检索结果-南通市图书馆

A NOVEL METHOD FOR CHARACTERIZING THE WHOLE PROCESS OF polymer GELATION

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2001年第4期19卷 335-339页

作者： Qiang Chen Xian-min Zhang Guo-wei Wang Jian Xu State Key lab.ratory of polymer phys.cs & chem.stry, Center for Molecular Science, Institute of chem.stry, Chinese Academy of Sciences Beijing 100080, China Department of Information & Electronic Engineering Zhejiang University, Hangzhou 310027, China Tjanjin Polytechnic University,Tianjin 300160 Chinese Acad Sci Ctr Mol Sci State Key Lab Polymer Phys & Chem Beijing 100080 Peoples R China Zhejiang Univ Dept Informat & Elect Engn Hangzhou 310027 Peoples R China

A novel method was established to investigate the gelation process of polymers. The change of refractive index of a polymer system during gelation was determined in situ in a prismatic cell. It can give reliable information on the whole gelation process. The apparatus and the execution of this technique are illustrated and the error is also discussed.

关键词： gelation process in situ technique refractive index

LOW POTENTIAL ELECTROpolymerIZATION OF ANISOTROPIC CONDUCTIVE POLYTHIOPHENE FILMS AND FABRICATION OF ELECTRICAL DEVICES

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 1999年第2期17卷 99-111页

作者： Xiao-bo Wan Yun Lu Xiao-rong Liu Liang Zhou Shi Jin Gi Xue Department of polymer Science and Engineering, the State Key lab.ratory of Coordination chem.stry, Nanjing University, Nanjing 210093, China Nanjing Univ Dept Polymer Sci & Engn State Key Lab Coordinat Chem Nanjing 210093 Peoples R China

The Complexation of thiophene with a Lewis acid with moderate acidity as a solvent, such as BF3-ethyl ether (BFEE) remarkedly lowered the electrochem.cal polymerization potential. The positively charged metal surface of electrode in the process of electrochem.cal deposition enhanced the coordination interaction between pi-electrons of thiophene unit and the metal, which makes thiophene rings lie parallel to the surface of electrode, resulting in a highly ordered polymeric structure. Because of the large intra-chain transfer integrals, the transport of charge is believed to be principally along the conjugated chains, which is much greater than the inter-chain hopping. The specific electrical resistance across the polythiophene film thickness is more than 10(4) times than that along the surface plane of the film. In this paper we review the recent development of polymerization technique by low potential electrochem.cal method performed in our lab.and several electrical devices in which the compact polythiophene films, such as anionic and cationic sieves, and laminate film junction of undoped polythiophene derivatives were used.

关键词： conductive polymer polythiophene anisotropy electric device film junction

MORPHOLOGICAL STUDY ON THE ORIENTED CHITOSAN FILM OBTAINED FROM PRE-SHEARED LIQUID CRYSTALLINE SOLUTION IN DICHLOROACETIC ACID

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2001年第4期19卷 385-390页

作者： Zhong-ming Hu Li-heng Wu Da-cheng Wu Shou-xi Chen State Key lab.ratory of polymer phys.cs and chem.stry, Center for Molecular Science, Institute of chem.stry Chinese Academy of Sciences, Beijing 100080, China China Textile Academy Beijing 100025, China Textile College, Sichuan University Chengdu 610065, China China Text Acad Beijing 100025 Peoples R China Chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Polymer Phys & Chem Beijing 100080 Peoples R China Sichuan Univ Coll Text Chengdu 610065 Peoples R China

The oriented chitosan films obtained from pre-sheared liquid crystalline chitosan/dichloroacetic acid (DCA) solutions were studied by means of polarized optical microscopy (POM), scanning electron microscopy (SEM), infra-red dichroism technique and wide angle X-ray diffraction (WAXD). The sheer induced band texture in the film was found to correspond to the sinusoidal fibrillar microstructure along the shearing direction on the basis of POM and SEM observations. The sinusoidal fibril was found to be lying within the film plane. The model of chitosan molecular orientation in the pre-sheared film with band texture can be established assuming that the main chain orients in the shearing direction and the side group is perpendicular to the shearing direction. The WAXD azimuthal scanning at 2 theta = 20 degrees indicates that the (002) plane orients perpendicular to the shearing direction.

关键词： chitosan morphology orientation shear induced band texture liquid crystalline solution

INFLUENCE OF DIALKYLZINC IN RARE-EARTH TERNARY CATALYST ONTHE COpolymerIZATION OF CARBON DIOXIDE AND PROPYLENE OXIDE

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2005年第6期23卷 671-674页

作者： Dong Xie Xian-hong Wang Xiao-jiang Zhao and Fo-song Wang polymer Material Engineering lab.Changchun Institute of Applied chem.stry,Graduate School of Chinese Academy of Sciences,Changchun 130022,China Chinese Acad Sci Changchun Inst Appl Chem Polymer Mat Engn Lab Grad Sch Changchun 130022 Peoples R China

Rare-earth ternary catalysts Y（CCl3COO）3-ZnR2-glycerin were prepared for the copolymerization of carbon dioxide and propylene oxide （PO）, where dialkylzincs （ZnR2） were diethylzinc, di（n-propyl）zinc, di（n-butyl）zinc, di（i-propyl）zinc, di（i-butyl）zinc, di（s-butyl）zinc,respectively. The Y（CCl3COO）3-ZnR2-glycerin catalysts displayed the highest catalytic activity at the molar ratio of Y（CCl3COO）3：ZnR2：glycerin = 1：20：10. In the same copolymerization condition, catalysts containing dialkylzincs with branched alkyl group showed lower catalytic activity than that with primary alkyl group. For those catalysts including dialkylzincs with primary alkyl group, their catalytic activity decreases with increasing number of carbon atom in the alkyl group with the following sequence： Y（CCl3COO）3-ZnEt2-glycerin 〉 Y（CCl3COO）3-Zn（n- Pr）2-glycerin〉Y（CCl3COO）3-Zn（n-Bu）2-glycerin. However, the alkyl group in the dialkylzinc does not influence the insertion of PO into the propagation chain end.

关键词： Carbon dioxide Propylene oxide Copolymerization Dialkylzinc

polymerization　of　Acrylonitrile　Initiated　by　Di（2，6－di－tert－butyl－4－methylphenoxo）　Samarium　Complex

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 1995年第2期13卷 144-146页

作者：扈晶余齐贵中沈琪 ACAD SINICA CHANGCHUN INST APPL CHEMRARE EARTH CHEM & PHYS LABCHANGCHUN 130022PEOPLES R CHINA

The polymerization of acrylonitrile initiated by organolanthanide complexes alone is studied for the first time. The effect of polymerization conditions on catalytic activity of the title complex and molecular weight ... 详细信息

关键词： Samarium complex Acrylonitrile polymerization

Effect of Polyvinylidene Fluoride Hollow Fiber Membranes on Mass Transfer of Samarium

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2000年第3期18卷 165-168页

作者：罗芳张凤君李德谦吴庸烈 Chinese Acad Sci Inst Appl Chem Lab Rare Earth Chem & Phys Changchun 130022 Peoples R China

The influence of swelling and stripping acidity on the mass transfer coefficient based on water phase and the inner diameters of membranes were studied with P507-HCl-Sm as working system in the two different kinds of hollow fiber membranes. Effects of extractant concentration, H+ concentration in aqueous phase and Sm3+ concentration on extraction rate were discussed and the corresponding reaction series were obtained. According to the investigations on the interfacial kinetics, the reaction kinetics equation and reaction rate constant were obtained.

关键词： rare earths samarium extraction polyvinylidene fluoride hollow fiber membrane mass transfer kinetics

Hydroxyapatite/Metal Composite Coatings Prepared by Two-step Electrodeposition Method

在线全文

学校读者我要写书评

暂无评论

Chinese chem.cal Letters 1998年第4期9卷 403-406页

作者： Jian Min ZHANG Chang Jian LIN Zu De FENG Zhao Wu TIAN(State Key lab. for phys.cal chem.stry of Solid Surface, Institute of phys.cal chem.stry, Department of chem.stry, Department of Materials Science, Xiamen University, Xiamen 361005) Xiamen Univ Dept Chem State Key Lab Phys Chem Solid Surface Inst Phys ChemDept Mat Sci Xiamen 361005 Peoples R China

A two-step electrodeposition method was developed to prepare hydroxyapatite/metal composite coatings. Hydroxyapatite coatings were fabricated by electrochem.cal deposition and post-treatment with alkaline solution, and then cobalt was electrodeposited to form hydroxyapatite/cobalt composite coatings to improve its mechanical properties of bonding strength.

关键词： hydroxyapatite electrodeposition composite coating

Synthesis and characterization of star-comb polybutadiene and poly(ethylene-co-butene)

在线全文

学校读者我要写书评

暂无评论

Chinese chem.cal Letters 2010年第3期21卷 361-364页

作者： Zhang, Hong Xia Li, Yang Zhang, Chun Qing Hu, Yan Ming Wang, Yu Rong Ma, Hong Wei Li, Wei Dalian Univ Technol Sch Chem Engn Dept Polymer Sci & Engn State Key Lab Fine Chem Dalian 116012 Peoples R China

A novel star-comb polybutadiene(SC-PB) was synthesized with n-butyllithium(n-BuLi) as initiator,epoxidized star liquid polybutadiene(ESPB) as coupling agent,cyclohexane as solvent by living anionic polymerization and grafting-onto technology. The SC-PB was subsequently hydrogenated by homogeneous catalysis(catalytic hydrogenation using nickel naphthenate/ triisobutyl aluminum),to transform the SC-PB into the corresponding star-comb poly(ethylene-co-butene)(SC-PEB).The SC-PB was characterized by SEC-TALLS,~1...

关键词： Anionic polymerization Grafting reaction Epoxy group Star-comb polymer Hydrogenation

Bond valence parameters linearly dependent on the molybdenum oxidation states

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第12期47卷 978-981页

作者： Mingdan Chen Zhaohui Zhou Shengzhi Hu Xiamen Univ Dept Chem Inst Chem Phys State Key Lab Phys Chem Solid Surfaces Xiamen 361005 Peoples R China

Based on the availab.e crystal data, a linear correlation between R0, the bond valence parameter for a Mo-containing chem.cal bond, and the Mo oxidation state n was developed for the first time. Using the 'universal' value of the parameter B = 0.037 nm, the linear equations of R0-n for Mo-X (X: O, S, N, Cl and F) bonds were established. The oxidation-state independent Mo-O bond valence parameters, R0 = 0.18788 nm and B = 0.03046 nm, published recently have been shown to be a special case of the linearly correlated functions. Some bond valence sum calculations in compounds containing only Mo-O bonds using these parameters are presented.

关键词： bond valence parameter Mo-O bond oxidation state valence sum rule.