1. Polymers (Classification And Polymerisation Types)

Polymers are large molecules (macromolecules) composed of many repeating structural units, called monomers, joined together by covalent bonds. They can be classified based on their source (natural, semi-synthetic, synthetic), structure (linear, branched, cross-linked), or mode of polymerization. Polymerization is the process of linking monomers. Key types include addition polymerization (monomers add to each other without loss of atoms, e.g., polyethene) and condensation polymerization (monomers join with the elimination of small molecules like water, e.g., nylon).

2. Polymers (Properties And Biodegradable Polymers)

Polymer properties, such as strength, elasticity, and thermal behavior, depend on the monomer structure, chain length, and inter-chain forces. Polymers can be thermoplastics (soften on heating, e.g., PVC) or thermosetting plastics (do not soften on heating, e.g., Bakelite). Growing environmental concerns have led to interest in biodegradable polymers, such as polylactic acid (PLA) and polyhydroxyalkanoates (PHAs), which can be decomposed by microorganisms, offering sustainable alternatives to conventional plastics.