Journal of Macromolecular Science Part A-Pure and Applied Chemistry
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2024
·
IF 2.1
Lifen Xiao,Hongwei Peng,Xiaoming Zhu,Yang Huang,Geng Huang,Wei Li
Endo-norbornene derivatives are much cheaper and more accessible. However, it is difficult to prepare endo-polynorbornenes with ultra-high molecular weight (UHMW) by ring opening metathesis polymerization (ROMP) owing to the low activity. The molecular weight of poly(endo-NB-2OH)n could only reach to 309.1 kg mol−1 for 24 h via ROMP. While, UHMW poly(endo-NB-2OH)m was prepared by combining ROMP and acyclic metathesis reaction in much shorter time. The effects of residual monomer, amount of H2SO4, concentration, temperature and reaction time were investigated in depth. The UHMW P(endo-NB-2OH)m (Mn=2645.5 kg mol−1, PDI = 1.74) could be obtained at 80 °C for 5 min with H2SO4/G3 as 10/1 and concentration of 0.1 M. Moreover, UHMW P(endo-NBI-OH)m(Mn=1114.2 kg mol−1, PDI = 1.95) was also successfully prepared by this method. However, the H2SO4/G3 should increase to 30/1, and reacted for 45 min owing to the steric resistance of the cyclic dicarboximide. For P(exo-NBI-OH)n with lower activity, reaction time should prolong to 3 h to obtain UHMW P(exo-NBI-OH)m(Mn=1716.7 kg mol−1, PDI = 1.93). Finally, UHMW P(endo-NB-2alkyne)m, P(endo-NBI-alkyne)m, and P(exo-NBI-alkyne)m were successfully prepared via post-modification. Acyclic metathesis reaction is a robust and universal reaction to prepare other functional UHMW polynorbornenes, especially for the UHMW endo-polynorbornenes, which could not be prepared by ROMP efficiently.
研究领域:
高分子化学
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有机合成
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功能高分子
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材料科学
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聚合物化学
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DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
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2011
·Vol. 212
·期 21
·2378-2388
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IF 2.437
Bin Yuan,Xiaohui He,Yiwang Chen,Kaiti Wang
Covalently immobilized silica-supported acetylacetonate dichloride palladium(II) precatalyst is prepared by the reaction of silica particles grafted acetylacetonate ligand further exchange with [Et 4 N] 2 PdCl 4 . The silica-supported catalyst is used in slurry polymerizations of norbornene (NB) to afford a highly productive NB addition polymerization system in combination with B(C 6 F 5 ) 3 cocatalyst. It exhibits productivity of 84 kg of PNB (mol Pd) −1 h −1 at the initial activity, and the catalyst deactivation kinetics in the early stage of polymerization are fitted well by the first-order deactivation kinetics. The obtained vinyl-type polynorbornene is confirmed to be nanosilica hybrid PNB nanocomposite by SEM, TEM with an energy dispersive spectrometer, TGA, and XRD.
研究领域:
高分子化学
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纳米复合材料
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催化化学
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有机金属化学
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材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 63
·36298-36312
·
IF 2.936
Xiaohui He,Guangshui Tu,Feng Zhang,Shengmei Huang,Changwen Cheng,Chuanyi Zhu,Yapeng Duan,Suli Wang,Defu Chen
Eight bis-(salicylaldehyde-benzhydrylimino)nickel complexes with different electron groups (Ni1–Ni8), Ni{(3-R1)(5-R2)C6H2(O)CHNCH(C6H5)2}2, (R1 = H, R2 = H, Ni1; R1 = H, R2 = CH3, Ni2; R1 = H, R2 = OCH3, Ni3; R1 = H, R2 = Br, Ni4; R1 = CH3, R2 = H, Ni5; R1 = OCH3, R2 = H, Ni6; R1 = Br, R2 = Br, Ni7; R1 = Cl, R2 = Cl, Ni8), were synthesized and their crystal structures were characterized using single crystal X-ray diffraction. The results revealed that Ni1–Ni6 belong to the monoclinic system (space group P2(1)/n), Ni7 belongs to the monoclinic system (space group C2/c) and Ni8 belongs to the triclinic system (space group P). All nickel complexes exhibited high activities (0.46–2.07 × 106 gpolymer molNi−1 h−1) toward norbornene homopolymerization, and a strong electron-withdrawing group on the salicylaldimino aromatic ring can enhance the catalytic activity and favor polymerization. Ni1 and Ni2 exhibited high activities (0.55–2.40 × 105 gpolymer molNi−1 h−1) toward copolymerization of norbornene and 1-hexene in the presence of B(C6F5)3. The 1-hexene content in the copolymers could be controlled up to 7.98–12.50% by varying the comonomer feed ratio of 1-hexene from 10 to 50%. It is observed that when the 5-position of the salicylaldimino aromatic ring has a substituent (–CH3), the 1-hexene insertion rate is lower than that without a substituent. In addition, the polymers showed high molecular weights (1.5–2.4 × 105 g mol−1) and narrow molecular weight distributions (1.62–1.89). The obtained polymers were also verified to be amorphous copolymers and had high thermal stability, good solubility and optical transparency.
研究领域:
化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 9
·3944
·
IF 4.6
Yin Lu,Yaliang Peng,Yi Yang,Jiahao Liu,Kan Zhang
There is an urgency to produce novel high-performance resins to support the rapid development of the aerospace field and the electronic industry. In the present work, we designed and consequently synthesized a benzoxazine monomer (oHPNI-fa) bearing both norbornene and furan groups through the flexible benzoxazine structural design capability. The molecular structure ofoHPNI-fawas verified by the combination characterization of nuclear magnetic resonance spectrum, FT-IR technology, and high-resolution mass spectrum. The thermally activated terpolymerization was monitored by in situ FT-IR as well as differential scanning calorimetry (DSC). Moreover, the low-temperature-curing characteristics ofoHPNI-fahave also been revealed and discussed in the current study. Furthermore, the curing kinetics of theoHPNI-fawere investigated by the Kissinger and Ozawa methods. The resulting highly cross-linked thermoset based onoHPNI-fashowed excellent thermal stability as well as flame retardancy (Td10of 425 °C, THR of 4.9 KJg−1). The strategy for molecular design utilized in the current work gives a guide to the development of high-performance resins which can potentially be applied in the aerospace and electronics industries.Keywords:benzoxazine;norbornene;furan;thermosets;thermal stability
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
PubMed
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 22
·8791-8796
·
IF 8.067
Jie Liu,Si-Yu Gao,Xin-Yi Zhang,Yakai Feng,Han-Chun Wu,Zhijian Chen,Maxim V. Bermeshev,Xiang-Kui Ren
POSS-containing polynorbornene with pendant perylene diimide (PPDI-POSS) has been synthesized, with alkyl-containing polynorbornene (PPDI-C10C8) as the reference. The supermolecular structure and photoluminescence properties were elucidated using UV-Vis absorption spectra, and one- and two-dimensional X-ray diffraction. The experimental results reveal that PPDI-C10C8 possesses a lamellar structure with close PDI stacking to meet the requirement for minimum free energy. However, the introduction of POSS cages endows PPDI-POSS with a unique hexagonal columnar structure and enhanced photoluminescence properties due to the steric hindrance of POSS cages. These results may contribute to the understanding of the structure–property relationship of the optical polymers and provide some useful information for the design of polymer materials with a controllable supramolecular structure and tunable luminescence properties.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
Marine Drugs
·
2017
·Vol. 15
·期 7
·223
·
IF 3.503
Na Li,Huanhuan Wang,Xiaosai Qu,Yu Chen
ROMP is an effective method for preparing functional polymers due to its having characteristics of “living” polymerization and rapid development of catalysts. In the present work, poly(norbornene-methylamine), a mimic of chitosan, was synthesized via ROMP reaction. The amino-protected product, 5-norbornene-2-(N-methyl)-phthalimide, was prepared by a reaction of 5-norbornene-2-methylamine with phthalic anhydride, which was then subjected to the ROMP reaction in the presence of Hoveyda-Grubbs 2nd catalyst to afford poly(norbornene-(N-methyl)-phthalimide). The target product, poly(norbornene-methylamine), was obtained by deprotection reaction of poly(norbornene-(N-methyl)-phthalimide). The products in each step were characterized by FTIR and1H-NMR, and their thermal stabilities were determined by TG analysis. The effects of molar ratio between monomer ([M]/[I]) and catalyst on the average relative molecular weight (Mn¯) and molecular weight distribution of the produced polymer products were determined by gel permeation chromatography (GPC). It was found that theMn¯of poly(norbornene-(N-methyl)-phthalimide) was controllable and exhibited a narrow polydispersity index (PDI) (~1.10). The synthesis condition of 5-norbornene-2-(N-methyl)-phthalimide was optimized by determining the yields at different reaction temperatures and reaction times. The highest yield was obtained at a reaction temperature of 130 °C and a reaction time of 20 min. Our work provides a new strategy to synthesize polymers with controllable structures and free –NH2groups via ROMP.Keywords:ROMP;poly(norbornene-methylamine);controllable;living polymerization;chitosan
研究领域:
高分子化学
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生物材料科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2016
·Vol. 54
·期 23
·3733-3740
·
IF 3.114
Jing Xu,Hongwei Zhang,Luoxin Wang,Meng Chen,Dan Luo
We demonstrate that polynorbornene containing primary activated bromide moieties is a novel chemically modifiable platform for postpolymerization modification. Polymer P0 was synthesized via ring-opening metathesis polymerization of monomer 1 with the assistance of Grubbs third generation (G-III) catalyst. Subsequently, nucleophilic substitution was conducted by mixing P0 with n -caproic acid, sorbic acid, m -toluic acid or 4-nitrobenzoic acid in the presence of 1,1,3,3-tetramethylguanidine (TMG) under mild and stoichiometric condition to generate functionalized polymers P1–P4 . NMR results approved full conversion of the reactive sites and exemplified the “click” nature of TMG promoted esterification. Thermal stability and glass transition behaviors of all the polymer samples were investigated by thermal gravimetric analysis and differential scanning calorimetry. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54 , 3733–3740
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2012
·Vol. 1
·期 7
·1482-1490
·
IF 0
Hong Yang,Fei Zhang,Bao-Ping Lin,Patrick Keller,Xue-Qin Zhang,Ying Sun,Ling-Xiang Guo
This manuscript describes a series of mesogen-jacketed liquid crystalline polymers (MJLCPs) and elastomers (MJLCEs) bearing a novel polynorbornene backbone, onto which the liquid crystalline mesogen is laterally attached by a single covalent bond without spacers. The side-on mesogenic monomers are synthesized via palladium-catalyzed exo-hydroarylation of norbornadiene, and then polymerized using a Grubbs' catalyst initiated ring opening metathesis polymerization (ROMP) method. MJLCEs are prepared by mixing the MJLCPs with bifunctional benzophenone cross-linkers, pulling fibers to achieve a fine alignment, and crosslinking under UV illumination. Their mesomorphic, thermo-actuation and mechanical properties are studied in detail by a combination of 1H NMR, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, polarized optical microscopy, X-ray diffraction and dynamic mechanical analysis. These newly designed polymers can decouple the dynamics of the very bulky and rigid polynorbornene main chain and the mesogenic side groups to achieve liquid crystallinity, only if the length of alkoxy terminal chains of the mesogens is long enough (the number of the carbons in the alkoxy group, n > 9). Moreover, interesting external force induced reversible thermal-actuation behaviors of smectic MJLCEs are observed and analyzed as well.
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
INORGANIC CHEMISTRY COMMUNICATIONS
·
2020
·
IF 1.943
Haibin Yuan,Hui Liu,Fen You,Xiaochao Shi
Palladium complexes bearing new tridentate quinolino-based [N − NN ox ] ligands were synthesized and tested for the polymerization of norbornene. Upon activation of MAO, all the palladium complexes showed high catalytic activities for the vinyl-addition polymerization of norbornene up to 11.5 × 10 6 g of PNB (mol of Pd) −1 h −1 . The structure–activity relationships in the polymerization of norbornene, namely steric and electric effects of the ligands, were carefully investigated.
研究领域:
有机化学
·
高分子化学
✓ 已验证
DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Xiong Xiao,Ziwei Huang,Xia Jiang,Yuchu Yang,Liping Yang,Shaojie Yang,Chuan Niu,Yue Xu,Li Feng
Norbornene modified hyaluronic acid (NorHA) has attracted enormous attention in biological research for its ability to form hydrogels in a cell-friendly way. However, traditional routes to synthesis NorHA are involved with laboring and cumbersome steps. In this study, an alternative single-step approach to fabricate NorHA is reported. NorHA was first synthesized by conjugating carbic anhydride (CA) with hyaluronic acid (HA) directly and NorHA with various norbornene substitution degrees (SD) was obtained by adjusting the reaction pH, time, and the amounts of CA easily. Porous NorHA hydrogels were prepared via orthogonal thiol-norbornene reaction under blue light irradiation . Furthermore, the resulting gelation performances, swelling behaviors, and transmittance of NorHA hydrogels were adjusted by varying the content of crosslinker or NorHA. The cytocompatibility evaluation suggests that the obtained NorHA were suitable for cell encapsulation. Finally, we show that this approach also can be extended to other natural or synthesized biopolymers to prepare cytocompatible photo-crosslinked hydrogels.
研究领域:
生物材料
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生物医学工程
·
高分子化学
·
组织工程
✓ 已验证
产品关联
DOI
高影响因子
MRS Communications
·
2020
·Vol. 10
·期 3
·487-491
·
IF 1.997
Zhenghui Li,Lu Chen,Peijie Yu,Lingli Zhang,Hongyu Hu
To overcome the steric effect of norbornene (NB), first-generation Grubbs’ catalyst (GC1) was used as the catalyst to graft NB onto the polypropylene (PP) chain by reactive extrusion. Instead of harsh reaction conditions, such as anhydrous, which was the general method to synthesize NB polymers, this convenient method would be easier to industrialize. The mechanism of grafting was studied by using Fourier Transform InfraRed spectra and differential scanning calorimetry. It was found that GC1 could initiate the ring-opening metathesis polymerization of NB to obtain short NB chain-grafted PP-g-NB. The rheological behavior showed that the grafted NB short chains on PP-g-NB increase the shear thinning of the polymers and decrease the system viscosity.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
Fuel Cells
·
2013
·Vol. 14
·期 1
·26-34
·
IF 2.364
X.-H. He,Y. Zheng,H.-L. Yao,Y.-W. Chen,D.-F. Chen
A series of novel hybrid sulfonated polynorbornene-silica (PBN–SiO 2 ) proton conducting membranes doped with different weight ratio of phosphotungstic acid (PWA) were prepared by the casting procedure. The proton conductivity of the composite membranes containing 40 wt.% PWA reached the maximum of 6.1 × 10 –2 S cm –1 and increased gradually with PWA content and temperature elevating, while the methanol permeabilities (3.52–9.39 × 10 –7 cm 2 s –1 ) of these membranes were much lower than that of Nafion 117 (2.36 × 10 –6 cm 2 s –1 ). The membranes also exhibited excellent thermally stable and mechanical properties, which imply that the PBN–SiO 2 –PWA membranes are promising materials in the direct methanol fuel cells (DMFC) applications.
研究领域:
材料科学
·
能源工程
✓ 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）