Polymers
Types and Examples
What is a Polymer?
A polymer is a large molecule composed of repeating structural units called monomers, which are chemically bonded together.
Classification Based on Molecular Forces
- Elastomers – Stretchable rubber-like polymers e.g., Buna-S, Buna-N, Neoprene
- Fibres – Strong, thread-like polymers used in textiles e.g., Nylon 6,6, Polyesters (terylene)
- Thermoplastic Polymers – Soften on heating, reshaped multiple times e.g., PVC, Polyethylene
- Thermosetting Polymers – Hard, irreversible polymers e.g., Bakelite, Epoxy Resin
Classification Based on Mode of Polymerisation
- Addition Polymers – Formed by adding monomers without by-products e.g., Polyethylene, Polypropylene
- Condensation Polymers – Formed with elimination of small molecules (e.g., water) e.g., Terylene, Nylon 6, Nylon 6,6
Classification Based on Structure of Polymers
- Linear Polymers – Long chain of monomers e.g., Polyethylene, Nylon, PVC
- Branched Chain Polymers – Side chains attached to the main chain e.g., Low-Density Polyethylene (LDPE)
- Cross-linked or Network Polymers – Strongly interconnected networks e.g., Synthetic fibers (nylon 6,6), Synthetic rubbers (Buna-S)
Classification Based on Source
- Natural Polymers – Found in nature e.g., Cellulose, Starch
- Semi-synthetic Polymers – Chemically modified natural polymers e.g., Cellulose Acetate, Rayon, Vulcanized Rubber
- Synthetic Polymers – Man-made polymers e.g., PVC, Nylon, Teflon, Polyester, Bakelite