THE ROLE OF INDIVIDUAL CHAINS IN POLYMER DEFORMATION

The characteristic properties of molecular chains are their length, an isotropy and mobility. Although the macroscopic (mechanical) propertie s of polymers basically reflect these molecular characteristics, it is not always easy to identify the response of an individual molecule to stress. Much of the scientific work of Ward has been devoted to this problem and it is for this reason that some specific aspects of the st ress transfer through chain molecules will be elaborated here. Thus, t he representation of molecular anisotropy through aggregate models, th e extreme situations of stress transfer through tie-molecules in semic rystalline fibres (shear stresses up to 3.5 GPa) and in elongational f low will be discussed. Recent results of stress transfer across interf aces in cracked homopolymers and in blends will be reviewed.