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Ran Yu

Bio: Ran Yu is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Epoxy & Self-healing hydrogels. The author has an hindex of 11, co-authored 24 publications receiving 458 citations.

Papers
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TL;DR: In this paper, a type of polyurethane elastomer with excellent self-healing ability has been fabricated through digital light processing 3D printing, which is a new technique for 3D printings.
Abstract: A type of polyurethane elastomer with excellent self-healing ability has been fabricated through digital light processing 3D printing. First, a type of polyurethane acrylate containing disulfide bo...

155 citations

Journal ArticleDOI
TL;DR: A type of epoxy-acrylate hybrid photopolymer was synthesized and applied to fabricate shape memory polymers through a stereolithography 3D printing technique, proving its high shape fixity ratio, shape recovery ratio, and excellent cycling stability.
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%,...

122 citations

Journal ArticleDOI
Xiao Wu1, Xin Yang1, Ran Yu1, Xiaojuan Zhao1, Ying Zhang1, Wei Huang1 
TL;DR: In this article, a stiff epoxy vitrimer based on siloxane equilibration has been fabricated in a simple way in which a polysiloxane oligomer containing aminopropyl side groups and catalytic potassium silanolate end groups was synthesized and used as a curing agent.
Abstract: A new high performance stiff epoxy vitrimer based on siloxane equilibration has been fabricated in a simple way in which a polysiloxane oligomer containing aminopropyl side groups and catalytic potassium silanolate end groups was synthesized and used as a curing agent. The viscoelastic properties of the cured epoxy can be controlled by varying the concentration of potassium silanolate groups and the vitrimer possessing a complete stress relaxation behavior can be prepared, with relaxation times ranging from 376.8 s at 90 °C to 40.2 s at 170 °C. Due to the dynamic siloxane equilibration of polysiloxane catalyzed by potassium silanolate groups, this epoxy vitrimer exhibits excellent self-healing and recycling abilities. It can self-repair with a high healing efficiency, and be recycled at 130 °C within 40 min, retaining its original mechanical and thermal properties after at least four recycling cycles. Furthermore, such a material exhibits simultaneously a high service temperature (a glass transition temperature of 83 °C and an initial degradation temperature of 358 °C) and a strong (a stress at break of 46.6 MPa) and stiff (Young's modulus of 2.2 GPa) nature.

120 citations

Journal ArticleDOI
TL;DR: In this article, a polyurethane acrylate is successfully synthesized and then compounded with epoxy and isobornyl acrylated as well as radical photoinitiator to get photopolymer.

98 citations

Journal ArticleDOI
TL;DR: A series of photosensitive resins suitable for the production of silicone elastomers through digital light processing 3D printing are reported, which have great potential applications in various fields, including soft robotics, flexible actuators, and medical implants.
Abstract: A series of photosensitive resins suitable for the production of silicone elastomers through digital light processing 3D printing are reported. Based on thiol–ene click reaction between a branched ...

72 citations


Cited by
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TL;DR: This Minireview summarizes commonly used powerful DCBs formed by simple, often "click" reactions, and highlights the powerful materials that can result.
Abstract: Dynamic covalent bonds (DCBs) have received significant attention over the past decade. These are covalent bonds that are capable of exchanging or switching between several molecules. Particular focus has recently been on utilizing these DCBs in polymeric materials. Introduction of DCBs into a polymer material provides it with powerful properties including self-healing, shape-memory properties, increased toughness, and ability to relax stresses as well as to change from one macromolecular architecture to another. This Minireview summarizes commonly used powerful DCBs formed by simple, often "click" reactions, and highlights the powerful materials that can result. Challenges and potential future developments are also discussed.

476 citations

Journal ArticleDOI
TL;DR: The concept of vitrimer is reviewed, their most unique properties are described, and the outlook on outstanding challenges that must be met are presented to realize vitrimers as a next generation solution for recyclable high performance materials.

286 citations

Journal ArticleDOI
TL;DR: Schiff base covalent adaptable networks (CANs) as discussed by the authors combine high performance, super-rapid reprocessability, excellent monomer recovery, and arbitrary permanent shape changeability as well as outstanding fire resistance.
Abstract: Conventional thermosets are built by nonrenewable fossil resources and are arduous to be reprocessed, recycled, and reshaped due to their permanent covalent cross-linking, and their flammability makes them unsafe during use. Here, for the first time, we synthesized a novel Schiff base precursor from abundant and renewable lignin derivative vanillin and produced malleable thermosets (Schiff base covalent adaptable networks (CANs)) combining high performance, super-rapid reprocessability, excellent monomer recovery, and arbitrary permanent shape changeability as well as outstanding fire resistance. The Schiff base CANs exhibited high glass transition temperatures of ∼178 °C, tensile strength of ∼69 MPa, tensile modulus of ∼1925 MPa, excellent flame retardancy with UL-94 V0 rating and V1 rating, and high LOI of ∼30%. Meanwhile, three Schiff base CANs showed high malleability with the activation energy of the bond exchange of 49–81 kJ mol–1 and could be reprocessed in 2–10 min at 180 °C. These Schiff base CAN...

212 citations