Multiple‐Shape Memory Polymer Blends Formed by Massive Formation of Interphases via Ultrahigh Plastic Deformation

Abstract The development of advanced shape memory polymers (SMPs) requires the creation of approaches that offer the possibility of forming different temporal shapes as well as changing the corresponding shape memory transition temperatures. A distinctive feature of ultrahigh plastic deformation methods is the possibility of producing polymer blends with a maximum content of interface to form a single broad thermal transition. This can be an attractive way to produce multi‐SMPs based on a simple processing technique. Two polymer pairs—glycol‐modified polyethylene terephthalate/polylactide (PETG/PLA), glycol‐modified polyethylene terephthalate/polybutylene terephthalate (PETG/PBT)—are used to form an immiscible symmetrical blend (50 wt%/50 wt%). Ultrahigh plastic deformation is achieved by high pressure torsion (HPT). HPT leads to intimate mixing of the chains of the respective polymer pairs. Thermomechanical programming successfully enables a triple shape memory effect with fine shape memory parameters.