THE EFFECT OF METAL-HALIDES ON THE DEFORMATION MECHANISM OF THIN-FILMS OF NYLON

Soaking of nylon 6 and 66 films in saline solutions modifies their deformation response to an applied tensile stress. Unsalted films do not show conventional crazes. Instead they are seen to deform by a mixture of shear and fibrillated shear, the latter involving chain disentanglement. Dried salt-soaked films are, however, dominated by scission crazing for all temperatures below the glass transition temperature. Salt treatment modifies intermolecular bonding, strengthening it in the process, and stiffens the polymer chains. Such modifications act to suppress shear and chain disentanglement. Calcium and zinc chlorides both reduce the temperature dependence of the strain for deformation onset and embrittle films, with nylon 6 much more affected than nylon 66. Sodium chloride acts only as a weak crazing agent for both nylon types.