Thermadapt Shape Memory PCL-co-PBA Network Exhibiting Tunable Properties and Dynamics of Ester–Ester Exchange Reactions

Abstract

Beyond self-repairability and reprocessability, permanent shape reconfigurability in thermadapt shape memory polymers (TSMPs) is a prominent functionality in dynamic covalent polymer networks. The design and synthesis of TSMPs with a wide range of tunable macroscopic properties that do not require sophisticated chemistry or modification are highly desirable for real-world device applications but are a significant challenge. Herein, we present a straightforward yet efficient strategy to prepare TSMPs with adjustable properties, good reconfigurability, and self-repairability via ester–ester exchange. The class of TSMPs is engineered as the architecture of AB copolymer networks (AB-CPNs), which are composed of the semicrystalline polycaprolactone (PCL) as the A-segment and the poly­(butyl acrylate) (PBA) as the B-segment. Regulating the weight content of the PCL segment in the thermadapt shape memory PCL-co-PBA networks can govern the network rearrangement kinetics, thermal properties, thermomechanical properties, switching temperature, and shape memory properties. The thermadapt shape memory AB-CPNs with ester–ester exchange do not require the introduction of extra hydroxyl groups, and their network structure is readily adjusted, allowing for considerable flexibility in the structure design and property adjustment. It is anticipated that a large family of thermadapt shape memory AB-CPNs with widely tunable macroscopic properties and the commercial availability of precursors will contribute significantly to real-world applications of SMP devices.

Photoreversible Shape Memory Polyurethane Films Prepared Using Demulsification-Induced Fast Solidification for Multilevel Information Encryption Application

“…The temperature data of the various thermal properties are summarized in Table S3. As shown in the cooling and heating curves in Figure b,c, the semicrystalline structure of the PCL within the WPU-A chain led to distinct soft segment crystallization temperatures ( T c 's) ranging from 21.9 to 7.7 °C (Figure b, cooling curve) and melting temperatures ( T m 's) ranging from 60.6 to 59.5 °C (Figure c, heating curve) in all samples. − As the content of the hard segment increased, both the T c and T m of WPU-A gradually moved to lower temperatures, underscoring a significant influence of the hard segment proportion on the crystallization behavior . This transformation occurred possibly due to the fact that the increase in the hard segment content disrupted the ordered arrangement of the soft segments, hindering the crystallization in the WPU-A film.…”