming a covalent bond. For example, in the case of a diacid and a dialcohol, the carboxylic acid group of one monomer reacts with the alcohol group of another monomer, resulting in the formation of an ester linkage. This reaction occurs through the elimination of a molecule, typically water or alcohol.
Step 3: Repeat the Process - The reaction continues until the desired polymer length is achieved. As the polymer chain grows, the byproduct molecules are eliminated at each step, resulting in an elongated polymer chain. The process can be carried out with two or more monomer types, leading to copolymers.
Step 4: Termination - The reaction is terminated when either all the monomers are consumed or controlled by external factors, such as adjusting the reaction conditions or adding an appropriate terminating agent.
Overall, the condensation polymerization reaction involves the repeated combination of monomers, their activation, and bonding, accompanied by the release of small molecules as byproducts.