Answer:-

Polymers are categorized into distinct groups based on their intermolecular forces, including Elastomers, Fibres, Thermoplastic polymers, and Thermosetting polymers.

1. Elastomers:

   • Elastomers exhibit a unique elasticity property, allowing them to stretch under external force and return to their original shape upon force removal.
   • These elastic polymers are held together by relatively weak van der Waals intermolecular forces.
   • A limited number of crosslinks between polymer chains enable the stretched elastomer to retract to its original form when the applied force is removed.
   • Examples of elastomers include Vulcanized rubber, Buna-S, Buna-N, and neoprene.

2. Fibres:

   • Fibres are polymeric solids that can be drawn into threads and possess exceptional tensile strength, making them resistant to breaking under tension.
   • Their high tensile strength arises from strong intermolecular forces such as hydrogen bonding and dipole-dipole interactions.
   • These intermolecular forces result in a crystalline structure in fibres.
   • Common examples of fibres include Polyamides (nylon 6,6) and polyesters (terylene).

3. Thermoplastic Polymers:

   • Thermoplastic polymers exhibit plasticity, allowing them to be easily shaped or molded.
   • They can repeatedly soften when heated and harden when cooled.
   • These polymers possess moderately strong intermolecular forces, which fall between the forces found in elastomers and fibres.
   • Examples of thermoplastic polymers include Polyethylene, Polystyrene, and Polyvinyls.

4. Thermosetting Polymers:

   • Thermosetting polymers are rigid materials that can be shaped when heated but become permanently hardened once cooled.
   • Their hardening results from extensive cross-linking via covalent bonds formed during the hot molding or setting process.
   • Unlike thermoplastic polymers, thermosetting polymers cannot be softened or remolded by subsequent heating.
   • Notable examples of thermosetting polymers include Bakelite and urea-formaldehyde resin.