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: 1. To characterize the hydrodynamic size, virial coefficient and estimate the molecular weight using dynamic light scattering (DLS) technique. 2. To understand the concepts behind light scattering technique and Zimm plot. 3. To compound different molecular weight polystyrene (PS) and prepare tensile specimens. 4. To perform differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile testing on specimens of different molecular weight. 5. To explain the differences observed in the data between the two grades of PS. What are the underlying theories/concepts? 1. Brownian motion, random walk analysis, polymer solutions (good, poor, theta conditions, Flory-Huggins theory, and UCST/LCST conditions) 2. Characterization of molecular weights and importance 3. Importance of structural features of polymers and their influence on properties