Tunable Multiple-Shape Memory Polyethylene Blends

• Published in: Macromolecular chemistry and physics 2013-12, Vol.214 (23), p.2725-2732
• Main Authors: Hoeher, Robin, Raidt, Thomas, Krumm, Christian, Meuris, Monika, Katzenberg, Frank, Tiller, Joerg C.
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-linked polyethylene; Exact sciences and technology; Gain; Mechanical properties; multiple-shape memory; Organic polymers; Physicochemistry of polymers; polyethylene; Polyethylenes; Polymer blends; polymer networks; Programming; Properties and characterization; Shape memory; shape-memory polymers; Storage capacity; Strain; strain storage
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/macp.201300413

Shape memory polymers (SMPs) are an important class of smart materials. Usually, these polymers can be switched between two shapes. Recently, the possibility of switching more than two shapes was introduced for SMPs with relatively low strain storage capability. In this work, a lightly cross‐linked polyethylene blend comprising 80 wt% EOC, 15 wt% LDPE, and 5 wt% HDPE is prepared in order to obtain a tunable multiple‐shape memory polymer with high strain storage capacity. It is found that depending on the programming procedure, this SMP obtains a dual‐, triple‐, or quadruple‐shape memory effect, with well‐defined intermediate temporary shapes (retraction < 0.5% K−1) over a significantly broad temperature range (up to 30 K), large storable strains (up to 1700%), and nearly full recovery of all shapes (>98.9%). A lightly cross‐linked blend of different polyethylenes (EOC, LDPE, and HDPE) is prepared to gain a network exhibiting a tunable multiple‐shape memory capability. The achieved material shows depending on the programming procedure a dual‐, triple‐, or quadruple‐shape memory, with well‐defined intermediate temporary shapes (retraction less then 0.5% K−1) over a significantly broad temperature range (up to 30 K), stored strains of up to 1700%, and excellent‐shape memory properties.