JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 26
·48844
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IF 2.188
Guanjie Liu,Xuehong Wei,Ziwei Wang,Jianguo Ren
Polycarboxylic superplasticizers produced by polyether macromonomers have attracted widely attention recently. Polyether macromonomers can be divided into vinyl ether-based and vinyl alcohol-based macromonomers according to the starting agents (vinyl ether and vinyl alcohol, respectively). In this study, three vinyl ether-based macromonomers were synthesized to compare with vinyl alcohol-based macromonomers that commonly used at present. It was found that the three vinyl ether-based macromonomers all can be copolymerized at lower reaction temperature (5 °C) and shorter reaction time (30–45 min) when the same reaction conversion ratio was achieved. To better explain the high activity of vinyl ether-based macromonomers, the molecular structure of different polyether macromonomers was calculated. The results show that the electron cloud on the CC double bond of vinyl ether-based macromonomers exhibits more obvious deflection because of the direct connection with the oxygen atom, which makes it more easily to copolymerize with acrylic acid. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48844.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2021
·Vol. 61
·期 6
·1662-1672
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IF 2.428
Le Song,Xiulei Wang,Pengcheng Xie,Yumei Ding,Kaifang Dang,Weimin Yang
Single-polymer composites (SPCs) are promising composite materials in which the reinforcement and matrix have the same chemical composition. In situ polymerization shows a broad application potential for producing SPCs due to its wide temperature window. However, the dissolution of fiber reinforcements in the liquid monomer destroys the oriented chain structure of the fibers and affects the properties of SPCs. In this study, the polymerization time was adjusted by varying the activator dosage. The influence of the dissolution of fibers on the properties and the structure of SPCs was investigated. The maximum tensile strength was achieved at the highest activator dosage. A longer duration was required for the polymerization due to the low-activator dosage, which led to the destruction of the oriented chain structure and the formation of a large amount of oligomers on account of the dissolution. Eventually, SPCs showed a low strength and a high deformation at break. In order to realize a good reinforcing effect, a sufficiently large dissolution window must be created by reducing the polymerization time. This study enhanced our understanding of the structure–property relationships of SPCs and provided a way to improve their mechanical characteristics.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 34
·4974-4985
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IF 5.582
Yuejia Zhu,Luoyu Gao,Zhenjiang Li,Bo Liu,Zhihao Zhang,Haoying Tong,Yuanyuan Qu,Yusheng Quan,Xin Zou,Kai Guo
Olefin monomers are divided into cationically polymerizable ones (monomer A, such as vinyl ethers) and radically polymerizable ones (monomer B, such as acrylates); in parallel, cyclic ester monomers are polymerizable either electrophilically (monomer C, such as lactones) or nucleophilically (monomer D, such as lactides). To address the challenge of polymerizing the distinctive four types of monomers in one pot into ABCD type tetrablock copolymers, we proposed a bifunctional reversible addition–fragmentation chain transfer (RAFT) agent bearing both the RAFT polymerization site and ring-opening polymerization (ROP) site. The RAFT site was able to copolymerize A and B via switching the cationic RAFT polymerization (cRAFT) to radical RAFT polymerization (rRAFT). Subsequently, the ROP site copolymerized C and D by switching the electrophilic ROP to nucleophilic ROP. A general dual-switch strategy of both RAFT and ROP mechanism transitions successfully produced ABCD-type tetrablock quaterpolymers in one pot by sequential monomer feeding. Poly(isobutyl vinyl ether)-b-poly(methyl methacrylate)-b-poly(δ-valerolactone)-b-polylactide (PIBVE-b-PMMA-b-PVL-b-PLA) was synthesized. All synthesized homopolymers and multi-block copolymers exhibited predicted molecular weights and relatively narrow dispersities (Đ ≤ 1.45). The copolymerization strategy paved a new avenue to combine cRAFT, rRAFT and ROPs to copolymerize vinyl and cyclic ester monomers for rational design and precise synthesis of multiblock copolymers with advanced architectures and functionalities.
研究领域:
高分子化学
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材料科学
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高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2015
·Vol. 31
·期 1
·160-166
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IF 0.875
Zuo Huajiang,Wen Wanhua,Wu Dingcai,Fu Ruowen,Tang Chunyi
Copolymers of quaternary ammonium monomer(QAM) and hydrophilic co-monomer were successfully synthesized by free radical polymerization. It was discovered that the hydrophilic co-monomers with poor antibacterial activity significantly enhanced the activity of QAM substituted with a long alkyl chain[ i.e. , N , N -dimethyl- N -dodecyl methacrylate ammonium bromide(DMAEMA-DB)]. When a suitable molar ratio of DMAEMA-DB to co-monomer was selected, the activity of the copolymers was up to 123 times that of the homopolymer of DMAEMA-DB against S. aureus , and 282 times that of it against E. coli . But unlike DMAEMA-DB, the co-monomers might weaken the activity of QAM substituted with a short alkyl chain[ i.e. , N , N -dimethyl- N -butyl methacrylate ammonium bromide(DMAEMA-BB)]. Moreover, it was found that copolymers of DMAEMA-DB were much more biocidal than those of DMAEMA-BB. Therefore, it could be speculated that the long alkyl chain plays an important role in the antibacterial activity, and that the hydrophilic co-monomers are beneficial to polymeric guaternary ammonium compounds(PQACs) to exert the positive effect of the long alkyl chain to the greatest degree.
研究领域:
高分子化学
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微生物学
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材料科学
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DOI
高影响因子
Polymer Chemistry
·
2018
·Vol. 9
·期 20
·2830-2842
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IF 4.927
Mo Zhu,Nairong Hao,Jinxian Yang,Lianwei Li
V-type (B∼∼A∼∼B) and Y-type (A∼∼∼∼B2) macromonomer approaches are two of the most widely adopted synthetic methodologies for the preparation of long-subchain hyperbranched polymers (LHPs) with a controlled subchain length. However, little attention has been paid to the difference of the structural regularity of hyperbranched polymers prepared via the two approaches in previous related studies. This work aims to elucidate how these two synthetic approaches quantitatively influence the polymerization, branching pattern and solution properties of the prepared hyperbranched polymers. First, two sets of model hyperbranched polystyrenes (HPSV and HPSY) were prepared from V-type and Y-type macromonomers by a combination of atom transfer radical polymerization (ATRP) and azide–alkyne cycloaddition coupling reaction, respectively. The intrachain cyclization study indicated that the macromonomer self-cyclization during the interchain coupling process was strongly affected by the chain length and the structure of the used macromonomer as well as the reaction concentration. The V-type macromonomer was found to be less inclined to undergo interchain coupling due to the stronger steric hindrance effect. Furthermore, via triple-detection size exclusion chromatography (TD-SEC) characterization, the intrinsic viscosity ([η]) and the radius of gyration (Rg) were found to be scaled to the molar mass of the macromonomer (Mm) and the molar mass of the entire chain (Mt) as [η] = KηMtνMmμ (μ ≃ 0.25 and ν ≃ 0.40) and Rg = HRMtαMmβ (α ≃ 0.47 and β ≃ 0.083) for both HPSV and HPSY samples. These scaling relationships evidenced that both HPSV and HPSY hyperbranched structures hold a similar statistically fractal feature. More importantly, the determined values of ratios Kη,Y/Kη,V (∼1.5) and HR,Y/HR,V (∼1.2) demonstrated, for the first time, that the average equivalent length of the branching subchain (Ls) for HPSY is much longer than the initial macromonomer chain length (Lm), i.e. Ls = 2.5Lm while Ls is exactly equal to 1/2Lm for HPSV. This finding clearly clarified the difference between Ls and Lm, and thus the terms of Ls and Lm should not be misused in the future structure–property study. Finally, the value of the Rg/Rη ratio is determined to be ∼1.05 and ∼1.15 for HPSV and HPSY samples (Rη: viscometric radius), respectively, which are much smaller than the typical values for linear chains in good solvents (1.20–1.40), revealing the less draining nature of these hyperbranched structures.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2022
·Vol. 46
·期 35
·16781-16788
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IF 3.925
Jin Wang,Yuanlu Wang,Bingchen Liu,Tao Fu
A bifunctional diethylene glycol difuran acrylate (DEFA) and a trifunctional trimethylolpropane trifuran acrylate (TMFA) monomer for solid-state photopolymerization were synthesized from a biomass material, furfural. High molar extinction coefficients in the order of 104 indicate the good UV absorption properties of both monomers. The photopolymerization kinetics studies show that DEFA achieves a maximum polymerization rate (Rp) in 54 s and TMFA in 35 s without photoinitiators, and the maximum double bond conversion (DBC) reached 88% for DEFA and 78% for TMFA, which proves that they have high photosensitivity. The addition of the 2,4-dinitroaniline sensitizer increases the maximum DBC, but increases the maximum Rp markedly. The high crystallinity of DEFA and TMFA is prone to photodimerization and forms an amorphous polymer. Both the linear polyester from DEFA and the crosslinked polyester from TMFA have good thermal oxidation stability. Therefore, we developed a strategy to produce highly sensitive monomers for the application of photosensitive materials that polymerize quickly without photoinitiators and solvents.
研究领域:
材料科学
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有机化学
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DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2015
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IF 3.453
Shengxue Wang,Wei Li,Song Wang,Jinming Jiang,Zhaohui Chen
Hierarchical porous lanthanum zirconate (La 2 Zr 2 O 7 , LZO) monoliths have attracted numerous attentions as adsorption, catalysis, especially in high-temperature and high water-vapor-containing environments. Herein, La 2 Zr 2 O 7 monoliths with hierarchially distributed pores have been synthesized via a spontaneous route based on a non-alkoxide sol–gel process accompanied by phase separation. Nitrates of Zr(IV) and La(III) were used as precursors, propylene oxide and formamide were used as gelation inducers, and polyethylene glycol was used as phase separation inducer. The mechanisms of Zr(IV)/La(III) binary gelation process and competitive reaction between gelation and phase separation have been discussed. Zr(IV)/La(III) binary gels exist in the form of Zr(IV)-rich gel networks coupled with La(III)-rich discrete entities. The size of the pores can be controlled by adjusting the amount of gelation and separation inducers. The surface area of the as-prepared La 2 Zr 2 O 7 monoliths is 89 m 2 /g. La 2 Zr 2 O 7 monoliths are amorphous and heating in air at more than 600 °C leads to the formation of pyrochlore structure La 2 Zr 2 O 7 . With further increase in temperature, the crystalline degree of LZO monoliths increased. After heat treatment, the macroporous skeleton can be well retained. However, the macropores became slightly smaller and the solid skeleton became fragile. Sintering of the continuous skeleton occurred after heat treatment.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Haoran Liu,Chenghao Wang,Lishuai Zong,Lingmei Jiang,Guangsheng Zhang,Zichun Ding,Zexian Jia,Changhong Xiao,Chao Li,Jinyan Wang,Xigao Jian
Currently, drop-on-demand (DOD) inkjet-printed dielectric inks used to produce next-generation high-frequency electronic devices fail to meet the requirements of circuit board substrates in terms of thermal, mechanical, and dielectric properties. To address this gap, we synthesized a low-viscosity acrylate monomer featuring an intrinsically low dielectric structure (hexafluorobisphenol A) and multiple cross-linking sites, and a benzocyclobutene monomer with low curing shrinkage and excellent thermomechanical properties. By mixing these monomers with other reactive diluents and verifying them through theoretical calculations and printing, we have developed a range of dielectric inks suitable for inkjet 3D printing. To enhance the overall performance of the cured inks, a sequential UV/thermal curing strategy was employed to form interpenetrating networks (IPNs). The optimal ink formulations met the requirements of circuit board substrates, demonstrating excellent heat resistance (T d5% = 334 °C, T g = 181 °C), mechanical properties (tensile strength = 85 MPa, elongation at break = 13.5 %), and dielectric properties (D k = 2.526 and D f = 0.113 at 15 GHz). These formulations meet the performance requirements for circuit board substrates and lead the industry in mechanical and dielectric properties. Furthermore, the feasibility of inkjet printing heterogeneous integrated electronic devices was verified, showing excellent print resolution and continuity of the conductive network. This work provides new insights into the future development of dielectric materials for inkjet 3D printing.
研究领域:
材料科学
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电子工程
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化学工程
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高影响因子
REACTIVE & FUNCTIONAL POLYMERS
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2018
·
IF 2.975
Abdul Qadeer Dayo,An-ran Wang,Mehdi Derradji,Sadia Kiran,Abdeldjalil Zegaoui,Jun Wang,Wen-bin Liu
The eugenol based phthalonitrile (EPN) monomer was successfully copolymerized with mono and difunctional benzoxazine (P-a and BA-a) monomers via concerted catalysis polymerization . The loading of EPN in benzoxazine monomers was varied from 10 to 40 wt% and impacts of loading on thermal, thermomechanical and mechanical properties were studied. The FTIR analysis confirmed that both poly(P-a/EPN) and poly(BA-a/EPN) copolymers can be completely cured without the addition of curing additive. The addition of the bio-based EPN monomer enhanced the curing peak temperatures and reduced the curing reaction enthalpies . Initially, OH groups were produced from the oxazine ring opening polymerization of benzoxazine and they enhanced the curing of EPN. The thermal stabilities, as well as the stiffness and T g of the copolymers, were much higher as compared to the neat polymers. Highest values were seen on the 40 wt% loading of EPN monomer in the copolymers. Moreover, the difunctional benzoxazine based copolymer showed higher enhancements in the properties as compared to the mono-functional benzoxazine based copolymer. The decline was seen in the flexural properties as EPN monomer contains the flexible chain in the structure. The morphological changes supported all the claims for the copolymers. The prepared copolymers can be used as a high performance thermosetting resin .
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2016
·Vol. 97
·期 8
·2426-2435
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IF 2.076
Li Li,Liru Xia,Yongfu Zhao,Min Wang,Xizhi Jiang
BACKGROUND Mycotoxins are produced by fungi as secondary metabolites. They often multi-contaminate food and feed commodities posing a health risk to humans and animals. Fast and easy multiplex screening could be thought as a useful tool for detection of multi-contaminated food and feed commodities. RESULTS A highly sensitive immune-affinity monolithic arrays for detecting the mycotoxins zearalenone, deoxynivalenol, T-2 toxin, HT-2 toxin, aflatoxins, ochratoxin A, and fumonisin B 1 were fabricated using UV induced co-polymerisation. The mycotoxin antibodies firstly reacted with functional monomer to form antibody/functional monomer bio-conjugates. Subsequently, the antibody/functional monomer bio-conjugates co-polymerised with cross-linker to form mycotoxins immune-affinity arrays. With optimal fabrication conditions, all mycotoxin immune-affinity monolithic arrays exhibited a linear response spanning three orders of magnitude. And the immune-affinity monolithic array has a low detection limit and has a good uniformity (intra-assay CV, and inter-assay CV both <8%). CONCLUSION The fabricated mycotoxin immune-affinity monolithic arrays were proved as a sensitive, stable and economical tool in real food samples detection. Moreover, the mycotoxin immune-affinity monolithic arrays would be able to minimise manipulation steps: add samples and enzyme labelled mycotoxins, and detect CL signals. © 2016 Society of Chemical Industry
研究领域:
食品科学
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分析化学
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免疫学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2017
·
IF 3.981
Chusheng Liu,Haibin Li,Qiqin Wang,Jacques Crommen,Haibo Zhou,Zhengjin Jiang
The quest for higher column efficiency is one of the major research areas in polymer-based monolithic column fabrication. In this research, two novel polymer-based HILIC monolithic columns with 400 μm I.D. × 800 μm O.D. were prepared based on the thermally initiated co-polymerization of N,N -dimethyl- N -(3-methacrylamidopropyl)- N -(3-sulfopropyl) ammonium betaine (SPP) and ethylene glycol dimethacrylate (EDMA) or N,N’ -methylenebisacrylamide (MBA). In order to obtain a satisfactory performance in terms of column permeability, mechanical stability, efficiency and selectivity, the polymerization parameters were systematically optimized. Column efficiencies as high as 142, 000 plates/m and 120, 000 plates/m were observed for the analysis of neutral compounds at 0.6 mm/s on the poly(SPP- co -MBA) and poly(SPP- co -EDMA) monoliths, respectively. Furthermore, the Van Deemter plots for thiourea on the two monoliths were compared with that on a commercial silica based ZIC-HILIC column (3.5 μm, 200 Å, 150 mm × 300 μm I.D.) using ACN/H 2 O (90/10, v/v) as the mobile phase at room temperature. It was noticeable that the Van Deemter curves for both monoliths, particularly the poly(SPP- co -MBA) monolith, are significantly flatter than that obtained for the ZIC-HILIC column, which indicates that in spite of their larger internal diameters, they yield better overall efficiency, with less peak dispersion, across a much wider range of usable linear velocities. A clearly better separation performance was also observed for nucleobases, nucleosides, nucleotides and small peptides on the poly(SPP- co -MBA) monolith compared to the ZIC-HILIC column. It is particularly worth mentioning that these 400 μm I.D. polymer-based HILIC monolithic columns exhibit enhanced mechanical strength owing to the thicker capillary wall of the fused-silica capillaries.
研究领域:
分析化学
·
色谱技术
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产品关联
DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
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2024
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IF 7.2
Xinxu Zhao,Chaoqun You,Xun Li,Yu Zhang,Fei Wang
The limited solubility of lignin in commonly used solvents poses a challenge for its depolymerization into high-value monomers. This paper investigates the solubility of alkali lignin in water, methanol, ethanol, acetone, 1,4-dioxane, and their binary solution, and examines their impact on lignin depolymerization. The distribution of depolymerization products was correlated with the chemical structure changes in various solvent. Among the solvents tested, water-acetone mixtures demonstrated exceptional solubility for alkali lignin (95.24%) and provide the highest yield of bio-oil and phenolic monomers. The enhanced solubility of guaiacol units in acetone, combined with the addition of water in the co-solvent system dramatically improved the solubility of alkali lignin. Moreover, formic acid donated hydrogen protons to facilitate lignin depolymerization and prevented the repolymerization of unstable intermediates. Optimal reaction conditions were achieved at 300 °C for 120 mins using a mixed solvent composed of water, acetone, and formic acid in a ratio of 5:5:1 ( v /v/v), corresponding to the highest yield of bio-oil with 81.45 wt%, the lowest yield of residue with 6.20 wt%, and a phenolic monomer content of 57.48%. Furthermore, this co-solvent system revealed satisfactory adaptability for converting various lignin into phenolic monomers.
研究领域:
化学工程
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生物质能
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）