Polymers
1.0 Introduction
2.0 Polymers and polymerization
3.0 Free-radical vinyl polymerization
4.0 Ionic Polymerization
5.0 Natural Rubber
6.0 Synthetic Rubber
7.0 Polyvinyl Chloride (PVC)
8.0 Teflon or PTFE (Polytetrafluoro ethylene)
9.0 Nylon-66
3.1 Copolymerization
Polymerization of a single monomeric compound to form a homopolymer is known as homopolymerization. Evidently such a polymer is made up of identical units. In contrast, a copolymer results when two different kinds of monomers are polymerized together to give a product containing both the monomers.
Such as process, known as copolymerization, is of great industrial importance as it enables us to get a polymer possessing desired properties.
To a certain extent we can control the composition of a copolymer by varying the proportions of the monomer in the polymerizing mixture. However, the composition of the polymer depends not only on the relative concentrations of the two monomers, but also on the relative reactivities of the monomers toward free radical addition.
In other words, a more reactive monomer has greater chance of being incorporated into a copolymer. As the reactivity of a carbon-carbon double bond toward free radical addition is affected by the stability of the new free radical being formed, the more stable free radicals will preferentially be produced.
Copolymerization of styrene with methyl methacrylate to produce polystyrene (co-methyl methacrylate) $(A)$ is an industrially important process.
Saran Wrap $(B)$ is another copolymer formed by the copolymerization of vinylidene and vinyl chlorides.
