New evidence for molecular entanglements

Abstract

Abstract Torsional creep and creep recovery measurements have been made on a 56% polymer weight solution of an extremely high molecular weight polystyrene ( M = 4.4 × 10 7 ) in tri‐ m ‐tolyl phosphate and on the polymer itself after recovery both from relatively dilute and more concentrated solution in benzene by freeze drying. Although viscoelastic steady state was not achievable, an anomalously shorter rubbery plateau in the response of the bulk polymer relative to its solution was indicated. On the basis of the assumed presence of physical entanglements of the threadlike molecules, which determine the length and height of the rubbery plateau, it was predicted and confirmed that the undiluted polystyrene recovered from dilute solution would have the highest and shortest creep compliance plateau.