Question

What is condensation polymerization, and how does it differ from addition polymerization? Give an example of a common condensation polymer.

Short answer

Condensation polymerization is a chemical reaction where monomers combine to form a polymer, releasing a small molecule as a byproduct, such as water or methanol. This occurs through the formation of new covalent bonds between monomers that contain two reactive functional groups. In contrast, addition polymerization involves unsaturated monomers containing carbon-carbon double bonds that react to form a polymer chain without releasing any byproducts. The primary differences between the two processes lie in the presence of byproducts, monomer properties, and reaction mechanisms. A common example of a condensation polymer is Nylon-6,6, formed by the reaction between a diamine and a diacid, used in fibers, textiles, and other materials.

Step-by-step solution

Definition of Condensation Polymerization

Condensation polymerization is a chemical reaction in which monomers combine to form a polymer, along with the release of a small molecule as a byproduct, such as water, methanol, or hydrogen chloride. This reaction usually involves monomers that contain two reactive functional groups (like -OH, -NH₂, -COOH, etc.), which bond together through the formation of new covalent bonds, leading to the release of a byproduct.

Definition of Addition Polymerization

Addition polymerization, on the other hand, is a chemical reaction in which unsaturated monomers (usually containing a carbon-carbon double bond) react with each other to form a polymer chain, without the release of any byproducts. In this process, the carbon-carbon double bond in the monomer breaks, and each carbon atom forms a new covalent bond with the neighboring monomer, leading to the formation of a long polymer chain.

Differences between Condensation and Addition Polymerization

The major differences between condensation and addition polymerization are: 1. Byproducts: Condensation polymerization releases a small byproduct during the reaction, while addition polymerization does not release any byproducts. 2. Monomers: Monomers in condensation polymerization contain reactive functional groups like -OH, -NH₂, or -COOH, etc., while monomers in addition polymerization contain a carbon-carbon double bond. 3. Reaction Mechanism: The reaction mechanisms of these two types of polymerizations are different. In condensation polymerization, new covalent bonds form between the functional groups of monomers while releasing a byproduct; whereas, in addition polymerization, the double bond of the monomer breaks and forms new covalent bonds with neighboring monomers.

Example of a Common Condensation Polymer

One common example of a condensation polymer is Nylon-6,6, which is a widely used synthetic polymer. It is formed by the reaction between a diamine (hexamethylenediamine, containing -NH₂ groups) and a diacid (adipic acid, containing -COOH groups). During the reaction, an amide bond forms between the -NH₂ group of the diamine and the -COOH group of the diacid, releasing water as a byproduct. The resulting polymer chain, Nylon-6,6, is widely used for the manufacture of fibers, textiles, and other materials. In conclusion, the key difference between condensation and addition polymerization lies in the reaction mechanism and the presence of byproducts. By understanding these differences, we can better comprehend the process of polymerization and the resulting polymer materials.