Effect of molecular weight on strength and deformation characteristics of oriented amorphous polymers

Tensile tests were carried out on uniaxially oriented films of several amorphous linear polymers (polymethyl methacrylate, polystyrene, and poly-2,2-octamethylene-5,5-dibenzimidazol) of various molecular weights. It was shown that molecular weight has no direct effect on polymer strength, which is determined by structure. However, when polymer fibers and films are formed and stretched, the molecular weight of a given material affects the orientation of macromolecules and so predetermines the structure of the products obtained and, consequently, their strength.Mekhanika Polimerov, Vol. 3, No. 4, pp. 579–585, 1967