Polymers

• Polymers are a class of large molecules made up of repeating subunits, known as monomers.
• These monomers join together in a process called polymerisation to form a long chain-like structure.
• There are two types of polymerisation processes: addition polymerisation and condensation polymerisation.
• During addition polymerisation, monomers with unsaturated bonds (carbon-carbon double bonds) link together in a chain, often initiated by heat or a catalyst. Polyethylene and PVC (polyvinyl chloride) are examples of polymers made through addition polymerisation.
• However, in condensation polymerisation, monomers with two functional groups combine. This process also results in the creation of a smaller molecule, like water. Examples of such polymers are proteins and nylon.
• A common classification of polymers is based on their source or origin: synthetic and biopolymers. Synthetic polymers are derived from petroleum oil and include polyethylene, polypropylene, and polyvinyl chloride. Meanwhile, biopolymers are created from living organisms and include DNA, proteins, starch, and cellulose.
• Another distinction in polymers is based on their response to heat: thermoplastics and thermosetting plastics. Thermoplastics become pliable or moldable above a specific temperature and solidify upon cooling. Examples include polyethylene, PVC, polypropylene. Thermosetting plastics are polymers that set permanently and cannot return to their original form after heating. These include urea-formaldehyde, epoxy resin, and melamine-formaldehyde.
• Polymers can exhibit different properties based on their molecular structure and weight. They can be stiff and brittle, or soft and elastic.
• The structure of a polymer can be depicted as being either linear, branched or cross-linked.
• Each polymer’s properties - from resilience, temperature resistance to chemical stability - are determined by the types of monomers used, the structure of the polymer chain, and the molecular weight.
• Polymers play a crucial role in everyday life, with uses in countless sectors, such as the plastics industry, textile field, in the production of coatings, adhesives, elastomers, and more.