JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2024
·
IF 4.7
Wang Guoqiang,Hui Yunfeng,Wei Deyu,Wang Yueying,Yu Yiheng,Shi Longqing,Zhang Mengke,Hu Jing
Poly(butylene succinate) (PBS), a biodegradable material, has excellent mechanical properties and processing properties. Brassylic acid (BA) is a kind of diacid with long chains derived from biomass. In this study, poly(butylene succinate-co-butylene brassylate) is synthesized to investigate the effects of BA on the structure and properties of PBS. The relationship between the melting temperature of copolyesters and the content of butylene brassylate units is V-shaped, which is typical of isodimorphic random copolyesters. Due to the introduction of BA, the density of unstable ester bonds in copolyesters gradually decreases and the initial thermal decomposition temperature of copolyesters gradually increases with the increase of BA. The dynamic mechanical analysis showed that the glass transition temperature of PBS was reduced by the introduction of BA. When the BA content is 25%, the copolyesters and PBS have the same crystal structure. When the BA content is 50–100%, the copolyesters and poly(butylene brassylate) have the same crystal structure, which indicates that the butylene brassylate units are easier to crystallize than the butylene succinate units. The ductility of copolyesters increases with the addition of BA. When the BA content is 50%, the elongation at break reaches the maximum (> 2000%). The copolyesters are suited for films due to high elongation at break.
研究领域:
材料科学
·
生物化学
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DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2022
·Vol. 33
·期 8
·2542-2551
·
IF 3.348
Li Fan,Ke Cao,Huan Hu,Jiajun Ma,Qiuxia Peng,Xian Li,Yawen Huang,Junxiao Yang
UV-curable resins with low dielectric constant can be processed or patterned to form required shapes, making them highly applicable to special fields. In our previous study, UV-curable siloxane-benzocyclobutene resins were synthesized, but their dielectric constants were relatively high. In this work, silylbutylene-benzocyclobutene oligomers (ADM-PBSC) were synthesized by acyclic diene metathesis (ADMET) polymerization of 1,1-dibutenylsilacyclobutane monomers with benzocyclobutene terminated groups. In this way, siloxane moieties were replaced by silylbutylene groups to further reduce dielectric constant while preserving UV curable properties. The UV/thermally cured ADM-PBSC exhibited good mechanical properties and high thermal stability. Furthermore, the cured resins showed low dielectric constants (2.49 at 10 MHz) and low dielectric losses (10 −3 at 10 MHz). Good comprehensive properties of ADM-PBSC may be attributed to its UV/thermally dual cross-linked structure.
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
Polymer Chemistry
·
2025
·
IF 3.9
Xianqiang Zeng,Chen Liu,Xue Wang,Yan Cao,Zheng Zheng,Peng He,Huiquan Li,Liguo Wang
Poly(1,2-butylene oxide) (PBO) with ethyl side chains exhibits enhanced hydrophobicity, lower glass transition temperatures, and more nonpolar characteristics compared to poly(propylene oxide) (PPO). However, the presence of large steric hindrance from side groups of 1,2-butylene oxide (BO) makes its ring-opening polymerization (ROP) inefficient. We report a metal-free Lewis pair catalytic system comprising triethylborane (Et3B) and tetrabutylphosphonium bromide (TBPBr) that overcomes these limitations. This catalyst enables quantitative BO conversion under mild conditions (−20 °C), delivering high molecular weight PBO with a narrow polydispersity index (Mn = 37.2 kg mol−1, Đ = 1.07) through controlled chain propagation. Notably, the exceptional active hydrogen tolerance of the system allows precise synthesis of low molecular weight PBO polyols (Mn = 1.4–3.5 kg mol−1, Đ ≤ 1.05) using diols as initiators, with MALDI-TOF analysis confirming hydroxyl end-group fidelity. Furthermore, PBO polyols can be used directly in the synthesis of polyurethanes without the need for refining. We examined the influence of interactions between Lewis acids and Lewis bases on polymerization, and the results indicate that moderate interaction is critical for achieving optimal polymerization activity. This research demonstrates that a rational combination of a two-component Lewis pair catalyst offers a straightforward and practical approach for synthesizing polyethers with long side chains.
研究领域:
有机化学
·
高分子化学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Yang Li,Chunyan Ma,Hongling Yang,Zhongshen Zhang,Xin Zhang,Nanli Qiao,Junhui Wang,Zhengping Hao
The traditional reaction temperatures of 1-butene isomerization to 2-butene tend to above 100 °C, while here we report the unique catalytic performance of a Pd loaded silica nanospheres catalyst for 1-butene double-bond-shift isomerization at room temperature and showed 2-butene yield of 37.0%. Furthermore, the introduction of O 2 into the reaction mixture dramatically improved the yield efficiency to 57.2% without the formation of by-product CO 2 . The reaction process is proved that the ratio of trans -2-butene to cis -2-butene in the final product was determined by the trans : cis ratio of the butenylcarbenium ion intermediate, and the ratio of trans -2-butene to cis -2-butene decreased with the increasing reaction temperature. Unlike other palladium catalyst systems, Pd 0 nanoparticles were proved to act as catalytic active sites, and their oxidation and aggregation resulted in a decrease in activity. Most importantly, the catalyst acidity affected the catalytic performance, which provides theoretical basis for the choice of catalysts.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Qiuyun Fu,Wei Ding,Ruofan Liu,Yushun Jin,Yibo Wu
In the field of cationic polymerization, ferric chloride (FeCl 3 ) has demonstrated exceptional initiation activity but is plagued by inherent structural instability. Consequently, enhancing the stability of this Lewis acid catalyst while preserving its high reactivity represents a critical research challenge with significant practical implications. This study introduces a novel approach by utilizing the [FeCl 3 ∙i-Pr 2 O] complex as a co-initiator, achieving a one-step protocol for the living cationic polymerization of isobutylene (IB) to produce highly reactive polyisobutylene (HRPIB) with α-olefin content reaching up to 94 %. The research systematically investigates the polymerization kinetics by examining the effects of isopropyl ether (i-Pr 2 O) content, reaction time, solvent polarity, and monomer concentration. Through comprehensive 1 H NMR structural analysis and Gaussian 09 computational simulations, the study reveals that i-Pr 2 O plays a dual-functional role: it not only stabilizes the FeCl 3 active centers but also promotes polyisobutylene chain termination, ultimately yielding three distinct olefin-terminated polyisobutylene derivatives. Building upon this innovative polymerization strategy, the research successfully demonstrates the synthesis of a PIBVE-b-PIB-b-PIBVE triblock copolymer using the [tBuDiCumCl] [FeCl 3 ∙i-Pr 2 O] initiation system.
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
Russian Journal of Physical Chemistry A
·
2025
·Vol. 98
·期 13
·3009-3016
·
IF 0.8
Zhe Wang,Li Junzhi,Zhao Wei,Li Xiao Liang
The isobaric vapor-liquid equilibrium data for the four systems consisting of 1-octene + 2-methyl-thiophene, cyclohexene + 2-methylthiophene, 2,3-dimethyl-1-butene + 2-methylthiophene, and 2,3-dimethyl-2-butene + 2-methylthiophene were determined by using a modified Rose-Williams equilibrium still at 90.00 kPa. All the vapor-liquid equilibrium data measurements passed the thermodynamic consistent test by employing the Herington method. The azeotropic behavior was observed in the 1-octene + 2-methyl-thiophene system. Additionally, the experimental data were correlated by the Wilson model, and they were also compared with the original UNIFAC and UNIFAC Dortmund predictive models. All the results indicated that the measured data were in good agreement with the calculated values obtained from the Wilson. Meanwhile, the UNIFAC Dortmund model can provide better prediction result than the original UNIFAC model.
研究领域:
化学工程
·
热力学
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产品关联
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 5
·3033-3038
·
IF 3.9
Yi-Jie Wang,Yu-Fen Bao,Xiao-Jie Lu,Jia-Qi Dong,Ding-Hua Liu
An SBA-15 loaded CuSO4 catalyst was designed and prepared for the highly selective production of 2,6-di-tert-butyl-p-cresol (BHT) from p-cresol and isobutylene. The acidity of solid acid catalysts was altered by varying the loading amount of CuSO4. Among them, 10% CuSO4/SBA-15 exhibited the greatest catalytic performance in the alkylation reaction with a BHT yield of 85.5%. After four cycles, the yield of BHT exceeded 70%. Overall, the catalyst has excellent catalytic performance and can be utilized as a catalyst for efficient BHT production.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2016
·Vol. 33
·期 7
·2097-2106
·
IF 1.408
Bai Ting,Zhang Xin,Liu Xiling,Chen Tengfei,Fan Wentao
A series of HZSM-5 catalysts were synthesized by different methods. The physicochemical properties of the HZSM-5 catalysts were characterized by XRD, SEM, N2 isothermal adsorption-desorption, NH3-TPD, Py-IR and TGA, respectively. The results indicated that different preparation conditions lead to different morphologies, textures and the distribution of acid sites. The nanosized HZSM-5 catalysts exhibited better catalytic reactivity and coke capacity than the micro-sized HZSM-5 because nanosized HZSM-5 had larger specific surface area, higher pore volume, more exposed channels and more accessible acid sites. The large particles of NZ-3 in a reasonable range and the smooth surface were conducive to product diffusion; therefore, NZ-3 exhibited higher specific propylene yield and stability than the other nanosized catalysts. The moderate density and distribution of acid sites on NZ-3 also favored the formation of propylene.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 3
·640
·
IF 3.9
Cong Wang,Gang Li,Hongchen Guo
MOFs have attracted widespread attention in the field of catalytic ethylene dimerization. Compared with post-synthetic modification, ion exchange and other methods to introduce external active centers, the direct use of MOF materials as catalysts is still the most convenient and prospective. Herein, the NiBTCs are synthesized using a one-pot method in two kinds of solvent and characterized by XRD, FT–IR, ICP–OES, XPS, TGA and N2physical adsorption. After treatment at 150 °C, the catalytic activities of both materials in ethylene dimerization are up to 470.9, and 647.0 gpro./(gcat.·h) and the selectivity of 1-butene in all products could reach 83.2% and 81.7%, respectively. Stability testing of the catalysts demonstrated that they do not decompose during the reaction, but their reuse performance is degraded. In addition, a probable Cossee–Arlman–type mechanism is proposed. The NiBTCs are shown to have superior catalytic performance in ethylene dimerization compared to employing Ni(pyz)2Cl2or α–Ni(im)2as catalysts.Keywords:ethylene dimerization;NiBTCs;MOFs;1-butene
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2014
·
IF 3.679
Yuming Cui,Na Liu,Yifen Xia,Jiangang Lv,Sujuan Zheng,Nianhua Xue,Luming Peng,Xuefeng Guo,Weiping Ding
1-Butene, abundant but inexpensive in industry, can be used to produce more valuable propene and ethene through the well-known metathesis reaction. In terms of catalyst system of molybdena, controlling the interaction between the molybdena and the support is quite crucial. A special support, i.e., well-shaped one-dimensional γ-Al 2 O 3 with uniform diameters of ∼10 nm and lengths of ∼100 nm, has been synthesized via oleylamine-assisted hydrothermal method. The molybdenum oxides are well controlled in sizes of moderate aggregation suitable for 1-butene metathesis with a fairly high rate of propene production (38.9 × 10 −9 mol m −2 s −1 , 30 mol% yield in a single pass) under mild conditions. The status of MoO x species in the catalyst has been investigated by solid state 29 Si MAS NMR, Raman, UV–vis, H 2 -TPR and NH 3 -TPD techniques. The catalyst, highly stable after twelve times of regeneration, is important for practical utilization for the metathesis reactions.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
·
2025
·Vol. 41
·期 3
·1-11
·
IF 4.2
Liu Ming-Yu,Wang Yu-Yue,Li Han-Zhi,Luo Xue-Mei,Feng Jia-Xun,Zhao Shuai
Nitriles exhibit acute cytotoxicity to human and animal cells. Nitrilase is a green biocatalyst that can directly convert nitrile into nontoxic carboxylic acids and ammonia. However, the nitrilases capable of degrading 3-butenenitrile and 4-pentenenitrile derived from glucosinolate present in rapeseed meals are still limited. This study expressed the nit rilase 2 gene from bacterium Paraburkholderia g raminis ( PgNIT2 ) in Escherichia coli . The purified recombinant nitrilase rPgNIT2 showed specific activities of 5.94 U/mg and 6.66 U/mg when using 3-butenenitrile and 4-pentenenitrile as substrates at the optimal pH 7.0 and temperature 45 °C. The substrate binding pocket of PgNIT2 comprising 12 amino acids was required for rPgNIT2 activity. Remarkably, the specific activity of mutant enzyme A190I increased by 68.3% and 57.3%, respectively, against 3-butenenitrile and 4-pentenenitrile compared with the wild-type enzyme. Furthermore, the A190I showed improved thermostability and hydrolysis ability towards 3-butenenitrile and 4-pentenenitrile compared with rPgNIT2 but shared the same optimal pH and temperature. These results provided theoretical guidance for engineering of bacterial nitrilases used for rapeseed meal detoxification.
研究领域:
生物化学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Lubricants
·
2022
·Vol. 10
·期 8
·189
·
IF 3.584
Jiju Guan,Chao Gao,Zhengya Xu,Lanyu Yang,Shuiquan Huang
Developing high-efficiency lubricant additives and high-performance green cutting fluids has universal significance for maximizing processing efficiency, lowering manufacturing cost, and more importantly reducing environmental concerns caused by the use of conventional mineral oil-based cutting fluids. In this study, a nanocomposite is synthesized by filling sulfurized isobutylene (T321) into acid-treated carbon nanotubes (CNTs) with a liquid-phase wet chemical method. The milling performance of a nanocutting fluid containing CNTs@T321 composites is assessed using a micro-lubrication technology in terms of cutting temperature, cutting force, tool wear, and surface roughness. The composite nanofluid performs better than an individual CNT nanofluid regarding milling performance, with 12%, 20%, and 15% reductions in the cutting force, machining temperature, and surface roughness, respectively. The addition of CNTs@T321 nanocomposites improves the thermal conductivity and wetting performance of the nanofluid, as well as produces a complex lubricating film by releasing T321 during machining. The synergistic effect improves the cutting state at the tool–chip interface, thereby resulting in improved machining performance.
研究领域:
材料科学
·
机械工程
·
绿色制造
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）