These fundamental units are crucial in the chemical industry, as they are combined through polymerization processes to create a wide range of materials used in everyday products, including plastics, rubbers, and fibers.

Monomers can be classified based on their chemical structure and functionality, leading to various applications:

1. Types of Monomers:

   • Vinyl Monomers: These monomers contain a vinyl group (–CH=CH₂) and are commonly used to produce polyvinyl chloride (PVC) and polystyrene. Examples include ethylene, propylene, and styrene.
   • Diene Monomers: These contain two double bonds and are essential in producing synthetic rubbers, such as styrene-butadiene rubber (SBR) and polybutadiene.
   • Acrylic Monomers: These include compounds like methyl methacrylate (MMA) and are used to produce acrylic polymers, which are known for their clarity and UV resistance.
   • Condensation Monomers: These are used in the formation of polyesters and polyamides, such as terephthalic acid and hexamethylenediamine.

2. Polymerization Processes:

   • Addition Polymerization: Involves the addition of monomers with unsaturated bonds, leading to the formation of long-chain polymers. This process typically occurs in the presence of heat, light, or chemical initiators.
   • Condensation Polymerization: Involves the reaction between monomers with functional groups, resulting in the release of small molecules (e.g., water) as byproducts. This method is commonly used for polyesters and polyamides.

3. Applications:

   • Plastics: Monomers are essential in producing various plastic materials, such as polyethylene, polypropylene, and polycarbonate, which are widely used in packaging, automotive, and consumer goods.
   • Rubbers: Synthetic rubbers, such as SBR and nitrile rubber, are produced from diene monomers and are used in tires, seals, and gaskets.
   • Fibers: Monomers like nylon and polyester are used to create synthetic fibers for textiles, carpets, and industrial applications.