title: Three-Dimensional Printing of Shape Memory Composites with Epoxy-Acrylate Hybrid Photopolymer.
abstract: Four-dimensional printing, a new process to fabricate active materials through three-dimensional (3D) printing developed by MIT's Self-Assembly Lab in 2014, has attracted more and more research and development interests recently. In this paper, a type of epoxy-acrylate hybrid photopolymer was synthesized and applied to fabricate shape memory polymers through a stereolithography 3D printing technique. The glass-to-rubbery modulus ratio of the printed sample determined by dynamic mechanical analysis is as high as 600, indicating that it may possess good shape memory properties. Fold-deploy and shape memory cycle tests were applied to evaluate its shape memory performance. The shape fixity ratio and the shape recovery ratio in ten cycles of fold-deploy tests are about 99 and 100%, respectively. The shape recovery process takes less than 20 s, indicating its rapid shape recovery rate. The shape fixity ratio and shape recovery ratio during 18 consecutive shape memory cycles are 97.44 ± 0.08 and 100.02 ± 0.05%, respectively, showing that the printed sample has high shape fixity ratio, shape recovery ratio, and excellent cycling stability. A tensile test at 62 °C demonstrates that the printed samples combine a relatively large break strain of 38% with a large recovery stress of 4.7 MPa. Besides, mechanical and thermal stability tests prove that the printed sample has good thermal stability and mechanical properties, including high strength and good toughness.
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Ran
authors.identifier: http://orcid.org/0000-0001-6785-3209
authors.initials: R
authors.lastname: Yu
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.|University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wu
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.|University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Zhao
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Yulei
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
keywords: 3D printing; acrylate; epoxy; shape memory polymer; stereolithography