Frontally polymerizable shape memory polymer for 3D printing of free-standing structures. (24th December 2021)

• Record Type: Journal Article
• Authors: An, Yongsan; Jang, Joon Hyeok; Youk, Ji Ho; Yu, Woong-Ryeol
• Is Part Of: Smart materials and structures. Volume 31:Number 2(2022)
• Publication Date: 2021-12-24
• Subjects: shape memory polymer -- frontal polymerization -- rheological properties -- 3D printing -- free-standing structure; Smart materials -- Periodicals; Strucural design -- Periodicals; 620.11
• DOI: 10.1088/1361-665X/ac41ea
• Languages: English
• ISSNs: 0964-1726

Abstract

Abstract: Four-dimensional (4D) printing is used to describe three-dimensional (3D)-printed objects with properties that change over time. Shape memory polymers (SMPs) are representative materials for 4D printing technologies. The ability to print geometrically complex, free-standing forms with SMPs is crucial for successful 4D printing. In this study, an SMP capable of frontal polymerization featuring exothermic self-propagation was synthesized by adding cyclooctene to a poly(dicyclopentadiene) network, resulting in switching segments. The rheological properties of this SMP were controlled by adjusting incubation time. A nozzle system was designed such that the SMP could be printed with simultaneous polymerization to yield a free-standing structure. The printing speed was set to 3 cm min −1 according to the frontal polymerization speed. A free-standing, hexagonal spiral was successfully printed and printed spiral structure showed excellent shape memory performance with a fixity ratio of about 98% and a recovery ratio of 100%, thereby demonstrating the 3D printability and shape memory performance of frontally polymerizable SMPs.