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Binuclear aluminum complexes Supported by Linked Bis(β-diketiminate) Ligands for Ring-Opening Polymerization of Cyclic Esters

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Chinese Journal of Polymer Science 2018年第2期36卷 190-201页

作者： Shaogang Gong Peng Du Haiyan Ma Shanghai Key Laboratory of Functional Materials Chemistry and Laboratory of Organometallic Chemistry School of Chemistry and Molecular EngineeringEast China University of Science and Technology

Binuclear aluminum alkyl complexes 2a–4g supported by linked bis（β-diketiminate） ligands were synthesized via the reaction of AlEt3 or AlMe3 and the corresponding proligand in a 2：1 molar ratio with moderate yields. The isolated complexes were well-characterized by ^1H-NMR, ^13C-NMR and elemental analysis. The binuclear nature of aluminum complex 2b was further confirmed by an X-ray diffraction study. All complexes 2a–4g could efficiently initiate the ring-opening polymerization（ROP） of ε-caprolactone in toluene. The substituents at the aromatic rings and the linker unit in the auxiliary ligands exerted significant influence on the catalytic behavior of the investigated aluminum complexes. complex 4g（R^1 = R^2 = Cl） containing propylenyl bridging unit exhibited the highest catalytic activity among these complexes, which might be attributed to the increased electrophilicity of the metal center as well as more opened coordination sphere. The molecular weights of obtained poly（ε-caprolactone）s deviating considerably from the theoretical values indicated that the ROP of ε-caprolactone by complexes 2a–4g was not well-controlled, which was also judged from the broad molecular weight distributions（MWD = 1.47-2.47） of produced poly（ε-caprolactone）s. These complexes proved to be inactive toward the polymerization of rac-lactide alone. In the presence of alcohol the polymerization occurred, which was actually initiated by the decomposition species of the aluminum complex upon the treatment with isopropanol.

关键词： Bis(β-diketiminate) ligand aluminum complex Binuclear Polymerization Cyclic ester

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Bimetallic aluminum complexes Supported by Bis(salicylaldimine) Ligand: Synthesis, Characterization and Ring-opening Polymerization of Lactide

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Chinese Journal of Polymer Science 2018年第2期36卷 149-156页

作者： Tong Shi Quan-De Zheng Wei-Wei Zuo Shao-Feng Liu Zhi-Bo Li Key Laboratory of Biobased Polymer Materials Shandong Provincial Education Department School of Polymer Science and Engineering Qingdao University of Science and Technology State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Donghua University

Two types of bifunctional bis（salicylaldimine） ligands（syn-L and anti-L） were designed and synthesized to support bimetallic aluminum complexes. Owing to the rigid anthracene skeleton, syn-L and anti-L successfully locked two Al centers in close proximity（syn-Al2） and far apart（anti-Al2）, respectively. The distance between two Al centers in syn-Al2 was defined by X-ray diffraction as 6.665 ？, which is far shorter than that in anti-Al2. In the presence of stoichiometrical Bn OH, syn-Al2 and anti-Al2 were both efficient for ring-opening polymerization（ROP） of rac-LA with the former being more active. In the presence of excess Bn OH, syn-Al2 showed an efficient and immortal feature, consistent with high conversions, matched Mns, narrow molecular weight distributions and end group fidelity, while anti-Al2 had a much lower activity or even became entirely inactive due to rapid decomposition, indicated by in situ ～1H-NMR experiments of Al complexes with Bn OH.

关键词： Bimetallic catalyst aluminum complex Ring-opening polymerization Immortal polymerization Polyester

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Thermal Stability,Thermal Decomposition and Mechanism Analysis of Cycloaliphatic Epoxy/4,4'-dihydroxydiphenylsulfone/aluminum complexes Latent Resin Systems

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Journal of Wuhan University of Technology(Materials Science) 2012年第6期27卷 1061-1067页

作者：吴松全 LIU Shaozhu 刘宇艳 ZHU Qi WEI Huige School of Chemical Engineering and Technology Harbin Institute of Technology

The thermal stability of latent resin systems, cycloaliphatic epoxy/4,4＇- dihydroxydiphenylsulfone/aluminum complexes, was investigated by dynamic differential scanning calorimetry （DSC） analysis. Experiments were conducted under non-isothermal condition in a nitrogen atmosphere at the heating rate of 10, 20, 30 and 40 ℃/min, respectively. TG curves showed that, in the temperature range of 25 to 600 ℃, the stability of the resin systems could be enhanced by increasing the length of the aliphatic chain in the initiator. Both the Kissinger method and the Ozawa-Flyrm-Wall method were employed to calculate activation energies of the decomposition reaction, and the values obtained from the two methods were compared. Moreover, the corresponding reaction mechanism was identified by the Achar differential method and the Coats- Redfem integral method. The experimental results showed that these four methods were reliable and effective to study the kinetics of the thermal decomposition reaction; and the most probable thermal decomposition mechanism of the resin systems we proposed was found to comply with Mampel power law （m=1）.

关键词： epoxy resin aluminum complex phase separation thermal decomposition

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Controlled Ring-opening(Co)Polymerization of Renewable Macrolactones by Al-based Catalysts with Different Sidearms

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Chinese Journal of Polymer Science 2023年第11期41卷 1706-1713,I0006页

作者： Wu-Chao Zhao Jing Yuan Jiang-Hua He Yue-Tao Zhang State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China

It remains a challenging task to achieve ring-opening(co)polymerization(ROP)of ***,we synthesized a series of Al-based catalysts and systemically investigated the effect of N-containing substituent on the sidearms on ROP of ***3 possessing Nmethyl group could effectively achieve controlled ROP of pentadecalactone(PDL)and macro(di)lactone ethylene brassylate(EB)in combination with BnOH,furnishing polyethylene-like PPDL and PEB with M_(W)up to 90.3 and 321 kg/mol,*** copolymerization of PDL and small-ring lactonesε-caprolactone(e-CL)andδ-valerolactone(δ-VL)could prepare random copolyesters with tailored T_(m)in the range of 57-94℃by controlling the ratios of PDL and e-CL,*** importantly,well-defined block copolyesters could be obtained by sequential adding PDL andε-CL,δ-VL,which have been proved by GPC-MALLS,DSC and^(13)C-NMR.

关键词： Ring-opening(co)polymerization Macrolactones Polyethylene-like polymers Sidearm effect aluminum complex

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Environmental Impact Assessment of HF Emission in South of Iran by Gaussian Atmospheric Dispersion Model

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Journal of Environmental Science and Engineering 2011年第2期5卷 227-233页

作者： T.T. Moghaddam P.G. Saptarshi R.S. Gavali S. Mohammadnejad Department of Environmental Sciences University of Pune Pune 411007 India School of Earth Sciences University of Solapur Solapur 413255 India Department of Environmental Affairs Ministry of Industries ＆ Mines Tehran 4617 Iran

Iran, as a developing country has been facing rapid growth in the energy demanding sectors and needs to achieve essential elements of sustainable development. Environmental impact assessment of factories which emit hazardous gases such as HF would promise a fruitful future to achieve sustainable development. This study reveals an environmental impact assessment that has been carried out for an aluminum complex to be located in south of Iran. Application of Gaussian model showed that the highest concentration at the center of HF plume is 2.65 gr/sec; whereas the average wind speed is 9.1 Knots, the emission rate is 1.24 gr/sec, downwind distance 400 m and the atmospheric stability is in A class. For unstable atmospheric conditions the amount of HF emission comes to be one forth of Iran＇s national standard. It is also suggested that real-time monitoring of the pollutant particles and emissions, together with adapting proper mitigation plans and management skills, will lead to maximum efficiency with the least harmful environmental impacts.

关键词： Environmental impact assessment Gaussian model aluminum complex HF emission

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