CELLULOSE
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2021
·Vol. 28
·期 5
·2879-2888
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IF 5.044
Li Chang,Ju Benzhi,Zhang Shufen
The synthesis of the first cellulose-based vitrimer is described. Dynamic ester bonds were responsible for the dynamic properties of carboxymethyl cellulose (CMC)-based vitrimer. The addition of suitable catalyst and glycerol in the vitrimer formulations was crucial for the reprocessability of these materials. Thermogravimetric and dynamic mechanical analyses tensile strength tests were performed to investigate the effect of the catalyst and glycerol on the thermal stability and mechanical properties of the materials. A minimum amount of 5 mol% of 1,5,7-triazabicyclo[4.4.0]dec-5-ene with respect to the carboxyl group content was required to maintain reprocessability by hot press. The CMC vitrimer exhibited good reprocessability and shape memory ability. Our work demonstrates that cellulose, the most abundant bio-resource on the planet, can be a promising raw material for bio-based vitrimer due to its excellent renewability and low cost. Graphic abstract
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
POLYMER
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2018
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IF 3.483
Xinxin Xia,Zijin Wu,Wanjie Wang,Yonggang Shangguan,Qiang Zheng
It is a challenge to develop advanced elastomers with a combination of high strength , stiffness and toughness by a relatively convenient and environmentally friendly approach. Herein, we reported a facile and environmentally friendly method to prepare hybrid crosslinked nitrile butadiene rubber (NBR) comprised of covalent and ionic bonds , and this hybrid crosslinked rubber possesses comprehensively improved mechanical properties , higher crosslinking density, deformation recovery and shape memory ability. The hybrid crosslinked NBR was prepared by incorporating 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and zinc oxide (ZnO) into NBR via internal milling together with dicumyl peroxide (DCP), and then vulcanization , which is a very simple and environmentally friendly method without extra procedure or treatment. The hybrid crosslinked network in NBR has randomly distributed covalent and ionic bond crosslinks, the strong covalent bonds serve as permanent crosslinks, imparting the elasticity, whereas the weak ionic bonds reversibly rupture and reform, dissipating the energy. Because of the restricting effect of ionic bonds on segmental movement, the hybrid crosslinked NBR shows higher glass transition temperature , lower loss factor peak value and longer relaxation time. By tuning the ionic bond strength via temperature, a much smaller range of linear viscoelastic region is observed for hybrid crosslinked NBR with high content of AMPS and ZnO at a relatively higher temperature, which endows the sample with shape memory ability. This design principle of incorporating ionic bonds to strengthen vulcanized NBR should be applicable to other diene rubber materials.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
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2021
·Vol. 306
·期 11
·2100370
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IF 4.367
Xin Qi,Enyun Xu,Manman Jia,Jichuan Zhang,Liqun Zhang,Dongmei Yue
At present, the synthesis of body temperature triggering shape memory polymers usually requires elaborate structural design, which limits their wide application. Herein, starting from bio-based Eucommia ulmoides gum (EUG), a series of EUG/silica hybrids (ESHs) are prepared through a facile one-pot process, in which EUG is epoxied and then self-crosslinked with SiO 2 by epoxy ring-open reaction. Varying the amount of H 2 O 2 , the shape memory transition temperature ( T trans ) of ESHs is adjusted to 47.4–36.6 ℃, which is close to human body temperature (37 ℃). Among them, ESH-17 exhibited the best body temperature triggering shape memory ability ( T trans = 36.6 ℃), which can restore the permanent shape within 60 s at 37 ℃ with a shape fixity ratio of 99% and shape recovery ratio near 100%. In addition, the shape memory mechanism is discussed and shows some application scenarios of ESHs. The as-produced materials can be used as smart biomaterials such as self-tightening sutures, self-sealing root canal filling materials, and so on.
研究领域:
材料科学
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生物学
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医学
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产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
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2021
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IF 8.528
Shuai Yang,Yang He,Jinsong Leng
Multi-stimuli selective actuation of shape memory polymers (SMPs) with multi memory capabilities have attracted great attention in recent years, due to diverse active deformation application scenarios. Current multi-SMPs with low T t , however, are faced with inherent barriers, such as low fixation and inaccurate control, because the shape retainability, controllability, and responsiveness of SMPs are highly determined by transition temperature (T t ). Herein, quadruple-shape memory poly(aryl ether ketone) (PAEK) with tunable high T t and selective response characteristics were successfully fabricated for the first time, which especially harnessed ultra-high programmability and controllability. More significantly, the quadruple shape memory PAEK-based smart architectures such as “fingers” and “flower” were demonstrated to exhibit the controllable multi-stages actions. Utilizing a “man” as an example, we put forward different programming routes up to ten to make it perform complex pre-set deformation actions. The quadruple shape memory PAEK of high T t possessed great utilizing potential in fields of soft robots , actuators, and deformable devices.
研究领域:
材料科学
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智能材料
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生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
Additive Manufacturing
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2021
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IF 10.998
Wenjie Li,Xiaopeng Cheng,Yuan Wang,Shanfeng Wang
Projection micro-stereolithography (PμSL) is an effective technique to rapidly fabricate porous scaffolds with complex structures of photo-crosslinkable polymer resins, which normally contain a reactive diluent and a photo-initiator. In previous reports on 3D printing of poly(propylene fumarate) (PPF) scaffolds, diethyl fumarate (DEF) was unavoidably used as a reactive diluent in the PPF resin. Here we present a photo-crosslinkable resin composed of PPF and hyperbranched polyester acrylate (HPA), which has multiple carbon-carbon double bonds to participate in photo-crosslinking as a reactive diluent, and PμSL 3D fabrication of tissue-engineering scaffolds using this resin. The structure and viscoelastic behavior of uncrosslinked PPF/HPA, and the gel fraction, thermal and mechanical properties of photo-crosslinked PPF/HPA samples have been investigated, in comparison with those of PPF/DEF. Blending HPA with PPF was found to decrease the viscosity of PPF and to expedite the photo-crosslinking process, both of which are important in formation of PPF networks. In addition, HPA can effectively enhance the stiffness and toughness of the fabricated network simultaneously. In PμSL 3D fabrication, the cure depth (C d ) experiments proved that the PPF/HPA resin had an extremely low critical energy (E c ) of 2.1 mJ/cm 2 , leading to ultra-fast curing when exposed to ultraviolet (UV) light. Our rapid prototyping characteristics are evident under the premise of ensuring high precision. For the PPF/HPA resin, the exposure time per layer was only 0.1–2 s, which at least doubled the printing speed compared with the other 3D fabrication techniques . At high printing resolution of 50 µm, an ultra-fast printing speed of 18 cm/h was achieved by using the PPF/HPA resin, while the value for the PPF/DEF resin was only 3.6 cm/h. Benefited from the better crosslinked networks, the fabricated PPF/HPA scaffolds exhibited a lower shrinkage, higher stiffness and toughness, and better recovery capacity than their PPF/DEF counterparts, indicating their 4D printing characteristics.
研究领域:
生物医学工程
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组织工程
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DOI
高影响因子
RSC Advances
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2022
·Vol. 12
·期 33
·21512-21519
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IF 4.036
Jiacheng Ma,Shifeng Wen,Zhufeng Yue
Although a wide range of self-healing materials have been reported by researchers, it is still a challenge to endow exceptional mechanical properties and shape memory characteristics simultaneously in a single material. Inspired by the structure of natural silk, herein, we have adopted a simple synthetic method to prepare a kind of elastomer (HM-PUs) with stiff, healable and shape memory capabilities assisted by multiple hydrogen bonds. The self-healing elastomer exhibits a maximum tensile strength of 39 MPa, toughness of 111.65 MJ m−3 and self-healing efficiency of 96%. Moreover, the recuperative efficiency of shape memory could reach 100%. The fundamental study of HM-PUs will facilitate the development of flexible electronics and medical materials.
研究领域:
材料科学
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
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2022
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IF 9.879
Xiaoming Qi,Yu Liu,Hongbo Dai,Yaofeng Zhu,Yubing Dong,Shao-Yun Fu,Qingqing Ni,Yaqin Fu
Soft and flexible mechanical actuators capable of demonstrating large deformations and outputting stress spontaneously in responding to external environmental stimuli have been becoming a research focal point in the field of smart biomimetic systems and devices. Here, a novel twisted yarn actuator consisting of shape memory zinc dimethacrylate/ethylene vinyl acetate (ZDMA/EVA) composite fibers has been created following a four-step fabrication protocol including two-roll milling, melt-spinning, ultraviolet crosslinking, and twisting procedures. The obtained ZDMA/EVA composite fibers demonstrate excellent thermomechanical coupling effect and superior thermal/mechanical stability. In specific, the twisted yarn actuators present strong two-way shape memory capability (up to 8% reversible tensile stroke) and outstanding recovery stress (1.63–1.82 MPa). Notably, this composite yarn actuator (in diameters of 438–719 μm) is able to afford tension loads about 2300 times heavier than its own weight, reaching 7.76% reversible strain and exhibiting an exceptional energy density of 210 J/kg that is 26 times higher than the typical skeletal muscles. In addition, the optimal yarn actuator displays an ultimate rotation speed and rotational energy density of 15456 rpm/m and 5439 J/kg, respectively. This experimental study presents a facile, low-cost, and environmental-friendly manufacturing approach of developing high performance composite fiber-based yarn actuators.
研究领域:
智能材料
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仿生系统
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
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IF 15.1
Kang Chen,Haoxin Zhu,Zhiyi Zhang,Yingqing Shao,Qianhui Yu,Xinlei Cao,Siyan Pan,Xin Mu,Zhenhua Gao,Di Wang,Shuangying Wei,Shuaiyuan Han
Self-healing coatings represent a promising advancement in intelligent materials, as they possess the ability to autonomously heal damage through a self-regeneration mechanism. However, a significant challenge is to strike a balance between the self-healing capability and mechanical performance under specific healing conditions, such as heat or light. This limitation hinders the application of self-healing coatings. This study describes a series of syntheses of a waterborne polyurethane (WPU) based on a vanillin-derived aromatic Schiff base (VASB). The VASB-WPU was created by incorporating dynamic reversible covalent bonds into the backbone chain and introducing supramolecular interactions (hydrogen bonds and ionic bonds) into the side chain. The VASB-WPU exhibits self-healing properties and vitrimer characteristics. By implementing a healing process that involves light and heat stimulation, the VASB-WPU exhibits an impressive healing efficiency of 92.43% in thin films while maintaining exceptional mechanical performance, with a tensile stress of 10.59 MPa and a toughness of 16.56 MJ/m 3 . Furthermore, the VASB-WPU coatings exhibit exceptional multiple shape memory capabilities and self-healing effects. When applied to wooden surfaces, the VASB-WPU coatings can achieve 100% self-healing of a 5 μm scratch at the interface in just 3 min of irradiation. A new method has been introduced for developing intelligent self-healing coatings for wood.
研究领域:
材料科学
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聚合物化学
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涂层技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）