A MODE-COUPLING THEORY CATASTROPHE SCENARIO DESCRIPTION OF RELAXATIONS IN SEMICRYSTALLINE NYLONS

In the conception of mode-coupling theory the liquid-glass transition is due to topological singularities (mathematical catastrophes) in a s ystem's parameter space. It is shown that previously published dielect ric relaxation data for a number of semicrystalline polymers (polyalan ine, polyglycine, nylon 3 and nylon 4) exhibit the characteristic sign atures for an A(4)-singularity: inflection points, linear regions in l n(omega), l/f noise regions, as well as a double minimum. Besides agre eing qualitatively with mode-coupling theory predictions, the data can also be described quantitatively with the A(4)-scenario.