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SURFACE MODIFICATION OF CaCO_3 WITH DENDRITIC CARBOXYLIC ACIDS

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Chinese Journal of polymer science 2002年第3期20卷 231-235页

作者： Zhao-xia Guo Jian Yu Institute of polymer science and Engineering department of chemical Engineering Tsinghua University beijing 100084 China Tsing Hua Univ Dept Chem Engn Inst Polymer Sci & Engn Beijing 100084 Peoples R China

Nanometer calcium carbonate was modified with Frechet type polyether dendrons bearing a COOH group at thefocal point by a wet-coating technique in dichloromethane at room temperature. The interaction between CaCO;and thedendritic modifier was proven by IR and mass spectroscopy of the modified CaCO;after thorough extraction withdichloromethane. The amount of tightly bonded organic modifier was estimated by TGA. It was shown that the amount ofbonded molecules decreased with increasing generation number due to the larger number of branches. Compared tounmodified CaCO;, the modified CaCO;possess different dispersibility in water and in organic solvents.

关键词： calcium carbonate surface modification polyether dendrimer dendritic carboxylic acid

Atom Transfer Radical polymerization of Methyl Methacrylate with α,α-Dichlorotoluene or α,α,α-Trichlorotoluene as Initiator

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Chinese chemical Letters 1999年第7期10卷 611-614页

作者： Zhi Feng FU Yan SHI Ming Zhi HUANG Shu Ke JIAO(department of polymer science. beijing University of chemical Technology. beijing 100029) beijing Univ Chem Technol Dept Polymer Sci Beijing 100029 Peoples R China

The atom transfer radical polymerization (ATRP) of methyl methacrylate using α.α dichlorotoluene or α.α.α-trichlorotoluene as the initiator and CuCl/2.2'-bipyridine complex as the catalyst was investigated. α,α-Dichlorotoluene gave good control of molecular weight with high initiation efficiency and low polydispersity. While α.α.α-trichlorotoluene gave very slow polymerization rate. which could be improved by the addition of Cu (0) to the system.

关键词： atom transfer radical polymerization (ATRP),methyl methacrylate initiator

Synthesis of Bis(4'-hydroxyphenyl)-toluene-2, 4-diurethane for Main Chain Liquid Crystalline Poly(urethane-ester)s

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Chinese chemical Letters 1998年第5期9卷 439-442页

作者： Yan Qing LIAN Ming Qi LI Qi Xiang ZHOU De Shan LIU(Institute of polymer science and Engineering, department of chemical Engineering,Tsinghua University, beijing 100084) Tsing Hua Univ Dept Chem Engn Inst Polymer Sci & Engn Beijing 100084 Peoples R China

A new methodology was advanced that mesogenic cores appeared after theformation of urethane groups and during the monomer-to-polymer transition. A newdiphenol monomer, bis(4'-hydroxy-phenyl)-toluene-2 (BHPTU), was obtainedby the reaction of 2,4-tolulene diisocyanate with hydroquinone in dioxane or N,N-dimethyl-acetandde. The reaction process was monitored by FTIR, and the product was investigated bylH NMR and elemental analysis (EA). A liquid crystalline poly(urethane-ester) was obtainedusing the BHPTU monomer.

关键词： liquid crystalline polymer poly(urethane-ester) synthesis

PHASE SEPARATION BEHAVIOR OF ACRYLONITRILE-BUTADIENE-STYRENE COpolymer INDUCED BY SURFACES OF VARIOUS polymerS

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Chinese chemical Letters 1992年第9期3卷 755-758页

作者： Guo Quan WANG Yao Ting CHEN department of polymer science,beijing Institute of chemical Technology,beijing 100029

This paper reports the phase separation behavior of ABS films cast on the surfaces of homopelymers or random *** is found that phase separation of ABS films was induced by the surfaces of the substrate *** relationship between the miscibility of the sub- strate polymers and the phase separation behavior of ABS films was also examined.

关键词： ABS PHASE SEPARATION BEHAVIOR OF ACRYLONITRILE-BUTADIENE-STYRENE COpolymer INDUCED BY SURFACES OF VARIOUS polymerS POI Poly

Soluble Eggshell Mebrane Protein:Antibacterial Property and Biodegradability

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Journal of Wuhan University of Technology(Materials science) 2007年第1期22卷 117-119页

作者：弋峰于建 Institute of polymer science and Engineering Department of Chemical EngineeringSchool of Materials Science and EngineeringTsinghua University

The antibacterial property and biodegradability of soluble eggshell membrane protein （SEP） are reported. Unlike the natural eggshell membrane （ESM）, SEP does not possess antibacterial property against E. coli. The... 详细信息

关键词： doluble eggshell membrane protein antibacterial property biodegradability

SYNTHESIS AND CHARACTERIZATION OF A NOVEL BLUE LIGHT EMITTING ROD-COIL DIBLOCK OLIGOMER

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Chinese Journal of polymer science 2002年第5期20卷 401-407页

作者： Lifang Yang Haifeng He Hongqing Cao Xinhua Wan Qi-feng Zhou department of polymer science & Engineering College of Chemistry & Molecular Engineering Peking University beijing 100871, China Peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China

Four new rod-coil diblock molecules, which had well-defined para-phenylene oligomers (PPP, from biphenyl to quinquephenyl) as rigid segments and poly(ethylene oxide) (PEO, M-w ca. 750) as flexible segments, were synthesized. The chemical structure and the number of repeating unit in PEO coil and PPP rod were characterized by H-1-NMR and MALDI-TOF mass spectrometry. The diblock oligomers showed good solubility in common organic solvents and aggregated in water as characterized by a blue shift in UV-vis absorption spectra, a red shift in emission spectra, quenching of the fluorescence and formation of the microfibrilla and fractal-like structures. The formation of different supramolecular structures meant that this effort might lead to commercial important highly organized functional materials.

关键词： rod-coil diblock oligomer MALDI-TOF mass spectrometry microfibrilla aggregate fractal-like pattern

INFLUENCES OF ACID POST-TREATMENT ON THE MORPHOLOGY OF SOAP-FREE P(MMA-EA-MAA)PARTICLES PREPARED BY SEEDED EMULSION polymerIZATION

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Chinese Journal of polymer science 2005年第5期23卷 479-485页

作者： Kai Kang Cheng-you Kan Yi Du De-shan Liu department of chemical Engineering,School of Materials science and Engineering,Tsinghua University,beijing 100084,China Tsinghua Univ Dept Chem Engn Sch Mat Sci & Engn Beijing 100084 Peoples R China

Soap-free poly（methyl methacrylate-ethyl acrylate-methacrylic acid） latex particles with narrow size distribution were synthesized by seeded emulsion polymerization, and the porous particles were created by a stepwise alkali/acid treatment method. Effects of acid treatment conditions on the particle morphology were investigated. Results show that one to three pores were formed inside most of particles after post-treatment. At pH 7.0, when the treatment temperature was lower than 70℃, the size of particles and the volume of pores remained almost unchanged, and these two values increased significantly when the temperature was higher than 70℃. Both the particle size and the pore volume decreased with the increase of initial pH value and treatment time in the acid treatment. As the pH was below 4.0 and the treatment time was longer than 180 min, the particles shrunk in size.

关键词： Soap-free emulsion polymerization Particle morphology Porous structure Acid treatment Methyl methacrylate based copolymer.

A General Procedure for Surface Modification of Nano-alumina and Its Application to Dendrimers

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Journal of Wuhan University of Technology(Materials science) 2007年第3期22卷 453-456页

作者：王斌郭朝霞 Institute of polymer science and Engineering Department of Chemical EngineeringSchool of Materials Science and EngineeringTsinghua University

A general procedure for surface modification of nano-alumina using N, N＇-dicyclohexyl- carbodiimide （DCC） mediated amidation is reported. Aliphatic and aromatic carboxylic acids reacted smoothly with nano-alumina pretreated with 3-aminopropyltriethoxysilane in the presence of DCC, giving modified aluminas having organic surfaces. The grafted aluminas have been characterized qualitatively by FT-IR or ^13C CPMAS NMR spectroscopy, and quantitatively by thermogravimetric analysis and elemental analysis. The procedure was applied to polyether dendrons bearing carboxyl groups at the focal points, giving successful grafting of dendrimers onto nano-alumina.

关键词： nano-alumina N, N'-dicyclohexyl-carbodiimide (DCC) surface modification dendrimers

Measurement of Monomer Reactivity Ratios of D,L-3-Methylglycolide with Glycolide or D,L-Lactide

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Chinese chemical Letters 2000年第9期11卷 815-818页

作者： Chang Ming DONG Kun Yuan QIU Zhong Wei GU Xin De FENG department of polymer science and Engineering, College of Chemistry and Molecular Engineering, Peking University, beijing 100871 National Research Institute for Family Planning, beijing 100081 Peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China Natl Res Inst Family Plannning Beijing 100081 Peoples R China

For monomer reactivity ratios study, the copolymerization of D,L-3-methylglycolide (MG) with glycolide (GA) or D,L-lactide (LA) was carried out in bulk to a certain low conversion in the presence of stannous octoate at 140 degrees C. The copolymer compositions were determined by H-1 NMR spectroscopy. The monomer reactivity ratios were evaluated by Fineman-Ross method, Kelen-Tudos method and linear least-squares method. The monomer reactivity ratios of D,L-3-methylglycolide and glycolide or D,L-lactide are r(mg)= 0.73, r(ga)= 1.47; r(mg)= 1.71, r(la)= 0.92, respectively.

关键词： D,L-3-methylglycolide glycolide D,L-lactide ring-opening copolymerization monomer reactivity ratios