TY - JOUR
T1 - Thermally-triggered multi-shape-memory behavior of binary blends of cross-linked EPDM with various thermoplastic polyethylenes and their potential applications as temperature indicators
AU - Pommer, Reinhold
AU - Saf, Robert
AU - Supplit, Ralf
AU - Holzner, Armin
AU - Plank, Harald
AU - Trimmel, Gregor
N1 - Publisher Copyright:
© 2023 The Authors
PY - 2023/10/6
Y1 - 2023/10/6
N2 - Shape-memory polymers (SMPs) are smart materials that can alter their configuration in response to external stimuli. They have shown promise in a number of application areas, including soft robotics or biomedical devices. Frequently, however, the materials needed are expensive, or labor-intensive synthetic processes are involved. In this contribution, we report a versatile and cost-effective manufacturing method for SMPs based on binary elastomer-thermoplastic-blends. These were produced from ethylene-propylene-diene monomer rubber (EPDM) combined with ultra-low-density polyethylene (ULDPE), propylene-ethylene copolymer (PP-c-PE), or high-density polyethylene (HDPE) as thermoplastic components. Atomic force microscopy revealed an immiscible two-phase morphology. Results of dynamic-mechanical thermal analysis showed that all polymer blends with a high thermoplastic load had efficient thermo-responsive dual-shape-memory, also demonstrated on macroscopic specimens. Furthermore, multi-shape-memory of elastomer/thermoplastic (40/60)-blends was investigated. Especially ULDPE-containing blends exhibited particularly promising multi-shape-memory features and stepless, controllable temperature response. Mechanistically, this is based upon the synergistic interaction of the cross-linked elastomer and the thermoplastic switching phase, consisting of different crystalline segments melting over a wide range from 60 to 125 °C. The continuous shape recovery over a broad temperature range could be used to create reusable test strips, e.g., for indicating exposure temperature in transportation chains or overheating protection.
AB - Shape-memory polymers (SMPs) are smart materials that can alter their configuration in response to external stimuli. They have shown promise in a number of application areas, including soft robotics or biomedical devices. Frequently, however, the materials needed are expensive, or labor-intensive synthetic processes are involved. In this contribution, we report a versatile and cost-effective manufacturing method for SMPs based on binary elastomer-thermoplastic-blends. These were produced from ethylene-propylene-diene monomer rubber (EPDM) combined with ultra-low-density polyethylene (ULDPE), propylene-ethylene copolymer (PP-c-PE), or high-density polyethylene (HDPE) as thermoplastic components. Atomic force microscopy revealed an immiscible two-phase morphology. Results of dynamic-mechanical thermal analysis showed that all polymer blends with a high thermoplastic load had efficient thermo-responsive dual-shape-memory, also demonstrated on macroscopic specimens. Furthermore, multi-shape-memory of elastomer/thermoplastic (40/60)-blends was investigated. Especially ULDPE-containing blends exhibited particularly promising multi-shape-memory features and stepless, controllable temperature response. Mechanistically, this is based upon the synergistic interaction of the cross-linked elastomer and the thermoplastic switching phase, consisting of different crystalline segments melting over a wide range from 60 to 125 °C. The continuous shape recovery over a broad temperature range could be used to create reusable test strips, e.g., for indicating exposure temperature in transportation chains or overheating protection.
KW - Elastomer-thermoplastic-blends
KW - Multi-shape-memory
KW - Shape-memory polymers (SMPs)
KW - Stimuli-responsive materials
KW - Temperature indication
KW - Thermomechanical properties
UR - http://www.scopus.com/inward/record.url?scp=85169617327&partnerID=8YFLogxK
U2 - 10.1016/j.polymer.2023.126302
DO - 10.1016/j.polymer.2023.126302
M3 - Article
AN - SCOPUS:85169617327
SN - 0032-3861
VL - 284
JO - Polymer
JF - Polymer
M1 - 126302
ER -