Syllabus
1. Experimental methods for studying relaxation processes (viscoelastic, dielectric, NMR). Relations between macrocscopic characteristics and micropysical description of the system. Relaxation times, autocorrelation function, spectral density, correlation time.
2. Models for molecular motions: rotational diffusion model, Debye formula. Coil model of a polymer chain, Rouse model, hydrodynamic interactions, Zimm model. Entanglements, reptation model. Models starting with crystalline ordering, bundle model, kinks, meander model.
3. Temperature dependence of relaxation behaviour. Arrhenius formula, model with jumps over the potential barrier. Free volume model, WLF equation. Adams-Gibbs theory. Temperature dependence of relaxation times for the meander model.
4. Glass temperature, relaxation processes in the glassy state, physical ageing. Order parameters, Kovacs' theory (both one- and multiparameter one).
Annotation
The explanation of the models of relaxation behaviour of polymers. The interpretation of the experimental results obtained from different relaxation methods.