New progress in photocuring 4D printing research in Fujian

[ Instrument Network Instrument Development ] 4D printing technology is a new technology developed by combining 3D printing technology with intelligent material structure. The intelligent material structure is self-excited by the external environment on the basis of 3D printing to realize its structural changes over time. Three-dimensional objects add a time dimension. 4D printing technology can change the traditional "mechanical transmission + motor drive" mode, allowing objects to self-assemble in places that are difficult to reach in underground pipelines, spacecraft, human organs, etc. In 2016, it was listed as the next top ten technology to subvert the world. One of them has many application prospects in the fields of aerospace, electrical automation, robotics, textile materials, tissue engineering, medical devices, drug delivery carriers and the like.

Recently, the Wu Lixin team of the Institute of Physical Structures of the Chinese Academy of Sciences and the Key Laboratory of Functional Nanostructure Design and Assembly of the Chinese Academy of Sciences, for the first time reported the permanent shape with the support of the Ministry of Science and Technology’s national key R&D plan and the “One Three Five” key cultivation project of Haixi Institute. Reconfigurable 4D printed shape memory polymer, designed and synthesized a novel methacrylate monomer with aldehyde group (2-formylbenzoic acid 2-(methacryloyloxy)ethyl ester, MEFB And a hyperbranched siloxane crosslinker (HPASi) to form a (meth) acrylate system (IEMSis) with a dynamic imine bond for 4D printing. The flexible chain structure of HPASi significantly improves the toughness of IEMSis, which is about 33-97 times that before the addition. The cross-linking effect of HPASi also gave IEMSis good shape memory properties, and their shape fixing rate and shape recovery rate were 97.5-97.6% and 91.4-93.7%, respectively. At the same time, in the absence of catalyst and relatively mild conditions, IEMSis can achieve stress relaxation through the dynamic exchange of imine bonds, so that the permanent shape of 4D printing can be reconstructed under certain conditions, so it is expected to expand the application range of 4D printing technology. . Related research results are published in ACS Applied Materials & Interfaces (2019, DOI: 10.1021/acsami. 9b14145.). Postdoctoral Yan Jiatao is the first author of the paper. The research uses the equipment developed by Lin Wenxiong's team, and the results have been applied in Guorui Zhongke, a joint venture company of Haixi Institute.

Previously, the team made a number of important advances in 3D printing resin research based on 4D printing. Nanoparticle-reinforced thermoplastic 3D printing resin results published in Materials & Design (2016, 102, 276-283), has been cited 193 times, listed by the Elsevier Publishing Group as the magazine Most Cited Articles; nanoparticle enhanced light curing 3D Printed resin results were published in Composites Part A (2019, 117, 276-286) and Composites Part A (2016, 88, 234-242); rare earth magnetic 3D printing resin results published in the Journal of Alloys and Compounds (2017, 715, 146 -153); foamable 3D printing resin results published in Advanced Engineering Materials (2018, 20, 1800215) and Materials & Design (2016, 105, 152-159); and double-cure 3D printing resin researched in collaboration with Xu Ying team The system was published in the Journal of Materials Science (2019, 54, 5865-5876) and has received extensive attention from domestic and foreign counterparts.