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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,{12. department of polymer {2. & Engineering College of Chemistry & Molecular Engineering Peking University 北京 100871 department of polymer {2. & Engineering College of Chemistry & Molecular Engineering Peking University 北京 100871

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

SYNTHESIS OF NOVEL LIQUID CRYSTALLINE POLY(METH)ACRYLATES CONTAINING SILOXANE SPACER AND TERPHENYLENE MESOGENIC UNIT

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Chinese Journal of polymer science 2000年第2期18卷 101-107页

作者： Zhi-qian Zang Yu-fei Luo Dong Zhang Xin-hua Wan qi-{2. {3. department of polymer science & Engineering, College of chemistry, peking university, beijing 100871, china 北京大学北京

Novel side-chain liquid-crystalline poly(meth)acrylates were synthesized using 1-(3.hydroxyl-propyl)-3.[(4 '-cyano-p-terphenyloxycarbonyl)alkyl]-1,1,3.3.tetramethyldisiloxane as the key intermediate. The polymers used a disiloxane moiety as decoupling spacer with cyano-p-terphenyl as mesogenic unit. The products were characterized by NMR, GPC, DSC and polarizing optical microscopy. All the polymers with cyano-p-terphenyl mesogens formed a stable mesophase. However, if the mesogenic unit is replaced by cyano-p-biphenyl, the liquid crystalline character will be lost. The results also showed that the decoupling is incomplete even if a complex and very flexible decoupling spacer is deliberately incorporated to obtain the highest possible decoupling effect.

关键词： liquid crystalline polymers polyacrylates 4 ''-cyano-p-terphenyl

A DSC STUDY OF PHOTOpolymerIZATION OF POLYESTERS CONTAINING CONJUGATED DIACETYLENES

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Chinese Journal of polymer science 2000年第4期18卷 351-356页

作者： Yao-wen Bai Xiao-fang Chen Dong Zhang Xin-hua Wan qi-feng {2. {3. of polymer science and Engineering, College of chemistry, peking university, beijing 100871, china 北京大学北京

The photopolymerization of two kinds of prepolyesters containing conjugated diacetylene (PDA-6 and PDA-12. was investigated using DSC. By measuring the endothermic enthalpy of the prepolymers after different UV-irradiation times, the polymerizations were found to follow the first-order rate law which agreed with the results of other investigators using a different method. The endothermic enthalpy measurements of PDA-6 and PDA-12.before UV-irradiation precluded the possibility that the decrease of endothermic enthalpy was caused by thermal polymerization.

关键词： diacetylene-containing polyesters DSC enthalpy

“LIVING”/CONTROLLED RADICAL polymerIZATION OF ETHYL METHYLACRYLATE WITH 2.2.-AZOBISISOBUTYRONITRILE/FERRIC CHLORIDE/TRIPHENYLPHOSPHINE INITIATION SYSTEM

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Chinese Journal of polymer science 2000年第2期18卷 149-153页

作者： Xiao-ping Chen Kun-yuan qiu department of {2. {3. and Engineering, College of chemistry, peking university, beijing 100871, china 北京大学北京

'Living'/controlled radical polymerization of ethyl methacrylate (EMA) was carried out with a 2.2.-azobisisobutyronitrile (AIBN)/ferric chloride (FeCl_3./triphenylphosphine (PPh_3. initiation system at 85℃. Thc numberaverage molecular weight (M_n) increases linearly with monomer conversion and the rate of polymerization is first order withrespect to monomer concentration. The M_w of PEMA ranges from 3.00 to 17600 and the polydispersity indices are quitenarrow (1.09～1.2.). The conversion can reach up to～100% and M_w of the polymers obtained is close to that designed. Thepolymerization mechanism belongs to the reverse atom transfer radical polymerization (ATRP). The polymer was end-functionalized by chlorine atom, which acts as a macroinitiator to proceed extension polymerization in the presence ofCuBr/bipy catalyst system via an ATRP process. The presence of ω-chlorine in the PEMA obtained was identified by ~1H-NMR spectrum.

关键词： 'Living'/controlled radical polymerization Reverse ATRP Ethyl methacrylate AIBN/FeCl_3.PPh_3 Bulk polymerization

SYNTHESIS AND PROPERTIES OF LIQUID CRYSTAL POLYSILOXANES WITH MESOGENIC STILBENE SIDE GROUPS

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Chinese Journal of polymer science 2000年第2期18卷 95-99页

作者： Dong Zhang Yan-tao Zhu Da-hui Zhao Xin-hua Wan qi-feng {2. {3. of polymer science & Engineering, College of chemistry, peking university, beijing 100871, china 北京大学北京

A variety of mesomorphic side-chain polysiloxanes were synthesized by using hydrosilylation reaction with dicyclopentadienylplatinum(II) (DPPC) as the catalyst. The mesogenic groups are derivatives of stilbene with cyano or nitro tail groups. The products were characterized by DSC, X-ray diffraction and polarizing optical microscopy (POM). All the polymers were found to have relatively low T-g and can form a smectic liquid crystal phase.

关键词： liquid crystal polymer polysiloxane

SYNTHESIS AND BIOTECHNOLOGICAL APPLICATIONS OF VINYL polymerINORGANIC HYBRID AND MESOPOROUS MATERIALS

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Chinese Journal of polymer science 2000年第1期18卷 1-7页

作者： Yen Wei Kun-yuan qiu department of {2., Drexel {3., Philadelphia, Pennsylvania 19104, USA department of polymer science and Engineering, peking {3., beijing 100871, china Drexel university 美国北京大学高分子科学与工程系北京

We describe the sol-gel synthesis of a new family of organic-inorganic hybrid materials, in which various vinyl polymers are covalently bonded to and uniformly distributed in inorganic oxide matrices. The materials can be tailored to have both good toughness and hardness while maintaining excellent optical transparency. Doping the sol-gel metal oxides with optically active compounds such as D-glucose results in new optical rotatory composite materials. Removal of the dopant compounds from the composites affords mesoporous oxide materials; which represents a new, nonsurfactant-templated route to mesoporous molecular sieves. We have successfully immobilized a series of enzymes and other bioactive agents in mesoporous materials. Catalytical activities of the enzyme encapsulated in mesoporous materials were found to be much higher than those encapsulated in microporous materials.

关键词： vinyl polymer-inorganic hybrid materials mesoporous materials sol-gel process biotech-nological applications

A NOVEL PHOTO-INITIATING SYSTEM FOR ATOM TRANSFER RADICAL polymerIZATION OF STYRENE

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Chinese Journal of polymer science 2001年第5期19卷 441-445页

作者： Shu-hui qin Dong-qi qin Kun-yuan qiu department of polymer science and Engineering College of chemistry and Molecular Engineering peking university beijing 100871, china 北京大学北京

A novel photo-induced initiating system, 2.2.dimethoxy-2.phenylacetophenone (DMPA)/ferric tri(NN-diethyldithiocarbamate) [Fe(DC)(3.], was developed and used for the atom transfer radical {3.ization (ATRP) of styrene in toluene. The {3.ization proceeds with DMPA as photo-initiator, Fe(DC)(3. as catalyst and DC as a reversible transfer group, while the halogen and ligands are free. Well-defined PSt was prepared and the {3.ization mechanism revealed by end group analysis belongs to a reverse ATRP. Block co{3. was prepared by using thus obtained PSt as macroinitiator and Fe(DC)(2. as catalyst under UV light irradiation via a conventional ATRP process.

关键词： photo atom transfer radical polymerization living radical polymerization well-defined polystyrene block copolymer

PROPERTIES OF POLYURETHANE ELASTOMERS BASED ON POLY (OXYETHYLENE-co-OXYTETRAMETHYLENE) DIOL

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Chinese Journal of polymer science 2001年第4期19卷 371-376页

作者： Chen-yu Su Guang-li Zhang Hong-zhi Zhang department of polymer {2. and Engineering College of {3. and Molecular Engineering peking university beijing 100871, china 北京大学北京

Polyurethane elastomers derived from 4,4 ' -methylene bis(phenyl isocyanate), butylene glycol and the low oxyethylene moiety content copolyether of tetrahydrofuran and ethylene oxide, obtained by copolymerization using heteropolyacid-ethylene oxide initiator system, were prepared. The polyurethanes exhibited an increased water absorption and much better low temperature resilience, which remained high even at a temperature of -3.degreesC, while that of polyurethane based upon poly(tetramethylene ether) glycol of the 'same molecular weight, i.e. being 2.00, and molecular weight distribution, i.e, in the range of 1.4-1.5, starts to decrease dramatically at 5 degreesC.

关键词： polyurethane poly(oxyethylene-co-oxytetramethylene) diol low temperature resilience heteropolyacid-ethylene oxide initiator system

Study on the two and three-parameter working stability regions of 3.-TZP suspension

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science china(Technological sciences) 2006年第5期49卷 547-568页

作者： CHEN Youqiang1, 2. ZHANG Xinni3. CHEN Sha’ou3.& qi Ping3.1. {2. of chemistry, qingdao university, qingdao 2.6071, china 2. {2. of chemistry, Tsinghua university, beijing 100084, china 3. {2. of Physics, qingdao university, qingdao 2.6071, china department of chemistry Qingdao University Qingdao China department of chemistry Tsinghua University Beijing China department of Physics Qingdao University Qingdao China

We determined the variation tendency of viscosity (η) at various solids load- ing (α) for 3.-TZP suspension as a function of dispersant concentration (Cw) using vis- cosity measurement, measured the diameter of particles as a function of Cw in very dilute suspension using light scattering method, and obtained the surface features of the sedi- ment of suspension with different Cw using SEM. We also discussed the influence of the microstructure of adsorbed polymer layers on particles and their interactions in the dis- persing medium on the stability of suspension. Then two different stable states and two different unstable states for 3.-TZP suspension were given. Accordingly, the (Cw, η), (Cw, α), and (α, η) two-parameter, and (Cw, α, η) three-parameter stability maps were con- structed. Based on the DLVO theory calculations, the dispersant concentration, particle distance (r), and interparticle potential energy (VT) maps with various solids loading for 3.-TZP aqueous suspension were also constructed. In (Cw, r) two-parameter coordinate system, the stable motion region map for particles was established. The Cw, α, and VT,max (the highest potential energy) surface of the potential barrier map was obtained through calculation and simulation on the basis of the surfaces of Cw, r, VT maps introduced above. The (Cw, α) two-parameter stability map was then obtained from the Cw, α, VT,max map. The results showed that this theoretical map can qualitatively prove the experimentally obtained results—the existence of different dispersed states of particles in suspension system and the variation tendency of suspension stability with changing each parame- ter—were reasonable.

关键词： 3.-TZP, suspension, stability, DLVO theory, interparticle potential energy.