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Chinese Journal of Polymer Science 2002年第4期20卷 361-368页

作者： Jie-bin Pang Chang-ming Dong Kun-yuan Qiu Yen Wei Department of Polymer Science and Engineering College of Chemistry and Molecular Engineering Peking University Beijing 100871, China Department of Chemistry Drexel University Philadelphia, Pennsylvania 19104, USA Peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China Drexel Univ Dept Chem Philadelphia PA 19104 USA

Ti-incorporated mesoporous silica materials with pore diameters of 3-4 nm have been prepared via the co-hydrolysis and co-condensation reactions, that is the sol-gel reactions, of titanium (IV) tetrabutoxide and tetraethylorthosilicate in the presence of tartaric acid as template, followed by extraction with ethanol to remove the templatemolecules. The materials were characterized in detail by Fourier transform infrared spectroscopy, nitrogen adsorption-desorption test, powder X-ray diffraction, transmission electron microscopy and X-ray energy dispersive spectroscopy. Theresults indicate that the Ti-containing silica materials have large specific surface areas (ca. 1200 m^2 g^(-1)) and pore volumes(ca. 0.900 cm^3 g^(-1)). The mesoporosity arises from disordered interconnecting channels or pores. The Ti-incorporated silicasexhibit catalytic activity for the ring-opening polymerization of ε-caprolactone, otherwise, the pure mesoporous silicamaterial shows no catalytic activity under the identical conditions.

关键词： Mesoporous material Ti-incorporated silica ε-caprolactone Ring-opening polymerization Sol-gel reactions

Enolic Schiff Base Zinc Amide Complexes： Highly Active Catalysts for Ring-Opening Polymerization of Lactide and ε-caprolactone

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Chinese Journal of Polymer Science 2018年第10期36卷 1123-1128页

作者： Chen-Yang Hu Ran-Long Duan Jing-Wei Yang Shu-Jun Dong Zhi-Qiang Sun Xuan Pang Xian-Hong Wang Xue-Si Chen Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China University of Chinese Academy of Sciences Beijing 100049 China Department of Materials Science and Engineering Jilin University Changchun 130025 China VIP Department Stomatological Hospital of Jilin University Changchun 130021 China

A series of zinc silylamido complexes based upon NNO tridentate enolic Schiff base framework have been synthesized and characterized. These complexes were tested for the ring opening polymerization of lactide and e-caprolactone, exhibiting notably high activity at ambient temperature, The influence of imine bridge length and substituents of diketone over the course of polymerization was investigated in details. Remarkably, 4a was confirmed to be a rare example of exceedingly active and robust zinc catalysts, achieving major transformation of lactide under extremely low loading （0.025 mol%） within 18 rain. The influence of various monomers as well as the polymerization mechanism have also been discussed.

关键词： Zinc β-Diketone Ring-opening polymerization Lactide ε-caprolactone

RING-OPENING POLYMERIZATION OF ε-caprolactone BY LANTHANOCENE CATALYSIS

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Chinese Journal of Polymer Science 1998年第4期16卷 297-303页

作者：孙俊全潘智达杨士林 Department of Chemical Engineering Zhejiang University Hangzhou 310027 China Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China

Ring-opening polymerization of ε-caprolactone (CL) catalyzed bylanthanocenes, O(C_2H_4C_5H_3CH_3)_2YCl (Cat-YCl) and Me_2Si[(CH_3)_3SiC_5H_3]_2NdCl(Cat-NdCl) has been carried out for the first time. It has been found that both yttroceneand neodymocene are very efficient to catalyze the polymerization of CL, giving high molec-ular weight poly (ε-caprolactone) (PCL ). The effects of [cat] / [ε- CL] molar ratio, polymeriza-tion temperature and time, as well as solvents were investigated and polymerization tem-perature is found to be the most important factor affecting the polymerization. The bulkpolymerization gives higher molecular weight PCL and higher conversion than that in solu-tion polymerization. NaBPh_4 was found to promote the polymerization of ε-caprolactone,and thus to increase both the polymerization conversion and MW of poly (ε- caprolactone ).

关键词： Ring-opening polymerization ε-caprolactone Lanthanocene catalyst Rare-earth catalysts Biodegradable material

RING-OPENING POLYMERIZATION OFε-caprolactone USING LANTHANIDE TRIS(N-PHENYL-3,5-DI-T-BUTYLSALICYLALDIMINATO)S AS SINGLE COMPONENT CATALYST

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Chinese Journal of Polymer Science 2007年第5期25卷 541-544页

作者：沈之荃 Institute of Polymer Science Key Laboratory of Macromolecule Synthesis and Functionalization Ministry of EducationZhejiang University

Ring-opening polymerization of ε-caprolactone has been carried out by using rare earth Schiff base complexes： lanthanide tris（N-phenyl-3,5-di-t-butylsalicylaldiminato）s [Ln（OPBS）3] as single component catalyst for the first time. The influences of different rare earth elements, monomer and catalyst concentration as well as reaction time on the polymerization were investigated. Mechanism studies showed that monomer inserts into the active site with the acyl-oxygen bond scission rather than the break of alkyl-oxygen bond.

关键词： Ring-opening polymerization ε-caprolactone Lanthanide Schiff base complex.

Core-shell Cu@SiO_(2)/SiO_(2) catalyst for 1,6-hexanediol dehydrogenation toε-caprolactone:High activity and stability from core-shell nanostructure

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Nano Research 2023年第10期16卷 12270-12280页

作者： Fengyang Jiang Tian Lan Jiaqiang Sun Guofeng Zhao Yong Lu Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China Key Laboratory of Functional Molecular Solids Ministry of EducationCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China College of Chemistry and Materials Science Anhui Normal UniversityWuhu 241002China

The gas-phase dehydrogenation of 1,6-hexanediol(1,6-HDO)toε-caprolactone(ε-CL)over the high-performance Cu-based catalysts is highly desirable,but with grand challenges,because the Cu nanoparticles(NPs)are easy to be sintered with the low Hüttig temperature(250℃ of reaction temperature).Herein,we report a highly efficient silica-encapsulated nano-Cu catalyst(Cu@SiO_(2)/SiO_(2))prepared via a complexation–impregnation method for the dehydrogenation of 1,6-HDO,exhibiting a 1,6-HDO conversion of 95.3%andε-CL selectivity of 80.0%at 270℃.The catalyst also has the outstanding thermal stability(without sintering up to 270℃ for 100 h on stream),which can be attributed to the effective encapsulation of the SiO_(2)*** addition,the reaction network of 1,6-HDO dehydrogenation is ***,the pyridine-diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and in-situ X-ray photoelectron spectroscopy(XPS)reveal that the Cu^(0) species favor the conversion of 1,6-HDO toε-*** synergistic effect of Cu+and Cu^(0) benefits the conversion ofε-CL to 2-methylcyclopentanone(2-MCPN).This study is beneficial for designing the high-performance Cu-based catalysts for 1,6-HDO toε-CL,understanding the reaction network of 1,6-HDO dehydrogenation over the Cu-based catalysts,and offering a strong foundation for the largescale production ofε-CL.

关键词： core–shell nanostructure Cu-based catalyst 1 6-hexanediol dehydrogenation ε-caprolactone

A convenient method to prepare random LA/CL copolymers from poly(L-lactide) and ε-caprolactone

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Science China Chemistry 2018年第6期61卷 708-714页

作者： Hao Ouyang Kun Nie Dan Yuan Yong Zhang Dongmei Cui Yingming Yao Key Laboratory of Organic Synthesis of Jiangsu Province Suzhou Key Laboratory of Macromolecular Design and Precision Synthesisand State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials College of Chemistry Chemical Engineering and Materials Science Dushu Lake Campus Soochow University School of Chemistry and Chemical Engineering Taishan University State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences

Sequential addition of L-lactide(LA) followed by ε-caprolactone(CL), and simultaneous addition of both monomers, afforded random LA/CL copolymers in the presence of lanthanide aryloxides under mild conditions. Transesterification was proved to play a predominant role in random copolymer formation. Moreover, treatment of poly(L-lactide) with ε-CL led to random copolymer formation, which provides a new strategy not only to prepare random LA/CL copolymers, but also to directly modify PLLA.

关键词： random copolymers lanthanide complex transesterification lactide ε-caprolactone

Enzymatic Synthesis and Characterization of Biodegradable Poly(w-pentadecalactone-co-ε-caprolactone)Copolymers

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Journal of Renewable Materials 2018年第6期6卷 591-598页

作者： Cansu Ulker Yuksel Guvenilir Istanbul Technical University Department of Chemical Engineering34469IstanbulTurkey

As an alternative biodegradable aliphatic polyester,poly(w-pentadecalactone-co-ε-caprolactone)copolymer was synthesized via enzymatic ring-opening polymerization.A new biocatalyst,Candida antarctica lipase B,immobilized onto rice husk ash was used for *** were carried out at various temperatures and periods for varied copolymer compositions in order to obtain the highest molecular weight *** best reaction parameters were found to be 80℃ and 6 hours and molecular weights increased proportionally with the amount of w-pentadecalactone(w-PDL).The molecular structure of copolymer with 75%weight ratio of w-PDL(Mn=19720 g/mol)was characterized by proton and carbon nuclear magnetic resonance spectroscopies(^1H-NMR and ^13C-NMR).Thermal properties of the same copolymer and homopolymers were investigated by differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA).Improved thermal features were shown by addition of w-PDL to the structure and compared with poly(ε-caprolactone)(PCL).Consequently,poly(w-pentadecalactone-co-ε-caprolactone)copolymers were found to be good alternatives to widely used polyester,PCL,with their rapid polymerization tendency,higher molecular weights,and improved thermal features.

关键词： Candida antarctica lipase B immobilized lipase rice husk ash copolymerization enzymatic ring-opening polymerization lactones ε-caprolactone ω-pentadecalactone

Aluminum and Titanium Complexes Containing Pyrrole-imine Ligands: Syntheses, Structures, and Ring-opening Polymerization of ε-caprolactone

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Chinese Journal of Structural Chemistry 2019年第10期38卷 1797-1806,1613页

作者：王亚兰党燕潘荟芬葛宇姜志垒夏升旺李亚红 College of Chemistry Chemical Engineering and Materials Science Soochow University

Syntheses and properties of aluminum and titanium complexes incorporating the pyrrole-imine ligands,N-((1H-pyrrol-2-yl)methyl)-1-(1H-pyrrol-2-yl)methanimine(H2L^1)and 2-cyano-1H-pyrrole(HL^2),have been *** of one equiv of H2L^1 to AlMe3 and AlEt3,respectively results in the formation of dinuclear complexes[Al2(L^1)2 Me2](1)and[Al2(L^1)2 Et2](2).Treatment of Ti(NMe2)4 with one equiv of HL^2 and two equiv of iPrOH or three equiv of BnOH results in the production of complexes[Ti(HL^3)2(OiPr)2](3)and[Ti2(HL^3)2(OBn)6](4)(H2L^3=N,N-dimethyl-1H-pyrrole-2-carboximid-amide).HL^3 anion is an intermediate which is in situ formed from the reaction of HL^2 and Ti(NMe2)*** structures of 1~4 were characterized by single crystal X-ray *** catalytic properties of 1~4 toward ring-opening polymerization(ROP)ofε-caprolactone were *** of the compounds could effectively initiate the polymerization reactions with good activities.

关键词： aluminum titanium pyrrole-imine ε-caprolactone ring-opening polymerization

Polymerization of ε-caprolactone by lanthanide trisborohydrides and crystal structure of [Ce(BH_4)_2(THF)_5][Ce(BH_4)_4(THF)_2]

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Journal of Rare Earths 2012年第8期30卷 753-756页

作者：袁福根李婷婷李理周媛 School of Chemistry and Biochemistry University of Science and Technology of Suzhou

Complexes of lanthanide trisborohydrides, formally Ln（BH4）3（THF）, （Ln=La, Ce, Sm, Yb）, were synthesized and their catalytic activity for polymerization of ε-caprolactone was studied. All the complexes can catalyze this polymerization. It was found that the catalytic activities decreased in the order of La〉Ce〉Sm〉Yb. The crystal structure of cerium trisborohydride was determined for the first time by single crystal X-ray diffraction analysis. It is an ionic pair complex of [Ce（BH4）E（THF）5][Ce（BH4）4（THF）2]. The cationic part involves two ηa-BH4 ligands, while the anionic part involves two η3-BH4 groups and two η2-BH4 groups.

关键词： lanthanide borohydride polymerization catalysis ε-caprolactone rare earths

Ring-opening Polymerization of ε-caprolactone by Lanthanide Tris(2,6-dimethylphenolate)s

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Chinese Journal of Chemistry 2003年第9期21卷 1236-1237页

作者：张丽芳沈之荃于翠萍 Institute of Polymer Science Zhejiang University Hangzhou Zhejiang 310027 ChinaDepartment of Chemistry Shanxi Normal University Linfen Shanxi 041004 China Institute of Polymer Science Zhejiang University Hangzhou Zhejiang 310027 China

Lanthanide tris(2,6-dimethylphenolate)s [Ln(ODMP) 3] were used as initiators for ring-opening polymerization of ε-caprolactone (CL) for the first time. The influence of different rare earth elements and solvents was investigated. 1H NMR spectral data of polycaprolactone (PCL) obtained showed that the polymerization mechanism is in agreement with the coordination-insertion mechanism and the selective cleavage of the acyl-oxygen bond of CL.

关键词： ring-opening polymerization ε-caprolactone lanthanide tris(2,6-dimethylphenolate)