RSC Advances
·
2020
·Vol. 10
·期 72
·44323-44331
·
IF 3.119
Hanyu Xue,Xinzhong Li,Jianrong Xia,Qi Lin
Improving the adhesion between layers and achieving the recycling of resins are challenges in additive manufacturing (AM) technology. In this work, a new type of photo-reversible crosslinking resin based on polyvinyl alcohol (PVA) and coumarin (HMC) was prepared via grafting reaction. The critical idea was to create a coumarin based photo-reversible crosslinking resin by carefully tailoring the photo-crosslinking time and temperature, so that the resin could be extruded through the nozzle and then maintain the proper shape during UV-curing. Photo-reversible crosslinking of AM resin was realized without the use of monomers, photo-initiators or propagating. A reasonable irradiation time with 354 nm (crosslink) or 254 nm UV light (cleavage) of 10 min was critical for photo-reversible crosslinking of PVA-g-HMC at 120 °C. An important result of this work was that the developed photo-reversible crosslinked resin could be reused and the printed resin exhibits excellent adhesion properties, thermal conductivity and oxygen barrier performance.
研究领域:
材料科学
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化学工程
·
制造技术
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wen Wen Deng,Ze Ping Zhang,Min Zhi Rong,Ming Qiu Zhang
To impart processability and practical serviceability to organic room temperature phosphorescence (RTP) molecules, and address phase separation and rigid confinement environment of conventional RTP polymers, a small amount of Schiff base bonds crosslinked tetraphenylene luminescence networks are pinned to the borate ester bonds crosslinked epoxy networks producing reversible interlocked polymer networks-based halogen-free RTP material. By taking advantage of the conjugation interaction of Schiff base linkages, and phase separation inhibition/molecular confinement effects of the interlocking networks, excellent fluorescence quantum yield (up to 78.9 %), RTP lifetime (660 ms) and quantum yield (16.7 %) are achieved with ultra-low concentration of luminophores (0.05 wt%). Moreover, the resultant acquires decent tensile strength (3.8 MPa) and a high elongation-at-break (365 %) owing to its unique molecular design. The phosphorescence lifetimes (457 ∼ 602 ms) are only slightly affected even after cyclic stretching (at 50 % strain for 100 cycles), or soaking in water (for 30 days), or heating (90 °C). The built-in reversible covalent bonds and the topological network reorganization further enable injection molding and self-healing of the material. Having been repeatedly crushed/hot-pressed, the recycled material still shows RTP lifetime and quantum yield of 398 ms and 14.6 %, respectively. The present work provides a feasible approach to fabricate multifunctional robust organic phosphorescent materials with application prospects.
研究领域:
材料科学
·
化学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2019
·Vol. 7
·期 24
·3884-3893
·
IF 5.047
Yuancheng Liu,Fan Chen,Kui Zhang,Quan Wang,Yuanwei Chen,Xianglin Luo
Conventional cross-linked micelles may suffer from low drug loading efficiency, side effects or toxicity of residual cross-linkers and complicated preparation processes of drug-loaded micelles. Herein, pH-sensitive reversibly cross-linked micelles by phenol–yne click via curcumin (Cur) were developed by combining drug loading and cross-linking using poly(ethylene glycol)-b-poly(2-methacrylate ethyl 5-hexynoicate), (mPEG-b-PHEMA-5HA), as a drug delivery system. mPEG-b-PHEMA-5HA was synthesized by ATRP of 2-hydroxyethyl methacrylate (HEMA) using mPEG-Br as a macroinitiator and then by esterification with 5-hexynoic acid. mPEG-b-PHEMA-5HA could form micelles and the micelles could load Cur. Meanwhile, the Cur loaded micelles were readily cross-linked by a phenol–yne click reaction. The cross-linked micelles showed excellent stability after high dilution with water, and turned into smaller micelles under an acid environment (pH 5.0). The cross-linked micelles achieved a higher drug loading of Cur (17.81%, wt%) than the noncross-linked micelles, due to physical entrapment and chemical click reaction. Cur release from the Cur-cross-linked micelles was inhibited under physiological conditions (pH 7.4) but was faster at pH 5.0 in comparison with the noncross-linked micelles. The cross-linked micelles exhibited a superior antitumor activity with a lower IC50 of 4.86 and 9.6 μg mL−1 toward HeLa and 4T1 cells, respectively, resulting from effective internalization by tumor cells. In pharmacokinetics, the cross-linked micelles showed a prolonged circulation time, and thus exhibited more effective inhibition of tumor growth compared to free Cur and Cur loaded noncross-linked micelles in in vivo experiments. Therefore, pH-sensitive reversibly cross-linked micelles via Cur are promising as an antitumor drug delivery system.
研究领域:
药剂学
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肿瘤学
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生物材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 52
·32565-32572
·
IF 3.361
Wang Xiangjun,Xinzhong Li,Qi Lin,Jianrong Xia,Hanyu Xue
The need to improve the environmental friendliness and achieve the recycling of resins is an ongoing process for hot-melt adhesive technology. In this work, a new type of thermoreversible crosslinking hot-melt adhesive-based Diels Alder (DA) reaction was prepared. The critical idea was to efficiently initiate the esterification to yield furoic acid (FA)-grafted poly(vinyl alcohol) (PVA-g-FA), and then PVA-g-FA was mixed with N,N′-(4,4′-methylenediphenyl)dimaleimide (MDI) to finally obtain the thermoreversible crosslinking adhesive (PVA-g-FA/MDI). The experimental results indicated that the reversibility of the DA reaction between the furan rings and the maleimide groups allowed PVA-g-FA/MDI to be dynamically crosslinked. It was able to crosslink at a temperature of 80 °C and decrosslink at 120 °C. Moreover, the performances of hot-melt adhesive were investigated. The PVA-g-FA/MDI had a better peeling strength (43.33 N mm−1), bond strength (11.84 MPa), and thermal conductivity (0.263 W m−1 K−1) than PVA resins. The light-transmittance and haze value were 52.8% and 12.24‰, respectively. The PVA-g-FA/MDI resin could be reused more than two times.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Applied Materials Today
·
2022
·
IF 8.663
Sheng Jie Yuan,Zhong Quan Peng,Min Zhi Rong,Ming Qiu Zhang
To prepare oriented crosslinked liquid crystalline polymers (LCPs) while preventing the unwanted anisotropy, the authors fabricated interlocked networks from liquid crystalline epoxy and amorphous polyurethane, which are crosslinked by reversible Diels-Alder (DA) bonds and Schiff base, respectively. By making use of dynamicity of the reversible bonds as well as relative mobility of the parent networks of the interlocked networks, the material is subjected to stepwise solid-state bi-directional drawing. Owing to the directional alignment of the mesogens and molecular chains and the increased crosslinking density during stretching caused by the networks reshuffling, the strengths of the material in orthogonal directions are simultaneously improved and gradually converged to the values comparable to the reported highest level of unidirectionally orientated crosslinked LCPs. Furthermore, the biaxially oriented interlocked networks have inherited the intrinsic self-healing capability from the included reversible bonds. The proposed method is easy to use and expected to contribute to the practical applications of crosslinked LCPs, which is becoming more and more important in modern microelectronics and communication technology.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2020
·Vol. 11
·期 36
·5851-5860
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IF 5.342
Shuhui Liu,Xiaoyan Liu,Zongke He,Liying Liu,Hui Niu
Designing reversibly cross-linked polymer materials is of great importance for repeated processing. In this work, a Diels–Alder (DA) reaction between furan and maleimide was utilized to achieve thermoreversible cross-linking of ethylene/propylene rubber (EPR) by first constructing EPR with furyl pendent groups and then adding bismaleimide molecules as a cross-linking agent. The kinetics of the cross-linking reaction was detected using the rheological test, and the apparent kinetic rate coefficient (kCL) and Arrhenius activation energy (Ea, CL) of the cross-linking reaction were determined. By adjusting the furyl content of EPR and the molecular structure of the bismaleimide, the influence of the furan/maleimide ratio as well as the bismaleimide structure on the Ea, CL value was investigated, which might provide support for the efficient realization of reversible cross-linking in polymers and the repeated processing of materials via DA chemistry.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
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2013
·
IF 3.554
Weifeng Lin,Yueying He,Juan Zhang,Longgang Wang,Zhen Wang,Fangqin Ji,Shengfu Chen
Both blood stability and intelligent-responsiveness after reaching the drug-targeting site are very important features to make desirable nano-drug vehicles (NDVs). Here, a highly nonfouling cross-linked micelle based on a copolymer composed of carboxybetaine methacrylate (CBMA) as hydrophilic segment and 2-(methacryloyloxy)ethyl lipoate (MAEL) as hydrophobic and cross-linked segment is reported. Furthermore, a simple method to evaluate the hemocompatibility of NDVs through examining the activation of a blood-clotting protein (fibrinogen) was introduced. The micelles can encapsulate anticancer drug doxorubicin (DOX) conveniently and release DOX quickly in response to an intracellular reductive environment. With the advantages of excellent stability in fibrinogen (1 mg/mL) PBS solution and 50% fetal bovine serum (FBS), and accelerated intracellular drug release, the biocompatible zwitterionic micelles stabilized by reversible cross-linkage might be a promising drug carrier for cancer chemotherapy.
研究领域:
生物材料学
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药剂学
·
肿瘤学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 33
·20093-20100
·
IF 3.108
Ye Xiao,Huihua Huang,Xiaohong Peng
Polyurethanes can be modified to obtain an intrinsic self-healing property, which is the ability to self-recover from the damage of bulk materials, by changing the ways of increasing the density of hydrogen bonds or by inducing additional reversible crosslinks. An environment-friendly self-healing waterborne polyurethane (SHWPU) containing sulphonate groups was synthesized from isophorone diisocyanate, poly(tetramethylene glycol) and poly(1,4-butylene adipate glycol) and dispersed in water using the aliphatic diamine sulphonate as a hydrophilic chain-extender. The SHWPU coatings show a higher healing efficiency than the coatings without sulphonate group chains extended by ethylenediamine (EDA). With an increase in the soft contents, the healing efficiency increases, by virtue of which the polymer can completely recover itself at a temperature of 100 °C for 18 h. Moreover, significant phase separation of the continuous soft phase distributed with a spot-like hard phase is observed, which is due to the formation of ionic clusters.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Zheng Yue Wang,Yang You,Min Zhi Rong,Ming Qiu Zhang
The present study reports a facile method for gluing chemically different materials without pretreatment of their surfaces by in situ simultaneous formation of multiple interfacial adhesions and cohesion based on the concept of reversibly interlocked polymer networks (RILNs). As a demonstration of the design, the cross-linked polyacrylate containing reversible boronic ester bonds (SN-PA) and cross-linked polyurethane containing reversible disulfide bonds (SN-PU) are stacked and then sandwiched between the target adherends, glass, and fluoropolymer encapsulated polyethylene terephthalate (TPT). Besides, zirconium ions are incorporated into SN-PU in advance. Under hot compression, the two types of reversible covalent bonds are triggered and the temporarily de-cross-linked hydrophilic SN-PA and hydrophobic SN-PU are able to well wet glass and TPT, respectively, and interdiffuse across the SN-PA/SN-PU boundary. During the subsequent cooling, hydrogen bonds and coordination bonds are built up at the polymer/adherend interfaces, while RILNs are produced between SN-PA and SN-PU so that the peeling strength of the bonded glass/TPT assembly achieves 38.94 N/cm, which is higher than the values reported so far.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 35
·4789-4800
·
IF 4.76
Zongke He,Hui Niu,Nan Zheng,Shuhui Liu,Yang Li
A series of elastomeric hydrogels with repeated processability were prepared in this work. These hydrogels were obtained by cross-linking of two common polymers, poly(ethylene-co-propylene) (ethylene-propylene rubber, EPR) and poly(ethylene glycol) (PEG), via dynamic covalent bonds, specifically, through firstly furyl functionalization of EPR at the side groups and maleimide modification of PEG at the chain ends, and followed by the Diels–Alder reaction between furan and maleimide to construct thermoreversible EPR–PEG networks. The composition and microstructure of the network were adjustable in a wide range by facilely tuning the PEG feeding ratios and molecular weights (as the cross-linking agent). In the network the crystalline PEG and the elastic EPR endowed the material with strength and toughness respectively in the dry state, giving a fracture strength of 4–6 MPa and elongation at break of up to 380%; meanwhile, due to the hydrophilicity of PEG, the network could absorb water and form hydrogels, in which the hydrophobic EPR elastomer enhanced the hydrogels effectively. By tailoring the amount and the chain structure of the PEG moiety, the water absorption of the copolymer could reach as high as 356% in 1 hour, and the hydrogel elongation at break could achieve ∼400%, which was comparable to that of pristine cross-linked EPR. The material displayed low cytotoxicity in MC3T3-L1 cells and was biocompatible.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2019
·Vol. 11
·期 2
·337-343
·
IF 4.76
Jirui Wei,Jing Sun,Xu Yang,Sifan Ji,Yuhan Wei,Zhibo Li
Photoresponsive polymers have been receiving tremendous attention for many applications. Here, we report a new family of photoresponsive polypeptoid-based diblock copolymers PEG-b-poly(N-(S-(o-nitrobenzyl)-thioethyl) glycine) (PEG-b-PNSN) by ring-opening polymerization (ROP). The polymerization is well-controlled and a series of copolymers have been obtained with narrow polydispersity. We demonstrate that the cleavage degree of the o-nitrobenzyl (NB) group can reach 73% with the irradiation time increasing up to 6 hours. To the best of our knowledge, this is the first example of photoresponsive polypeptoids prepared by ROP. Depending on the chain length of PNSN, the PEG-b-PNSN diblock copolymers can self-assemble into various morphologies, including spheres, short cylinders and vesicles. More importantly, the thiol groups generated by UV-irradiation can be spontaneously oxidized into disulfide bonds, which behave as cross-linkers to stabilize the nanostructures with constant morphologies. Furthermore, this oxidation process is reversible in the presence of the reductive reagent glutathione (GSH), resulting in reversible self-crosslinking assemblies. The obtained photoresponsive polypeptoid copolymers are ideal candidates for smart polymeric materials in applications of nanomedicine and nanotechnology.
研究领域:
材料科学
·
生物医学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Yue-hong Zhang,Meng-jiao Zhai,Lei Shi,Qin-yang Lei,Shu-tong Zhang,Lei Zhang,Bin Lyu,Shun-hua Zhao,Jian-zhong Ma,Vijay Kumar Thakur
Vitrimers with reversible cross-links are emerging promising sustainable materials with reprocessability and recyclability. Here, castor oil-based epoxy resin (EMCO) with epoxy group and carbon-carbon double bonds was prepared through a two-step process and then cured with itaconic acid (IA) through epoxy-acid ring-opening reaction and free radical polymerization to fabricate fully bio-based epoxy vitrimers containing reversible transesterification bond. The thermal-mechanical properties, reprocessability, repairability, and recyclability could be balanced by varying the molar ratio of EMCO to IA. When the carboxyl group/epoxy group molar ratio reached 1.0, the EMCO-IA 1.0 vitrimer exhibited the highest tensile strength of 14.39 MPa and T g of 52.95 °C. Moreover, the vitrimer can be effectively remodeled (2 h at 180 °C) to prepare films and self-healing thanks to a rapid and mild stress relaxation process (2.56 min at 110 °C) and low activation energy (60.94 kJ·mol −1 ). More significantly, EMCO-IA vitrimer could be degraded in ethanol solution and recycled to prepare films and also exhibited excellent UV blocking ability. Overall, the EMCO-IA vitrimer can achieve a highly efficient closed-loop recycling without significantly sacrificing the mechanical properties, which can extend the service life and facilitate the sustainable development of the castor oil-based polymeric material.
研究领域:
材料科学
·
可持续发展
✓ 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）