POLYMERS FOR ADVANCED TECHNOLOGIES
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2017
·Vol. 28
·期 11
·1438-1447
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IF 1.907
Xin Liu,Xuewen Guo,Yunfei Zhi,Shaoyun Shan,Yonghao Ni,Qingming Jia
The recent development of sulfur dioxide (SO 2 ) polymerization has seen a renaissance in its chemistry, especially poly(olefin sulfone)s from the copolymerization of SO 2 , and unsaturated hydrocarbons can be found to have many applications, including transient electronic packaging, drug delivery, and electron beam-resistant materials. In this work, a type of functional poly(norbornene sulfone) was synthesized via two different polymerization methods. Aiming to understanding the effects of different polymerization methods on poly(olefin sulfone)s and gain further understanding on the kinetics of poly(olefin sulfone)s's thermal instability, we investigated their detailed thermal degradation behaviors using thermogravimetry and analyzed the resultant kinetics in accordance with three kinetic models. The results supported the conclusion that although the poly(norbornene sulfone)s obtained have different activation energy, the thermal degradation kinetics are the same and also obey the D n type. Copyright © 2017 John Wiley & Sons, Ltd.
研究领域:
高分子化学
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材料科学
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热分析
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功能高分子
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可控降解材料
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DOI
高影响因子
ACS Applied Polymer Materials
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2019
·
IF 0
Kan Zhang,Xinye Yu,Yuting Wang,Yuqi Liu
Phthalonitrile polymers exhibit many attractive advantages including high thermal and mechanical properties, low water absorptivity, and excellent flame retardancy. However, the poor processability requiring high temperature polymerization for long duration seriously impedes their further applications. In this work, a benzoxazine monomer bearing both norbornene and phthalonitrile functionalities (oHPNI-apn) has been synthesized, and its chemical structure has been confirmed by NMR, FT-IR, and elemental analysis. In addition, the polymerization behavior of oHPNI-apn has been systematically studied using DSC, in situ FT-IR and solid-state 13C NMR analysis. The phthalonitrile in this developed thermosetting system can be thermally induced polymerized at a relatively lower temperature with no added catalysts, which indicates the existence of self-catalyzed effect during the terpolymerization of oHPNI-apn. Moreover, oHPNI-apn-based thermoset is found to possess excellent thermal stability and outstanding flame retardancy, with extremely high Tg temperature (419 °C), very high char yield value (68%, at 800 °C in N2), and extraordinarily low heat release capacity (25.1 J/(g K)) in the absence of any added antiflammable additives.
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
POLYMER DEGRADATION AND STABILITY
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2017
·
IF 3.386
Xue Dong,Rong-Tao Duan,Yan-Peng Ni,Zhi-Jie Cao,Li Chen,Yu-Zhong Wang
Retro-Diels-Alder reaction (rDA) has been widely used as a common modification approach for expanding functional applications of polymers. Especially, it has become an effective method of current cross-linking chemistry . With the goal of designing a cross-linkable PET-based copolyester toward flame retardancy and anti-dripping during combustion, dimethyl 5-(1,3-dioxo-3a,4,7,7a-tetrahydro-1 H -4,7-methanoisoindol-2(3 H )-yl) isophthalate (DMTMI) was incorporated as the functional co-monomer into PET chains via random transesterification polycondensation . Thermogravimetry-differential scanning calorimetry (TG-DSC) and rheological studies demonstrated the existence of cross-linking behavior at high temperature. By controlling the co-monomer content, expected flame retardancy was obtained, as illustrated by the results from the limiting oxygen index (LOI) and cone calorimetry. Furthermore, LOI values increased firstly and then decreased with the content of DMTMI increased, which was related to the existence of rDA reaction, and further proposed that a competitive relationship between the release of inflammable cyclopentadiene during rDA reaction and cross-linking behavior occurred in combustion. The hypothesis was verified through pyrolysis-gas chromatograph-mass spectrometry (Py-GC-MS).
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
POLYMER INTERNATIONAL
·
2017
·Vol. 66
·期 11
·1530-1537
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IF 2.07
Xuewen Guo,Xin Liu,Hongying Su,Shaoyun Shan,Qingming Jia
Photoresists involving polymer solubility and degradation play a crucial role in the manufacture of integrated circuits by photolithography. Conventional photoresists typically rely on a single switching mechanism based on a change in either polarity or molecular weight of the polymer. Here we report a new type of poly(olefin sulfone) as a photoresist which overcomes the drawback of poor dry etching resistance, solubility and thermal degradation. The effects of different side-chain groups (acetyl, acetoxy and carboxylic acid) of norbornene on the properties of poly(norbornene sulfone)s were analyzed with the aim of developing a new type of photoresist. Thermogravimetry and gel permeation chromatography results revealed that bond breaking occurred at different temperatures, because of the different side-chain groups, and the three side-chain groups affect the solubility and stability of the poly(norbornene sulfone)s. A novel photoresist material based on a poly(olefin sulfone) with different side-chain groups was synthesized and its physical properties examined. © 2017 Society of Chemical Industry
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Xianzhe Sheng,Shuhuan Yun,Xing Miao,Zhenyu Xiong,Weiran Tang,Xuetao Shi,Jianbin Qin,Zhonglei Ma,Yongsheng Zhao,Guangcheng Zhang
High-performance polyimide foams combining exceptional heat resistance with robust mechanical properties are increasingly in demand in lightweight applications requiring thermal stability, insulation, and flame retardancy. Herein, we present a scalable fabrication strategy for thermally stable and compression strength robust co-cross-linked acetylene-terminated polyimide rigid foams (PIRFs) through the foaming of acetylene-end-capped precursor powders using a norbornene-terminated cross-linking blowing agent (NE-CBA). A series of acetylene-terminated polyimide oligomers (AE-PIO) with controlled molecular weights were synthesized and subsequently melt-copolymerized with an m-phenylenediamine-derived cross-linking blowing agent (NE-CBA-MPD) to establish high-density co-cross-linked networks. The polyimide rigid foams (PIRFs) synthesized from acetylene-terminated precursor powders (Mn = 2264 g/mol) demonstrate exceptional multifunctional characteristics. Specifically, these materials exhibit remarkable thermal stability evidenced by a glass transition temperature (Tg) of 415.1 °C and 10% weight loss temperature (T10%) at 572.0 °C. The mechanical performance remains robust across temperature regimes, with compressive strengths of 2.72 MPa at ambient conditions and 2.58 MPa under thermal stress at 200 °C, achieved at a low density of 140 kg/m3. Furthermore, the foams display superior insulation capabilities, maintaining ultralow thermal conductivity values (λ < 0.035 W/m·K) throughout the 25–200 °C range. Notably, the material achieves Class A fire resistance standards with a limiting oxygen index (LOI) exceeding 45%, demonstrating exceptional flame retardancy. These co-cross-linked PIRFs achieved an optimal balance between structural integrity and foam expansion, showing significant potential as advanced structural materials for extreme environments in aerospace engineering, naval architecture, rail transportation, and other specialized high-temperature applications.
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
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Hao Li,Xue Liu,Yang Xiao,Kun Cao
5-Norbornene- exo -2,3-dicarboxylic anhydride ( exo -NDA), widely used in the synthesis of medicine and pesticide, was primarily obtained through the subsequent thermal isomerization of 5-norbornene- endo -2,3-dicarboxylic anhydride ( endo -NDA) synthesized from cyclopentadiene (CPD) and maleic anhydride (MAH). Herein, density functional theory (DFT) was employed to elucidate the transition states and reaction pathways of different configurations. The endo -path exhibited a lower energy barrier, and the exo -isomer demonstrates greater structural stability. It was found that both high temperature and solvent polarity influenced the generation of NDA with different configurations. Due to considering solubility of MAH, an acetone/ethylbenzene mixed solvent was chosen for the reaction instead. According to the DFT calculations, we developed continuous-flow microreactor for high-efficiency one-pot synthesis of the isomers with exo / endo ratio of up to 1.19:1 as well as almost 100 % conversion and 98 % selectivity just in 2 min at 260 °C and 4 MPa, which CPD was generated in situ to participate in a series of Diels-Alder reactions instead of dicyclopentadiene as raw material existed at room temperature. Moreover, excessive or insufficient pressure in the reaction system should elevate byproduct formation, resulting in a decrease in reaction selectivity, as could prolonged residence time.
研究领域:
化学工程
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有机化学
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催化
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计算化学
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产品关联
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
JOURNAL OF CHEMICAL THERMODYNAMICS
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2019
·
IF 2.29
Yameng Wan,Pengshuai Zhang,Haixia He,Jiao Sha,Rui Zhao,Tao Li,Baozeng Ren
Solubility of cis-5-norbornene-exo-2,3-dicarboxylic anhydride (himic anhydride) in thirteen solvents including methyl acetate (MAC), ethyl acetate (EAC), n -propyl acetate (NPAC), isopropyl acetate (IPAC), n -butyl acetate (NBAC), isobutyl acetate (IBAC), n -amyl acetate (NAAC), methanol (MtOH), ethanol (EtOH), acetone (DMK), N-methyl-2-pyrrolidinone (NMP), N,N-dimethylformamide (DMF) from 278.15 K to 323.15 K and 1,4-dioxane at (288.15–323.15) K was experimentally determined by the gravimetric method under 0.1 MPa. The results showed that the solubility of himic anhydride increased with increasing temperature. The interaction energy between himic anhydride and selected solvents was calculated by molecular simulation to reveal the solubility behavior. Solubility data was correlated by five activity coefficient models including the Two-Suffix Margules model, Wilson model, NRTL model, NRTL-SAC model and uniquac model. Values of ARD (average relative deviations) and RMSD (root-mean-square deviation) between experimental and calculated solubility showed that five activity coefficient models provided good performance in this work. Moreover, thermodynamic properties associated with the solution processes were also discussed.
研究领域:
物理化学
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材料科学
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2024
·Vol. 15
·期 21
·2148-2156
·
IF 4.1
Xiao-Yu Zhang,Hao-Liang Li,Bo Xiang,Xiang-Wei Liu,Shu Zhang,Yi-Xian Wu
A series of imidazolidin-2-iminato vanadium complexes VOCl2[1,3-R2-(CH2N)2CN], Vi1, R = 2,6-Me2C6H3; Vi2, 2,4,6-Me3C6H2; Vi3, R = 2,6-iPr2C6H3; Vi4, R = cyclohexanyl, were synthesized and fully characterized by NMR (1H, 13C and 51V) and elemental analysis. The copolymerizations of ethylene with propylene using the imidazolidin-2-iminato vanadium complexes were conducted in the presence of Et3Al2Cl3. The catalytic activity increased in the order of Vi4 < Vi1 < Vi2 < Vi3, probably due to the different electron donating natures of the imidazolidin-2-iminato ligands. Both high catalytic activity of 2.44 × 106 g copolymer per mol of V per h and incorporation ratio of propylene (up to 32.5 mol%) were afforded by using the Vi3/Et3Al2Cl3 catalytic system in the copolymerization of ethylene with propylene. An ethylene–propylene copolymer with ultra-high molecular weight (Mw = 2660 kg mol−1) could be also synthesized by using the Vi3/Et3Al2Cl3 catalytic system. Importantly, the highly efficient terpolymerizations of ethylene, propylene with 5-ethylidene-2-norbornene (ENB) were also achieved by using this catalytic system, affording ethylene–propylene–ENB terpolymers (EPDMs) with high contents of ENB units up to 9.8 mol% (29.8 wt%) and ultra-high molecular weight (Mw = 1521–2537 kg mol−1). This work offers a unique catalytic system of vanadium complexes for the synthesis of EPDM with both high content of ENB units and ultra-high molecular weight.
研究领域:
聚合物化学
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材料科学
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2019
·
IF 4.561
Yameng Wan,Haixia He,Pengshuai Zhang,Zibo Huang,Rui Zhao,Jiao Sha,Tao Li,Baozeng Ren
Solubility of cis-5-norbornene-endo-2,3-dicarboxylic anhydride (carbic anhydride) in fourteen pure solvents including methyl acetate (MAC), ethyl acetate (EAC), n-propyl acetate (NPAC), isopropyl acetate (IPAC), n-butyl acetate (NBAC), n-amyl acetate (NAAC), isoamyl acetate (IAAC), hexyl acetate (HAC), octyl acetate (OAC), ethanol (EtOH), 1,4-dioxane, 1-methyl-2-pyrrolidinone (NMP), acetone, N , N -dimethylformamide (DMF) and three binary solvents of (DMF + EtOH), (1,4-dioxane + EtOH) and (EtAC + EtOH) with various mass fractions was experimentally studied at various temperatures under 0.1 MPa. The results showed that solubility of carbic anhydride increased with the increasing temperature in all pure/binary solvents and decreased with the increasing mass fractions of ethanol in binary solvents. The Hansen solubility parameter was used for explaining the solubility order of carbic anhydride in selected solvents. Solubility of carbic anhydride in pure solvents was correlated by van't Hoff equation, modified Apelblat equation, and λh equation. Experimental solubility of carbic anhydride in binary solvents was correlated by Jouyban-Acree model, Jouyban-Acree-modified Apelblat model, Jouyban-Acree-van't Hoff model, Sun model and Ma model. Moreover, thermodynamic properties of solutions were calculated by the van't Hoff analysis. The dissolution process was always endothermal and entropy-driven.
研究领域:
化学工程
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物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Yameng Wan,Haixia He,Zibo Huang,Pengshuai Zhang,Jiao Sha,Tao Li,Baozeng Ren
In this work, solubility of 5-norbornene-2,3-dicarboximide (NODI) in three binary solvents (DMF + methanol, ethanol, ethyl acetate) was experimentally investigated by using laser monitoring technique at (278.15 to 323.15) K under 0.1 MPa. Solubility data of NODI increased as the temperature increased while reduced with the decreasing mass fraction of DMF. Hansen solubility parameter was employed to reveal the solubility behavior of NODI. Experimental solubility data was correlated by five thermodynamic models including NRTL, Wilson, uniquac, Margules and Jouyban-Acree-modified Apelblat (J-A-A) model. The Wilson, Margules, and uniquac model were more suitable to correlate NODI solubility than others. Besides, thermodynamic properties of mixing process (Δ mix G , Δ mix S , Δ mix H , H 1 E , ∞ , ln γ 1 and ln γ 1 ∞ ) were investigated based on solubility data and the Wilson equation. Mixing processes of NODI in three binary solvents were entropy-driven.
研究领域:
化学工程
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物理化学
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热力学
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Yameng Wan,Haixia He,Pengshuai Zhang,Rui Zhao,Jiao Sha,Tao Li,Baozeng Ren
In this work, solubility of cis-5-norbornene-exo-2,3-dicarboxylic anhydride (himic anhydride) in binary solvents of (1,4-dioxane, DMF, NMP + ethanol) was experimentally determined by the gravimetric method ranged from 278.15 K to 323.15 K under 0.1 MPa. It was found that solubility of himic anhydride increased with elevating temperature while decreased as the mass fraction of ethanol increased. Solubility order of himic anhydride in three binary solvents was interpreted by comparing the interaction energy ( E inter ) between solute and binary solvents based on density function theory (DFT). Experimental solubility in binary solvents was correlated by the Two-Suffix Margules, NRTL, Wilson, uniquac and Jouyban-Acree-modified Apelblat (J-A-A) model. The Wilson, NRTL, uniquac and Two-Suffix Margules model are suitable to correlate the experimental solubility. Moreover, thermodynamic properties of dissolution process (Δ dis G , Δ dis S , Δ dis H , Δ mix G , Δ mix S , Δ mix H , H 1 E , ∞ , ln γ 1 and ln γ 1 ∞ ) were calculated by the Wilson equation. The dissolution process and mixing process of himic anhydride in selected binary solvents are entropy-positive.
研究领域:
化学工程
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物理化学
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热力学
✓ 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）