Structural phenomena in polymers arising at low temperatures and by the action of high forces

Abstract

AbstractNew structural phenomena which can be produced in polymers at low temperatures or by the action of high forces are described and discussed. Experimental evidence supports the argument that the deformation of polymers can develop not only as a result of conformational changes of the macromolecules proper but also by transformation of more complex structural formations. The consequence of this phenomenon is the possibility of large deformations far below the glass‐transition temperature in a crystalline polymer with well‐developed supermolecular structure. This type of deformation takes place without molecular orientation. Another phenomenon discussed is the sharp change of supermolecular structure in crystalline polymers caused by the action of a shock wave. These effects ought to be connected with an energetic rather than entropic deformation mechanism because the transformations occur at a supermolecular level. Thus, there can be two extreme types of deformation processes: the well‐known conformation changes that occur at a molecular level, and the deformation of supermolecular structures. Examples of the pure form of the latter type of mechanism obtained under extreme conditions are given.