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Kinetics and mechanism studies on scandium calix[6]arene complex initiating ring-opening polymerization of 2,2-dimethyltrimethylene carbonate

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Science China Chemistry 2007年第5期50卷 648-653页

作者： GOU PengFei ZHU WeiPu shen zhiquan Key Laboratory of Macromolecule Synthesis and Functionalization Ministry of Education Institute of Polymer Science Zhejiang University Hangzhou 310027 China Key Laboratory of Macromolecule Synthesis and Functionalization Ministry of Education Institute of Polymer Science Zhejiang University Hangzhou 310027 China Key Laboratory of Macromolecule Synthesis and Functionalization Ministry of Education Institute of Polymer Science Zhejiang University Hangzhou 310027 China

Scandium p-tert-butylcalix[6]arene complex has been synthesized from scandium isopropoxide and p-tert-butylcalix[6]arene and used as a single component initiator for the first time. The polymerization of 2,2-dimethyltrimethylene carbonate (DTC) using this complex can proceed under mild conditions. Poly (2,2-dimethyltrimethylene carbonate) (PolyDTC) with weight-average molecular weight of 33700 and molecular weight distribution of 1.21 can be prepared. Kinetics study indicates that the polymeri- zation rate is first order with respect to both monomer and initiator concentrations, and the apparent activation energy of the polymerization is 22.7 kJ/mol. 1H NMR spectrum of the polymer reveals that the monomer ring opens via acyl-oxygen bond cleavage leading to an active center of Sc-O.

关键词： ring-opening polymerization, scandium calixarene complex, 2,2-dimethyltrimethylene carbonate (DTC), polycarbonates

Room temperature polymerization of alkyl isocyanates catalyzed by rare earth Schiff base complexes

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Science China Chemistry 2009年第11期52卷 1843-1850页

作者： XiongFa Yang XuFeng Ni zhiquan shen Key Laboratory of Macromolecular Synthesis and Functionalization Ministry of Education Institute of Polymer Science Zhejiang University Hangzhou 310027 China

The polymerization of alkyl isocyanates catalyzed by rare earth chloride salen complexes/triisobutyl aluminum (Ln(H2salen)2Cl3·2C2H7OH/Al(i-Bu)3) at room temperature was investigated. The influences of ligand structure, catalyst composition, polymerization temperature, polymerization time, the concentration of catalyst and monomer, and the polymerization solvent on the polymerization of isocyanates were studied. It was found that under the polymerization conditions, examined La(H2salenA)2Cl3·2C2-H7OH/Al(i-Bu)3 (H2salenA= N,N′-disalicylideneethylene diamine) is a fairly high efficient catalyst for the polymerization of n-hexyl isocyanate (n-HexNCO) to prepare high molecular weight poly(n-hexyl isocyanate) (PHNCO) with narrower molecular weight distribution at room temperature. PHNCO could be prepared with yield of 74.0%, number-average molecular weight (M n) of 40.20×104 and MWD of 1.79 under the following optimum conditions: [Al]/[La] = 30 (molar ratio), [n-HexNCO]/[La] = 100 (molar ratio), [n-HexNCO] = 3.43 mol/L polymerization at 20°C for 12 h in toluene. In the same polymerization conditions, poly (n-octyl isocyanate) (PONCO) with yield of 67.3%, and poly(n-butyl isocyanate) (PBNCO) with yield of 45.5%, could be prepared respectively. The kinetics of the polymerization of n-HexNCO was also investigated and found to be first-order with respect to both monomer and catalyst concentrations.

关键词： rare earth catalyst Schiff base complex polymerization alkyl isocyanate

A novel hyperbranched aromatic polyamide containing bithiazole: Synthesis,metal complexation and magnetic properties

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Science China Chemistry 2011年第2期54卷 320-325页

作者： DING NengWen LIN WeiHong SUN WeiLin shen zhiquan Key Laboratory of Macromolecule Synthesis and Functionalization Ministry of EducationDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

Based on the polycondensation of bifunctional 2,2′-diamino-4,4′-bithiazole(DABT) and trifunctional 1,3,5-benzenetricarbonyl trichloride (BTC),a novel hyperbranched aromatic polyamide PBD was synthesized with excellent solubility and good thermal *** structure of the polymer was confirmed by FT-IR and 1H NMR *** calculated degree of branching of our product was 52%.By exploring the influence of several different solvent systems,the yield of the polymer increased in the solvent system of DMAc/*** kinds of metal complexes were obtained by chelation of the polyamide with Cu2+ and Ni2+,and the metal contents of the complexes were determined by complexometric *** magnetic behaviors of the complexes were examined as a function of magnetic field strength at 5 K,and as a function of temperature (5–300 K) at a magnetic field strength of 2.4 × 106 A/*** results indicated that the complexes were soft ferromagnetic materials with Curie-Weiss temperature at 102 K and 53 K,respectively.

关键词： hyperbranched aromatic polyamide synthesis magnetic properties

基于子午流注理论运用揿针早期介入促醒重型颅脑损伤昏迷患者的临床观察

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中华中医药杂志 2024年第3期39卷 1582-1585页

作者：李悦杨玉霞闫馨月胡欣欣倪晓光沈志全沧州市中心医院沧州061000

目的:探讨基于子午流注理论运用揿针埋针法联合康复治疗早期介入促醒重型颅脑损伤昏迷患者的临床疗效。方法:将100例重型颅脑损伤患者随机分为对照组50例和观察组49例(脱落1例)。对照组给予常规重型颅脑损伤后的治疗、用药、康复护理和... 详细信息

目的:探讨基于子午流注理论运用揿针埋针法联合康复治疗早期介入促醒重型颅脑损伤昏迷患者的临床疗效。方法:将100例重型颅脑损伤患者随机分为对照组50例和观察组49例(脱落1例)。对照组给予常规重型颅脑损伤后的治疗、用药、康复护理和康复治疗;观察组在对照组的基础上加用子午流注法揿针治疗,治疗30 d后观察两组的治疗效果,分别在治疗前和治疗后第10、20、30天采用格拉斯哥昏迷量表(GCS)、全面无反应量表(FOUR)和改良国际昏迷恢复量表(CRS-R)进行评估。结果:观察组治疗后各时间点GCS、FOUR及CRS-R的评分高于对照组(P<0.05)。结论:揿针埋针法在子午流注理论基础上联合康复治疗早期介入对于促醒重型颅脑损伤昏迷患者具有积极改善的作用。

关键词：子午流注揿针重型颅脑损伤昏迷早期康复

n-Octyloxyallene homopolymerization and random copolymerization with styrene using catalyst system composed of lanthanide Schiff-base complexes and Al(i-Bu)_3

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Science China Chemistry 2013年第7期56卷 970-976页

作者： JIAO JunQing ZHU WeiWei NI XuFeng shen zhiquan MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University

The catalyst system composed of lanthanide Schiff-base complexes with [3,5-tBu2-2-（O）C6H2CH=NC6Hs]3Ln（THF）（Ln（Salen）3, Ln = Sc, Y, La, Nd, Sm, Gd, Yb） and triisobutyl aluminum shows high activity for n-octyloxyallene （A） homopolymerization with narrow molecular weight distribution （MWD）. The influences of reaction conditions on polymerization behavior are in- vestigated, and poly（n-octyloxyallene） has a weight average molecular weight （Mw） of 20.6 ~ 103 with MWD of 1.39 and 100% yield is obtained under the optimum conditions： [A1]/[Y] = 50 mol/mol, [A]/[Y] = 100 mol/mol, with polymerization at 80 ~C for 16 h in bulk. The kinetic studies of n-octyloxyallene homopolymerization indicate that the polymerization rate is first-order with respect to the monomer concentration and shows some controlled polymerization characteristics. Random co- polymer of n-octyloxyallene with styrene is obtained by using the same binary catalyst system; the reactivity ratios of the comonomer determined by Kelen-Ttld/Ss method are rA = 1.20 and rst = 0.35, respectively, the ratio of each segment and Mw of the resulting copolymer could be controlled by varying the feed ratio of each monomer. Determined by differential scanning calorimetry, the copolymers obtained show only one glass transition temperature, which increases gradually with the increase of styrene content in the copolymer.

关键词： n-octyloxyallene styrene lanthanide Schiff-base coordination polymerization

Amphiphilic Seven-arm Star Triblock Copolymers with Diverse Morphologies in Aqueous Solution Induced by Crystallization and pH

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Chemical Research in Chinese Universities 2018年第1期34卷 132-137页

作者： SUN Rui WANG Ying GOU Pengfei ZUO Min LI Xiaodong ZHU Weipu shen zhiquan Department of Oral and Maxillofacial Surgery Affiliated Stomatology Hospital College of Medicine Zhejiang University Hangzhou 310006 P. R. China Key Laboratory of Macromolecular Synthesis and Functionalization Ministry of EducationDepartment of Polymer Science and Engineering Zhejiang University Hangzhou 310027 P. R. China

Well-defined amphiphilic seven-arm star triblock copolymers containing hydrophobic crystalline poly（e-caprolactoneXPCL） blocks, hydrophobic non-crystalline poly（tert-butyl acrylate）（PtBA） blocks and hydrophilic poly（ethylene glycol）（PEG） blocks were precisely synthesized by a combination of ring-opening polymerization（ROP）, atom transfer radical polymerization（ATRP） and ＂click＂ reaction. Such star copolymers could self-assemble into ＂core-shell-corona＂ micelles and ＂multi-layer＂ vesicles depending on the fraction of each block. Meanwhile, the selective hydrolysis of middle PtBA blocks into the poly（acrylic acidXPAA） blocks allowed the star block copolymers to further change their morphologies of aqueous aggregates m response to pH values.

关键词： Amphiphile Crystallization Hydrolysis Self-assembly Star block copolymer

Donor-Acceptor Oligomers and Polymers Composed of Benzothiadiazole and 3-Hexylthiophene： Effect of Chain Length and Regioregularity

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Chinese Journal of Chemistry 2013年第11期31卷 1367-1379页

作者： Jintu Wang Huaiying Ye Hongjiao Li Chongyu Mei Jun Ling Weishi Li zhiquan shen Laboratory of Organic Functional Materials and Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China Department of Polymer Science and Engineering Zhejiang University Hangzhou Zhejiang 310027 China

A series of donor-acceptor oligomer OBTThn （n = 1- 7） and polymer PBTThl and PBTTh2 composed of al- ternative 2,1,3-benzothiadiazole and 3-hexylthiophene have been designed and synthesized for the purpose of in- vestigation on the effect of chain length and side-chain regioregularity on their basic properties and photovoltaic performance. In the OBTThn oligomers and PBTThl polymer, all the hexyl side chains on thienyl units orient to- ward the same direction. Upon elongation of the chain length, the intramolecular charge transfer （ICT） absorption band in solution gradually redshifts from 398 nm for OBTThl to 505 nm for OBTThT, then to 512 nm for PBTThl polymer. Meanwhile, the HOMO energy level increases from -5.45 eV （OBTTh0 to -5.08 eV （OBTThT） and -5.09 eV （PBTThl）, and the LUMO energy level decreases from -3.11 eV （OBTTh0 to -3.30 eV （OBTThT） and -3.33 eV （PBTThl）, thus giving a smaller and smaller energy bandgap for higher oligomers and polymers. Theo- retical calculation suggests straight line-like backbone geometry for this series of oligomers and polymer. On the other hand, polymer PBTTh2 possesses a different side-chain regioregularity, in which every two neighbor hexyl side chains are arranged in different orienting direction. It is theoretically suggested to have curved line-like back- bone geometry. In solution, it shows similar photophysical and electrochemical properties as PBTThl. However in film state, it displays a less redshift in the ICT band as refer to that in solution than PBTThl. In combination with [6,6]-phenyl-C61-butyric acid methyl ester （PC61BM）, these oligomers and polymers were used as donor material to fabricate organic bulk heterojunction solar cells. Again, chain length-dependent device photovoltaic performance was observed. The device based on OBTTh4 showed a power conversion efficiency of 0.16%, while it increased to 0.36% and 0.49% for the devices based on OBTTh6 and PBTThb respectively. However, the side-chain regio- regularity ha

关键词： conjugated polymers organic solar cells regioregularity donor-acceptor oligomers

Detection of free surface composition and molecular-level structural development of styrene(S)/butadiene(B) block copolymer films during a solution-to-film process

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Science China Chemistry 2012年第7期55卷 1263-1273页

作者： YAN ZhuoHua ZHANG RongPing ZHAO YuRong ZUO Biao ZHENG FanFan CHEN TianYu WANG XinPing shen zhiquan Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education Department of Chemistry Zhejiang Sci-Tech UniversityHangzhou 310018China Institute of Polymer Science Zhejiang UniversityHangzhou 310027China

The surface chemical structure development in solution-cast styrene(S)/butadiene(B) block copolymer films as a function of solvent evaporation time was investigated using sum frequency generation vibrational spectroscopy(SFG).The surface structure formation of the styrene(S)/butadien(B) block copolymer(30 wt% PS) films during the solution-to-film process was found to be controlled mainly by dynamic factors,such as the mobility of the PB block in *** SB diblock copolymers,a pure PB surface layer was formed only when the film was cast by dilute toluene *** increasing concentration of casting solution,PB and PS components were found to coexist on the film surface,and the morphology of the PB component on the film surface changed from cylindrical rods to *** SBS triblock copolymers,a small amount of PS component existed on the surface even if the film was cast by 1.0 wt% toluene *** addition,PS components at the outermost layer of the film increased and the length of PB cylindrical rods on the surface decreased with increasing concentration of casting solution.

关键词： styrene/butadiene block copolymer chain architecture casting solution concentration surface structure sum frequen-cy generation vibrational spectroscopy

Assimilating FY-4A AGRI Radiances with a Channel-Sensitive Cloud Detection Scheme for the Analysis and Forecasting of Multiple Typhoons

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Advances in Atmospheric Sciences 2024年第5期41卷 937-958页

作者： Feifei shen Aiqing SHU zhiquan LIU Hong LI Lipeng JIANG Tao ZHANG Dongmei XU Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 210044China Shanghai Typhoon Institute China Meteorological AdministrationShanghai 200030China China Meteorological Administration Basin Heavy Rainfall Key Laboratory/Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research Institute of Heavy RainChina Meteorological AdministrationWuhan 430205China National Center for Atmospheric Research Boulder 80307COUSA State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China National Meteorological Information Center Beijing 100081China Fujian Key Laboratory of Severe Weather and Key Laboratory of Straits Severe Weather China Meteorological AdministrationFuzhou 350001China

This paper presents an attempt at assimilating clear-sky FY-4A Advanced Geosynchronous Radiation Imager(AGRI)radiances from two water vapor channels for the prediction of three landfalling typhoon events over the West Pacific Ocean using the 3DVar data assimilation(DA)method along with the WRF model.A channel-sensitive cloud detection scheme based on the particle filter(PF)algorithm is developed and examined against a cloud detection scheme using the multivariate and minimum residual(MMR)algorithm and another traditional cloud mask–dependent cloud detection *** show that both channel-sensitive cloud detection schemes are effective,while the PF scheme is able to reserve more pixels than the MMR scheme for the same *** general,the added value of AGRI radiances is confirmed when comparing with the control experiment without AGRI ***,it is found that the analysis fields of the PF experiment are mostly improved in terms of better depicting the typhoon,including the temperature,moisture,and dynamical *** typhoon track forecast skill is improved with AGRI radiance DA,which could be explained by better simulating the upper *** impact of assimilating AGRI radiances on typhoon intensity forecasts is *** the other hand,improved rainfall forecasts from AGRI DA experiments are found along with reduced errors for both the thermodynamic and moisture fields,albeit the improvements are limited.

关键词： FY-4A AGRI radiance particle filter multiple typhoons data assimilation numerical weather prediction