Ternary Polymeric Composites Exhibiting Bulk and Surface Quadruple‐Shape Memory Properties

Abstract

We report the design and characterization of a multiphase quadruple shape memory composite capable of switching between 4 programmed shapes, three temporary and one permanent. Our approach combined two previously reported fabrication methods by embedding an electrospun mat of PCL in a miscible blend of epoxy monomers and PMMA as a composite matrix. As epoxy polymerization occurred the matrix underwent phase separation between the epoxy and PMMA materials. This created a multiphase composite with PCL fibers and a two-phase matrix composed of phase-separated epoxy and PMMA. The resulting composite demonstrated three separate thermal transitions and amenability to mechanical programming of three separate temporary shapes in addition to one final, equilibrium shape. In addition, quadruple surface shape memory abilities are successfully demonstrated. The versatility of this approach offers a large degree of design flexibility for multi-shape memory materials.

4D printing of polylactic acid (PLA)/thermoplastic polyurethane (TPU) shape memory polymer – a review

“…SMP can be further divided based on how many transient shapes they can remember. For example, SMPs can be classified into dual or one-way SMPs [58], triple SMPs [59], and multiple-way SMPs [60]. Polymers called Dual SMPs have one permanent shape and one temporary shape [61].…”

Thermoactive Smart Electrospun Nanofibers

“…With a more articulated process, a quadruple shape memory effect was also obtained by introducing an electrospun mat of PCL in a blend of epoxy monomers and PMMA, which achieved phase separation during epoxy crosslinking. [ 178 ] The obtained system, a ternary composite with heterogeneous structure, shows three well‐distinguished transitions temperatures for each phase.…”

Shape-Memory Materials via Electrospinning: A Review

“…Furthermore, many studies were focused on the processing of multiphase shapememory materials. For instance, Buffington et al [85] designed quadruple shape-memory composites, which are materials that can recover their original shape from three formerly programmed shapes [86], constituted by an electrospun mat of PCL, epoxy monomer, and poly(methyl methacrylate) (PMMA), and with three distinct transition temperatures. Sessini et al [87] obtained a sandwich-type structure based on two external films of shapememory Surlyn ® and an inner layer of electrospun PLA mat.…”