Sketch the repeat structure for each of the following alternating copolymers: (a) poly (butadiene-chloroprene), (b) poly(styrene-methyl methacrylate), and (c) poly(acrylonitrilevinyl chloride).

Polymer chemistry is a branch of chemistry that focuses on the synthesis, structure, and properties of polymers. Polymers are large molecules composed of repeating structural units called monomers, which are bonded together to form long chains. In the context of alternating copolymers, two different monomers are arranged in an alternating sequence along the polymer chain. This can significantly affect the physical and chemical properties of the polymer, including its strength, flexibility, thermal stability, and chemical resistance.

Understanding the structure of alternating copolymers is crucial as they are used in diverse applications, from industrial materials to everyday products. For example, the copolymer of butadiene and chloroprene is used for applications requiring oil and chemical resistance, while poly(styrene-methyl methacrylate) finds usage in plastic manufacturing with improved dimensional stability. Similarly, poly(acrylonitrile-vinyl chloride) is known for its flame retardancy and is used in applications such as fibers and plastics where flame resistance is important.

The monomers that make up a polymer are the building blocks from which the polymer is constructed. The structure of a monomer includes its size, shape, and the types of bonding sites that it offers for chemical reactions. In the exercise, monomers such as butadiene, chloroprene, styrene, methyl methacrylate, acrylonitrile, and vinyl chloride were identified. Each of these monomers has different functional groups, such as double bonds or chloride groups.

The monomer's structure dictates how it will interact with other monomers during polymerization to form the polymer chains. In alternating copolymers, the order and chemical nature of the monomers affect the final product's properties. For instance, the presence of a chlorine atom in chloroprene and vinyl chloride provides different chemical resistances and contributes to the thermal stability of the resulting copolymer when compared to monomers without chlorine.

Chemical bonding is the force that holds atoms together in molecules, including monomers and polymers. The primary type of bonding involved in polymer chemistry is covalent bonding, where electrons are shared between atoms to form molecules. During the formation of alternating copolymers, covalent bonds are created between the monomers in a specific order to ensure the 'alternating' architecture. This sequential bonding impacts both the physical and chemical properties of the resulting polymer.

For example, the alternating sequence in poly(butadiene-chloroprene) involves the regular alternation of butadiene and chloroprene monomers, which directly influences the copolymer's elasticity and resistance properties. Similarly, the distinct chemical bonding in poly(styrene-methyl methacrylate) and poly(acrylonitrile-vinyl chloride) frames their unique characteristics. These alternating copolymers demonstrate how the control over chemical bonding at the molecular level can tailor polymers for desired applications.