Laboratory On StructureProperty Relationship In Polymers

Objectives of this module:

To understand the influence of molecular weight on thermal and mechanical properties of polymers.

Specifically:

• To characterize the hydrodynamic size, virial coefficient and estimate the molecular weight using dynamic light scattering (DLS) technique.
• To understand the concepts behind light scattering technique and Zimm plot.
• To compound different molecular weight polystyrene (PS) and prepare tensile specimens.
• To perform differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile testing on specimens of different molecular weight.
• To explain the differences observed in the data between the two grades of PS.

What are the underlying theories/concepts?

• Brownian motion, random walk analysis, polymer solutions (good, poor, theta conditions, Flory-Huggins theory, and UCST/LCST conditions)
• Characterization of molecular weights and importance
• Importance of structural features of polymers and their influence on properties