Polymers
·
2024
·Vol. 16
·期 9
·1262
·
IF 4.7
Peng Wang,Zhuochao Wang,Wenxin Cao,Jiaqi Zhu
Transparent polysiloxane elastomers with good self-healing and reprocessing abilities have attracted significant attention in the field of artificial skin and flexible displays. Herein, we propose a simple one-pot method to fabricate a room temperature self-healable polysiloxane elastomer (HPDMS) by introducing dynamic and reversible imine bonds and boroxine into polydimethylsiloxane (PDMS) networks. The presence of imine bonds and boroxine is proved by FT−IR and NMR spectra. The obtained HPDMS elastomer is highly transparent with a transmittance of up to 80%. The TGA results demonstrated that the HPDMS elastomer has good heat resistance and can be used in a wide temperature range. A lower glass transition temperature (Tg, −127.4 °C) was obtained and revealed that the elastomer is highly flexible at room temperature. Because of the reformation of dynamic reversible imine bonds and boroxine, the HPDMS elastomers exhibited excellent autonomous self-healing properties. After healing for 3 h, the self-healing efficiency of HPDMS reached 96.3% at room temperature. Moreover, the elastomers can be repeatedly reprocessed multiple times under milder conditions. This work provides a simple but effective method to prepare transparent self-healable and reprocessable polysiloxane elastomers.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Fanghui Wang,Zhaonan Sun,Hanfei Zhang,Hong Zhu
A series of SEBS-C6-PIP-yPTP (y = 0–15%) AEMs with good mechanical and chemical stability were prepared by combining the strong rigidity of p-triphenyl, good toughness of SEBS, and excellent stability of PIP cations. After the introduction of a p-triphenyl polymer into the main chain, a clear hydrophilic–hydrophobic phase separation structure was constructed within the membrane, forming a continuous and interconnected ion transport channel to improve ion transport efficiency. Moreover, the molecular chains of the cross-linked AEMs change from chain-like to network-like, and the tighter binding between each molecule increases the tensile strength. The special structure of the six-membered ring makes PIP have a significant constraint effect; when nucleophilic substitution and Hoffman elimination occur at the α and β positions, the required transition state potential energy increases, making the reaction difficult to occur and improving the alkaline stability of the polymer membrane. The SEBS-C6-PIP-15%PTP membrane has the best mechanical properties (Ts = 38.79 MPa, Eb = 183.09% at 80 °C, 100% RH), the highest ion conductivity (102.02 mS. cm–1 at 80 °C), and the best alkaline stability (6.23% degradation at 80 °C in a 2 M NaOH solution for 1400 h). It can be seen that organic–organic covalent cross-linking is an effective means to improve the comprehensive performance of AEMs.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2021
·Vol. 29
·期 1
·1-11
·
IF 3.097
Li Kaiqi,Chen Long,Xiong Zuochun,Xiong Chengdong,Chen Dongliang
Amino-functionalized six-membered cyclic carbonate tert-butyl(2-oxo-1,3-dioxan-5-yl) carbamate (TBC) was synthesized with tert-Butyloxycarbonyl (Boc) as protected group. Due to its thermal properties, ring-opening polymerization (ROP) carried out in a relatively low temperature, and Sn (Oct) 2 as catalyst. A series of copolymers were prepared with L-lactide (LA), ε-Caprolactone (CL) as co-monomers, searching for proper components and ratios. The protecting Boc-group was easy to remove by using trifluoroacetic acid (TFA). The structures of TBC and copolymers were confirmed by 1 H NMR and 13 C NMR analysis. Copolymers were characterized by DSC, GPC and water contact angle analysis. The introduction of pendant amino groups resulted in a significant enhancement of hydrophilicity of the copolymers.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Environmental Chemistry Letters
·
2024
·
IF 15
Zhang Shuai,Ma Jingjing,Liu Xiangjun,Ma Yayun,Wang Junqi
Pyrolysis of modern biomass is a sustainable technique to produce chemicals, yet efficient and selective conversion remains challenging. We studied biomass pyrolysis catalyzed by graphene oxide for the production of levoglucosan, a chemical with potential applications in biodegradable plastics and surfactants. We tested model compounds containing 40–100 wt% cellulose, poplar biomass, and we modelled the role of graphene oxide by calculations using the density functional theory. Results for model compounds show that levoglucosan production is higher for compounds containing less than 50% cellulose. By contrast, levoglucosan yield are reduced for model compounds having more than 60 wt% cellulose, because graphene oxide induced the breakdown of levoglucosan. Experiments show that pyrolysis of poplar biomass with 5 wt% graphene oxide increased about three times the yield of levoglucosan, compared to non-catalyzed pyrolysis. Enhanced levoglucosan formation is explained by the formation of a six-membered ring intermediate.
研究领域:
能源科学
·
催化化学
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产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2025
·
IF 3.1
Xueqian Zhang,Jiasong Yan,Shuai Yuan,Shanqing Yu,Qingyu Liu,Xikai Wang,Rui Li
Whether cycloalkanes undergo six- or five-membered ring-opening reaction pathways remains controversial. In this work, the catalytic cracking reactions of cyclohexene and 1-methylcyclopentene, as model compounds, were investigated in a pulse microreactor. The characteristics of the reactions of the two model compounds were compared in terms of isomerization, cracking, and hydrogen transfer reaction, and the reasons for the differences in their catalytic reactions were analyzed in combination with thermodynamic and molecular simulation calculations. The results have shown that the catalytic cracking product distributions of cyclohexene and 1-methylcyclopentene were similar owing to their easy mutual isomerization; the five-membered ring-opening cracking pathway was more thermodynamically advantageous than that of six-membered ring-opening cracking, and therefore, the yield of the ring-opening cracking product of 1-methylcyclopentene was comparatively higher; the main products of the hydrogen transfer reaction of the two compounds were alkanes and aromatic hydrocarbons. By comparing the product distributions and reaction activation energies, the ring-opening reaction pathways were clarified, and the catalytic cracking reaction networks of cyclohexene and 1-methylcyclopentene were established.
研究领域:
化学
·
催化反应
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2016
·Vol. 45
·期 16
·7124-7130
·
IF 4.177
Li-Jun Zhang,Yan-Yan Li,Peng-Fei Liu,Ling Chen
New borophosphates Li3Cs2M2B3P6O24 (M = Pb, Sr) have been synthesized by high-temperature solid-state reactions. The single-crystal X-ray diffraction data reveal their non-centrosymmetric cubic space group P213 and lattice parameters of a = 12.7246(3) Å and 12.687(2) Å and V = 2060.31(8) Å3 and 2042.3(4) Å3 for Li3Cs2Pb2B3P6O24 and Li3Cs2Sr2B3P6O24, respectively. They are three-dimensional (3D) [BP2O8]3−∞ anionic frameworks formed by a new double six-membered ring building unit consisting of BO4 and PO4 units joined alternately. Interestingly, such a double six-membered ring is regarded as the structural variation of the 12-membered ring in the known KSrBP2O8, fusing at the BO4 tetrahedron induced by the coexistence of the Li+ and Cs+ cations with their large size difference. The title compounds show weak SHG intensity and exhibit photoluminescence emissions at 410 nm for Li3Cs2Pb2B3P6O24 and 440 nm for Li3Cs2Sr2B3P6O24.
研究领域:
材料科学
·
晶体学
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产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2019
·
IF 4.85
Yi-Gang Chen,Meiling Xing,Yao Guo,Zheshuai Lin,Xiujun Fan,Xian-Ming Zhang
Beryllium (Be) has high ionization energy (9.32 eV) with the greatest degree of covalency in the group IIA elements, and BeO4 tetrahedra (and BeO3 triangles) with covalent character are generally presented in beryllates. An unprecedented BeO6 trigonal prism with ultralong Be–O bonds as well as a BeO4 common tetrahedron is discovered in a new deep ultraviolet crystal Li13BeBe6B9O27 (LBeBBO) with a ∞2[Be6B9O33] double-layer framework. The BeO6 unit and its bond character are verified by an isostructural crystal Li13(Mg0.45Be0.55)Be6B9O27, while the orbital theory and charge density difference further clarify the ionic character of the BeO6 unit. Phonon dispersion confirms the structural stability of LBeBBO.
研究领域:
材料科学
·
晶体学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2016
·
IF 2.265
Mengmeng Zuo,Mingdong Zhou,Dianwen Hu,Fan Gao,Sijie Dong,Liangliang Huang
A new inorganic–organic hybrid indium phosphite-oxalate, formulated as H[In 5 (HPO 3 ) 6 (H 2 PO 3 ) 2 (C 2 O 4 ) 2 ]·(C 4 N 2 H 11 ) 2 ·H 2 O 1 has been hydrothermally synthesized in the presence of piperazine acting as a structure directing agent (SDA). The single crystal X-ray diffraction reveals that compound 1 shows three-dimensional open-framework with intersecting 12-ring channels along the [010] and [001] directions, which is constructed from strictly alternating double 6-ring units (D6Rs), [C 2 O 4 ] 2− groups and [H 2 PO 3 ] − pseudo-pyramids. It is noted that the classical D6R SBU is firstly reported in main metal phosphite/phosphite-oxalate. By regarding D6R as the 6-connected nodes, the inorganic–organic hybrid framework is based on a pcu-type topology. The as-synthesized product was characterized by single-crystal X-ray diffraction, powder X-ray diffraction, IR spectroscopy , thermogravimetric analysis (TGA), ICP-AES and elemental analyses.
研究领域:
材料化学
·
晶体学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Mingyu Shi,Chen-Yu Shi,Qi Zhang,Da-Hui Qu
Replacing the “inert” chemical bonds in traditional materials with dynamic bonds brings opportunities in designing renewable materials that repair, reprocess and recycle. Despite the many efforts made in covalent adaptable networks by elaborating a single type of dynamic covalent chemistry, the fabrication of double dynamic covalent polymeric networks, especially using simple small-molecule building blocks, still remains challenging. Here we report the solvent-free construction of a thermosetting material by combining 1,2-dithiolane-based reversible polymerization and dynamic covalent boroxine chemistry as crosslinkers. The resulting materials exhibit tunable mechanical properties, mechanical reprocessability, shape memory ability and closed-loop chemical recyclability. Quantitative kinetic analysis reveals the temperature-dependent apparent activation energy for the bond exchange of the resulting network as a result of the simultaneous integration of the two dynamic covalent bonds. Meanwhile, the boroxine units also act as a luminescent center to enable an emissive “organic glass” that can be used as a dual encryption material taking advantage of the reprogrammable shape-memory behavior of the dynamic network. Benefitting from the simple design, tunable variables and multi-functions, we envision that this double dynamic chemistry offers a robust scaffold and great chemical spaces for the design of dynamic polymeric materials.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2023
·
IF 5.1
Yi Yang,Rui Yang,Yu Liu,Zhenhao Yao,Qian Chen,Kan Zhang
A facile approach to incorporate an intramolecular 6-membered ring hydrogen bond into a benzoxazine monomer containing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) moiety has been developed, leading to a novel monobenzoxazine, ODOPB-pa . This monobenzoxazine was successfully synthesized via a Mannich condensation from 2-(6-oxido-6 H -dibenz-[ c , e ][1,2]oxaphosphorin-1,4-dihydroxy phenylene (ODOPB), propargylamine and paraformaldehyde. The newly obtained ODOPB-pa possesses a relatively lower polymerization temperature than most commercialized benzoxazine resins. In addition, the intramolecular 6-membered ring hydrogen bond is identified as an essential feature in its polymerization behavior. The cured product, poly(ODOPB-pa) , exhibits high thermal stability with a 5% weight loss temperature of 327 °C, and good flame retardant properties with a heat release capacity value of 119 Jg −1 K −1 and a total heat release value of 41 kJg −1 . Moreover, ODOPB-pa was also applied to mix in different amounts (5, 10, 15 and 20 wt%) with a tri-functional benzoxazine bearing propargyl group, TH-pa. Notably, it has been demonstrated that the TH-pa/ODOPB-pa blend derived thermoset with 10 wt% ODOPB-pa exhibits the best thermal and flame retardant properties in consideration of the high glass transition temperature (312 °C) and very low heat release capacity value (56.5 Jg −1 K −1 ). These combined advantages highlight the potential of intramolecular 6-membered ring hydrogen bond-containing ODOPB-based benzoxazine in the producing of high-performance thermosetting systems.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2024
·
IF 4
Lei Zhang,Baicheng Feng,Shibo Pang,Huifen Xin,Kun Li,Yan Jin
Six N‑hydroxy-5-norbornene-2,3-dicarbonylimine sulfonates(3a-3f) were created in this paper and produced as non-ionic photoacid generators (PAGs) in good yields. 1 H NMR and 13 C NMR were used to confirm the structures of the compounds and 19 F NMR was used to further justify the structure of 3a. Thermal Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) showed that all six PAGs have good thermal stability. Additionally, the solvent's influence on PAG compounds was examined using Ultraviolet and visible spectrum (UV–vis) and 254 nm fluorescence spectra (FS). The changes in the six PAG components of the products were monitored by HPLC on exposure to UV light (254 nm). An exposure acid production assay based on the spectrophotometric approach was developed using Rhodamine B (RB) as the acid sensor. The degradation and acid production quantum yields of the six PAGs were tested, and the results showed that all PAGs exhibited a high acid-producing capacity. In addition, we present a potential mechanism for the photogeneration of sulfonic acid, and DFT time calculations using Gaussian calculations support the N O bond cleavage mechanism of PAG 3c.
研究领域:
材料科学
·
化学合成
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2024
·
IF 6.5
Yinghu Song,Guojun Song,Jialiang Li,Xirui Yang,Zhaoji Li,Xiaoru Li
Developing elastomers with both high mechanical strength and reparability remains a formidable challenge. In this work, asymmetric six-membered ring structures and long side chain structures were introduced into the molecular main chain and side chain, respectively. This caused the hard domains within the molecular chain to be loosely packed, forming asymmetric dynamic hard domain structures. At the same time, multi-level asymmetric hydrogen bond structures were formed between molecules. The structure and properties of the materials were characterized and tested using infrared spectroscopy, mechanical property testing, dynamic mechanical analysis, and contact angle measurement. The experimental results showed that the resulting polyurethane elastomer exhibited strong tensile strength, reaching up to 54.4 MPa, excellent elongation at break (648 %), and good self-healing efficiency (87.8 %). Additionally, using interfacial composite technology, hydrophobically modified TiO 2 nanoparticles were compounded with polyurethane to prepare a super-hydrophobic surface coating with a contact angle of up to 160°. This coating demonstrated excellent acid and alkali resistance, wear resistance, and water droplet impact resistance. The multifunctional composite materials prepared in this study have broad potential applications in the fields of coatings and flexible hydrophobic films.
研究领域:
材料科学
·
高分子化学
·
表面科学
✓ 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）