On the cryogenic “degradation” of polystyrene in dilute solution

The effect of cryogenic treatment on dilute polystyrene solutions of different thermal history was studied by viscometry, size-exclusion chromatography, and static laser light-scattering measurements. The lowering of apparent molar mass during freezing of the solvent has its origin in a more compact conformation of the polymer chain resulting from the formation of intrachain segmental cohesion. Prior hypotheses about cryogenic degradation or chain scission in the polymer solution are incorrect.