Structure-Property Relationships in a Polymer

Abstract

The way in which polymer molecular structure controls structure on higher levels of organization in a solid polymer is briefly reviewed, as is also the way in which structure, on all levels, controls physical properties. The “line of descent” from molecular structure to physical properties is then illustrated at length in the case of one particular polymer, cis-polyisoprene (natural rubber). It is shown how the crystalline-amorphous morphology in the solid is controlled both by the chemical microstructure of the polymer and by the physical conditions (temperature, time, strain) under which solidification occurs. By changing these “processing conditions” great changes can be effected in the morphology.

The mechanical properties of the solid are then examined as a function of morphology and shown to depend strongly on the various morphological parameters, such as the amount and orientation of the crystalline phase and the orientation and state (rubber or glass) of the amorphous phase.