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anionic polymerization of fluorine-substituted phenyl methacrylates

Science China Chemistry 2015年第1期58卷 107-113页

作者： Bin Li Pan Zhou Yuefei Chen Biao Jiang Hongping Zhu State Key Laboratory of Physical Chemistry of Solid Surfaces National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters College of Chemistry and Chemical Engineering Xiamen University

Synthesis and anionic polymerization of the fluorine-substituted phenyl methacrylates are herein reported. A series of monodi-, and multi-substituted fluorophenyl methacrylates H2C=C（CH3）C（O）OC6H4F-4 （M^1a）, H2C=C（CH3）C（O）OC6H4F-3 （M^1b）, HEC=C（CH3）C（O）OC6H3F2-2,4 （M^2）, H2C=C（CH3）C（O）OC6H2F3-2,3,4 （M^3）, H2C=C（CH3）C（O）OC6HF4-2,3,5,6 （M^4）, and H2C=C（CH3）C（O）OC6F5 （M^5） were synthesized and characterized. Initially, the polymerization was carded out on the monomer M^1a by using nBuLi, tBuLi, and KH as the respective catalysts; this approach produced the polymers in yields of 12%-50%, but with lower molecular weights. Similar results were obtained by using tBuLi for catalytically polymerizing the other five monomers. By introducing a co-catalyst MeAl（BHT）2, the catalysts Nail, LiH, and tBuOLi each were tested to polymerize M^1a, which gave the polymers in very low yields （3%-7%）. Polymer yields of 13%-27% were obtained by each of the catalysts LiAlH4, nBuLi, PhLi, and tBuLi in connection with MeAI（BHT）2, but a better yield （61%） was achieved with KH/MeAl（BHT）2. The KH/MeAl（BHT）2 catalyst system was further employed to polymerize M^1b and M^2, which afforded respective polymer yields of 12%-63% and 10%-53%, depending on the molar ratios of KH：MeAl（BHT）2 as well as on the monomer concentrations. All of the polymers produced were syndiotactically rich in structure, as indicated by either ^1H or ^19F NMR data. The polymerization mechanism by the combined catalyst system is proposed.

关键词： fluorophenyl methacrylates the combined catalyst system anionic polymerization syndiotactic polymer,^1H and ^19F NMR data

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anionic polymerization of Butadiene Using Lithium/Potassium Multi-metallic Systems:Influence on polymerization Control and Polybutadiene Microstructure

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Chinese Journal of Polymer Science 2020年第4期38卷 357-362,I0006页

作者： Antoine Forens Kevin Roos Charlotte Dire Benoit Gadenne Stephane Carlotti Univ.Bordeaux CNRSBordeaux INPLCPOUMR 5629F-33600PessacFrance MFP Michelin Centre de Technologie/Ladoux23 Place des Carmes Dechaux63040 Clermont-Ferrand cedex 9France

Thermal,mechanical,and viscoelastic properties of polybutadiene-based rubber materials are highly dependent on polybutadiene *** use of polar modifier in association with alkyllithium is a well-known method to obtain polybutadiene with a high vinyl con *** approach is to use bimetallic initiating species such as alkyllithium combined to heavier alkali metal alkoxide(RONa,ROK...).The polymerization control is n evertheless not achieved and several parameters were found to influe nee *** bimetallic in itiating systems based on alkyllithium and a potassium alkoxide,alkyllithium structure,initiator preformation time,and initiator composition were identified as parameters influencing the anionic polymerization process of butadiene and/or polybutadiene *** addition,the use of trimetallic systems based on alkyllithium,potassium alkoxide,and alkylaluminum was investigated in order to prevent side reactions regardless of the[K]/[Li]ratio and of the initiator preformation time.

关键词： Polybutadiene anionic polymerization Microstructure (Multi)metallic systems Lithium/potassium-based systems

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anionic polymerization OF ALKYL METHACRYLATES INITIATED BY nBuCu(NCy_2)Li

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Chinese Journal of Polymer Science 2009年第3期27卷 427-433页

作者：韩丙勇杨万泰 State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology(BUCT)

anionic polymerization of methyl methacrylate (MMA), n-butyl methacrylate (nBMA) and glycidyl methacrylate (GMA) initiated by nBuCu(NCy2)Li (1) in tetrahydrofuran (THF) at -50 degrees C to -10 degrees C was investigated. It was found that the polymerization of MMA and nBMA initiated by 1 proceeded quantitatively in THF to afford PMMA and PBMA with polydispersity index 1.15-1.30 and nearly 100% initiator efficiencies at -10 degrees C. The molecular weights increased linearly with the ratio of [monomer]/[1]. However, a post-polymerization experiment carried out on this system revealed a double polymer peak by GPC when fresh monomer was added after an interval of 10 min. polymerization of styrene could be initiated by 1, but the initiator efficiency was low.

关键词： anionic polymerization Lithium organocuprates Alkyl methacrylate

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SYNTHESIS OF HETEROARM STAR POLYMERS COMPRISING POLY(4-METHYLPHENYL VINYL SULFOXIDE) SEGMENT BY LIVING anionic polymerization

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Chinese Journal of Polymer Science 2010年第5期28卷 819-828页

作者：赵优良 Key Lab of Organic Synthesis of Jiangsu Province College of ChemistryChemical Engineering and Materials ScienceSoochow University

A series of 3-arm ABC and AA＇B and 4-arm ABCD, AA＇BC and AA＇A＂B heteroarm star polymers comprising one poly（4-methylphenyl vinyl sulfoxide） segment and other segments such as polystyrene, poly（a-methylstyrene）, poly（4-methoxystyrene） and poly（4-trimethylsilylstyrene） were synthesized by living anionic polymerization based on diphenylethylene （DPE） chemistry. The DPE-functionalized polymers were synthesized by iterative methodology, and the objective star polymers were prepared by two distinct methodologies based on anionic polymerization using DPE-functionalized polymers. The first methodology involves an addition reaction of living anionic polymer with excess DPE-functionalized polymer and a subsequent living anionic polymerization of 4-methylphenyl vinyl sulfoxide （MePVSO） initiated from the in situ formed polymer anion with two or three polymer segments. The second methodology comprises an addition reaction of DPE-functionalized polymer with excess sec-BuLi and a following anionic polymerization of MePVSO initiated from the in situ formed polymer anion and 3-methyl-1,1-diphenylpentyl anion as well. Both approaches could afford the target heteroarm star polymers with predetermined molecular weight, narrow molecular weight distribution （Mw/Mn 〈 1.03） and desired composition, evidenced by SEC, 1H-NMR and SLS analyses. These polymers can be used as model polymers to investigate structure-property relationships in heteroarm star polymers.

关键词： Star polymer anionic polymerization Macromonomer DPE chemistry.

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SYNTHESIS AND CHARACTERIZATION OF RANDOM OR GRADIENT BUTADIENE-p-METHYLSTYRENE COPOLYMERS VIA anionic polymerization

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Chinese Journal of Polymer Science 2013年第12期31卷 1647-1659页

作者： Feng Liu Hai-ying Tan 唐涛 State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of Sciences Graduate School of the Chinese Academy of Sciences

Copolymers of 1,3-butadiene and p-methylstyrene （p-MS） were synthesized via anionic polymerization. A benzophenone-potassium complex was added to tune the reactivity ratio of the two monomers, leading to random and gradient composition alonglthe copolymer chain. The overall composition and microstructure could be controlled and well characterized by GPC and H-NMR. The p-MS was distributed from gradient to random with increasing the content of the benzophenone-potassium complex, and the 1,2-microstrucmre in the polybutadiene sequence increased at the same time. The hydrogenation of the copolymer of 1,3-butadiene and p-MS resulted in the corresponding saturated copolymer with well- defined structure and narrow molecular weight distribution.

关键词： anionic polymerization Butadiene p-Methylstyrene Random copolymer Gradient copolymer.

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The Kinetic Study on the anionic polymerization of Isoprene

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Chinese Journal of Chemical Engineering 1999年第2期7卷 154-160页

作者：程珏韩丙勇杨华何辰凤金关泰北京化工大学材料科学与工程学院北京

The kinetic study of the anionic polymerization of isoprene is carried out in tetrahy-drofuran(THF), using n-BuLi as initiator. Kinetic parameters are obtained, which comprise chain propagation rate constant, kp, and partial rate constants, k3 and k4 + k5, propagation orders with respect to monomer and active species concentrations, α and β, real activation energy, E, as well as partial activation energies, E3 and E4+5 and so on. The relationship between the microstruc-ture of polyisoprene and the ratio of [THF]/[n-BuLi] has been investigated. On the basis of the studies mentioned above, a reasonable mechanism of the anionic polymerization of isoprene in THF is proposed.

关键词： anionic polymerization isoprene kinetics microstructure

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SYNTHESIS OF HYDROXYL-TERMINATED POLYBUTADIENE POSSESSING HIGH CONTENT OF 1,4-UNITS VIA anionic polymerization

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Chinese Journal of Polymer Science 2010年第5期28卷 715-720页

作者：鲁在君 School of Chemistry and Chemical Engineering Shandong University

The hydroxyl-terminated polybutadiene （HTPB） possessing high content of 1,4-units was synthesized by anionic polymerization of butadiene, using alkyllithium containing silicon-protected hydroxyl group as initiator and cyclohexane as solvent. The polymers were characterized by GPC, IR and 1H-NMR. The mechanical properties of cured films were also evaluated. The results show that the content of 1,4-units for HTPBs made by anionic polymerization reaches up to 90%. The molecular weight distribution is very narrow （〈 1.05）. The functionality of hydroxyl groups approaches 2. Compared with free radical HTPB, the elongation at break of anionic HTPB films increased by 70%, while the tensile strength remained nearly unchanged. This new HTPB can be very useful in solid propellant.

关键词： Hydroxyl-terminated polybutadiene anionic polymerization 1,4-Unit Mechanical properties.

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Helical Poly(α,β-unsaturated ketone)with Bulky Pendant of Binaphthyl from anionic polymerization of(−)-Menthyl(S)-6'-Acrylyl-2'-methyloxy-1,1'-binaphthalene-2-carboxylate

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Chinese Journal of Chemistry 2014年第3期32卷 241-247页

作者： Yehui Chen Liwen Yang Nianfa Yang Zhusheng Yang Jin Zhang Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education College of ChemistryXiangtan UniversityXiangtanHunan 411105China

(−)-Menthyl(S)-6'-acrylyl-2'-methyloxy-1,1'-binaphthalene-2-carboxylate(3)was synthesized and anionically polymerized using n-BuLi as an initiator in *** monomer 3 was levorotatory and had an[α]_(D)^(25)value of−72.4,but its corresponding polymer poly-3 was dextrorotatory and showed an[α]_(D)^(25)value of+***-3 was confirmed to exist in the form of one-handed helical structure in solution by means of comparing the specific optical rotation and the CD spectra with that of 3 and the model compounds such as(−)-menthyl(S)-6'-propionyl-2'-methyloxy-1,1'-binaphthalene-2-carboxylate 2b and(−)-menthyl(S)-6'-heptanoyl-2'-methyloxy-1,1'-binaphthalene-2-carboxylate *** conclusion was also confirmed by the fact that the g-value of poly-3 is about 11 times of that of monomer 3.

关键词： chiral α,β-unsaturated ketone synthesis anionic polymerization helical polymer

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A New View of the Initiation and Propagation in anionic polymerization

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Chinese Journal of Chemistry 2013年第3期31卷 393-400页

作者： Anna Zheng Bo Chen Dihang Hu Yong Guan Dafu Wei Shuzhao Li Dandan Ji Shanghai Key Laboratory of Advanced Polymeric Materials Key Laboratory for Ultrafine Materials ofMinistry of Education School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 China

This work confirms the new view of the initiation and propagation mechanism of the anionic polymerization previously proposed, based on the investigation of anionic bulk-polymerization of styrene and α-methyl styrene with the help of a self designed microflow device and characterized by GPC and in situ ^7Li NMR. It was found that n-BuLl tended to form the hexameric-aggregated structure and even to form the huge aggregated structure based on the former. These aggregations of initiators could directly initiate the anionic polymerization and form the su-pramolecule aggregations. The supramolecule aggregations inevitably blocked the diffusion of the monomers to the ion-pairs and resulted in a stationary-conversion platform. Then the aggregators were dissociated completely into equal binary-aggregated species, and the polymerization continued again rapidly before the termination. Tetrahy-drofuran （THF） acted as the electron donator, which could push the electron cloud to Li cation and make the aggre- gated ring of the active species rather loosened and facilitated the monomer to insert in. Therefore, a little THF can greatly promote the anionic polymerization. However, further addition of THF might block the channel between the ion-pairs and decrease the propagation rate. It was also found that the aggregated structure of the active species during the anionic polymerization only depends on the initiator aggregations which were formed before the polym-erization.

关键词： anionic polymerization initiation mechanism in situ 7^Li NMR organolithium supramolecular aggre-gator

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A Novel Efficient Ligand in anionic polymerization at Elevated Temperature

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Chinese Journal of Chemistry 2014年第11期32卷 1128-1134页

作者： Bo Chen Jiming Wang Minze Shu Bin Zou Yong Guan Anna Zheng Shanghai Key Laboratory of Advanced Polymeric Materials Key Laboratory for Ultrafine Materials of Ministry of EducationSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

This work confirmed a novel ligand in the anionic polymerization,lithium phenoxide,which helped to improve the controllability of the *** stability of n-BuLi against THF at 0℃ was effectively improved by adding lithium *** than 60%n-BuLi in THF was alive with the presence of lithium phenoxide after stirring at 0℃ for 20 min,compared to 2%under same conditions but without lithium *** propagation of polymerization of styrene(St)and methyl methacrylate(MMA)were retarded after adding lithium *** by adding more than 10 fold lithium phenoxide,completed conversion was achieved in the polymerization of MMA in THF at 0℃.The lithium phenoxide showed both promoting and inhibiting effects in the polymerization of isoprene(Ip):it promoted the formation of 3,4-structure,while mitigated the formation of 1,2-and 1,*** general,the polymerization rate of Ip was promoted by lithium phenoxide.

关键词： ligand anionic polymerization kinetics organolithium

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