A PROCESS FOR OBTAINING RECOVERABLE DEFORMATIONS IN SHAPE MEMORY POLYMERS (SMP)

摘要

The present invention relates to the large, elastic recoverable (thermo-mechanically induced) deformations of a hollow or solid, epoxy or other shape memory polymer (SMP) based material specimens realized through selective zonal heating using non-contact type of heating techniques. These deformations may be in axial, bending or shear mode. This invention is based on the differential modulus created by selective zonal heating followed by cooling. These heat cool cycles may further be broken down into heating selective zones (to varying temperatures) of the SMP specimen to a temperature above the transition temperature, (Tg or Tm) (2) elastically deforming by mechanical loading, (3) cooling under load, (4) completely unloading in cold state and (5) again re-heating to a temperature above transition temperature. The selective heating is done in such a way so as to effect large elastic deformations in the specimen. The differential modulus between the zones at a higher temperature and those zones at a lower temperature results in large elastic deformations. These are almost completely recoverable in both quasi-static and cyclic types of thermo mechanical loading for all modes of deformation.