One‐Step Process for Creating Triple‐Shape Capability of AB Polymer Networks

Triple‐shape polymers can move from a first shape (A) to a second shape (B) and from there to a third shape (C), where both shape changes are induced by temperature increases. This triple‐shape capability is obtained for multiphase polymer networks after application of a complex thermomechanical programming process, which consists of two steps; these steps create shapes (B) and (A), while shape (C) is defined by the covalent crosslinks of the polymer network. Here, the creation of the triple‐shape capability for an AB polymer network system by a simple one‐step process similar to a conventional dual‐shape programming process is reported. The polymer networks are based on poly(ε‐caprolactone) (PCL) and poly(cyclohexyl methacrylate); favorable compositions for obtaining a triple shape effect have a PCL content between 35 and 60 wt%. This finding substantially facilitates handling of the triple‐shape technology and is an important step toward the realization of potential applications in which more than one shape change is required.