Question

Q5) On the axes below, sketch and label relaxation modulus vs. temperature curves for the following polymers. Label the axes and provide a specific example of each of the three polymers. Also include a basic sketch illustrating the relevant microstructure of each polymer. i. A highly crystalline thermoplastic polymer ii. A semi-crystalline thermoplastic polymer iii. A highly cross-linked network polymer

Answer 1

Relanahon modulus Temperatore (°c) A - Highly crystalline thermoplashs polymer eg: Polystyrene. Glass transition regions is limited -small amount of amoophous maksial. B - Semi-crystallie thermoplashc polymos. eg: lightly cross-linked atacha polystyrene - leathesy regions extends to decompositors temperature - no melting.

Example for highly cross linked polymers are: polyester fibreglass , epoxy resins, polyurethanes de Glassy plateau Relanahon modulus Loge E Crosslinked ..- t Rubbory plateau uncsosslinked Tempersat toe
Examples: Highly crystalline thermoplastic polymer: Isostatic polystyrene

Semi-crystalline thermoplastic polymers: polyamide (Nylon), Polyoxymethylene (Acetal), Polyethylene teraphthalate(PET).

Cross-linked polymers/Network polymers: Polyesters, Polyurethanes, Epoxy resins