<正>1 Aims and Scope Chinese Journal of Polymer Science (CJPS) is a bimonthly journal published in English and sponsored by the Chinese Chemical Society and the Institute of Chemistry, Chinese Academy of Sciences. CJPS is edited by a distinguished Editorial Board headed by Professor Fosong Wang and supported by an International Advisory Board in which many famous active polymer scientists all over the world are included. The journal was first published in 1983 under the title Polymer Communucations and has the current name since 1985.
Hui Jin, Yan-bing Hou, Xian-guo Meng and Feng Teng Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044, China
2006(6): 553-558.
Published(online):2021-06-21
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In this paper, photoexcitation processes in the bilayer devices based on inorganic materials and poly(N-vinyl-carbazole) (PVK) were investigated. In order to clarify the roles of inorganic materials in photoconductive properties of bilayer devices, TiO2 and ZnS were chosen to combine with PVK. A model for generation of photocurrent (Iph) in single layer device of PVK was obtained. It is deduced that the recombination rate constant (Pcomb) and the ionization rate constant (γ) of excitons should be considered as the most important factors for Iph. For inorganic materials (TiO2 or ZnS)/PVK bilayer devices, in reverse bias of-4 V, the photocurrent of 115 mA/cm2 in the TiO2/PVK device was observed, but the photocurrent in the ZnS/PVK device was only 10 mA/cm2 under the illumination light of 340 nm and the light intensity of 14.2 mW/cm2. The weaker photocurrent is attributed to the absorption of ZnS within UV region and the energy offset at the interface between PVK and ZnS, which impedes the transport of charge carriers.
To improve the water tree resistance of PE, linear low-density polyethylene (LLDPE) was compounded with sodium acrylate (NaAA) for in situ polymerization, in which NaAA was formed through the neutralization of acrylic acid (AA) with sodium hydroxide (NaOH) before adding dicumyl peroxide (DCP) to initiate the in situ graft polymerization and homo polymerization. A series of LLDPE/NaAA compounds were investigated for their water absorption ratio (WAR) measurement, water treeing, mechanical and dielectric properties. The results strongly suggest that NaAA can improve the water tree resistance of LLDPE. In addition, the LLDPE/NaAA compounds possess satisfactory mechanical properties and dielectric properties. Characterization of LLDPE/NaAA compounds by using Fourier transform infrared spectrometry (FTIR) suggests that the neutralization and polymerization reaction could be achieved effectively. Using adequate DCP content is the key factor for controlling the polymerization of NaAA with precise conversion ratio.
Experimental miscibility studies were performed on different compositions of i’PP/sPP blends, where sPP has a low syndiotacticity ([rrrr] = 81%). Combining optical microscopy, rheology, and solid state NMR spectroscopy, the miscibility of the blends was investigated at different scales in the traditionally thought to be "immiscible" iPP/sPP blends. For the composition of iPP/sPP (90/10) blend, it shows to be miscible in the melt, and furthermore, the existence of intermolecular chain interactions between sPP and ;’PP components was detected in the solid state.
Tai-jiang Gui, Hao Wei, Ying Zhao, Xiu-lin Wang, Du-jin Wang and Duan-fu Xu Chemistry and Chemical Engineering College, Ocean University of China, Qingdao 266003, China State Key Laboratory of Polymer Physics and Chemistry, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China Marine Research Institute of Chemical Industry, Qingdao 266071, China
2006(6): 575-578.
Published(online):2021-06-21
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A series of copolymers comprising butylmethacrylate, styrene, butylacrylate, hydroxypropyl acrylate and perfluoroalkyl methacrylate were synthesized by the free radical polymerization using BPO as an initiator. The surface property of the copolymer films was subsequently characterized. The contact angle measurements and energy dispersive analysis of X-ray (EDAX) show that the length and content of perfluoroalkyl side chains in the copolymers are crucial for the preparation of the film with low surface energy. At a given content of fluorinated monomers in the copolymers, the longer the perfluoroalkyl side chain, the larger the water contact angle of the copolymer films will be. On the other hand, the higher the content of fluorinated monomers, the lower the surface energy is. The water contact angle increases with the increase of the fluorinated monomer content and reaches a plateau at 3 wt% of fluorinated monomer content.
Yu-ying Gao and Gao-quan Shi Department of Chemistry, Tsinghua University, Beijing 100084, China
2006(6): 579-584.
Published(online):2021-06-21
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Highly sensitive catalase electrodes for sensing hydrogen peroxide have been fabricated based on polypyrrole films with microcontainers. The microcontainers have a cup-like morphology and are arranged in a density of 4000 units cm-2. Catalase was immobilized into the polypyrrole films with microcontainers (Ppy-mc), which were coated on a Pt substrate electrode. The catalase/Ppy-mc/Pt electrode showed linear response to hydrogen peroxide in the range of 0-18 mmol/L at a potential of-0.3 V (versus SCE). Its sensitivity was measured to be approximately 3.64μA (mmol/L)-1 cm-2, which is about two times that of the electrode fabricated from a flat Ppy film (catalase/Ppy-flat/Pt electrode). The electrode is highly selective for hydrogen peroxide and its sensitivity is interfered by potential interferents such as ascorbic acid, urea and fructose. Furthermore, such catalase electrodes showed long-term storage stability of 15 days under dry conditions at 4℃.
Guan-hua Meng, Ai-min Li, Wei-ben Yang, Fu-qiang Liu and Quan-xing Zhang State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210093, China Engineering Technology Research Center of Organic Toxic Substance Control and Resource Reuse of Jiangsu Province, Nanjing 210038, China
2006(6): 585-591.
Published(online):2021-06-21
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Two hypercrosslinked resins with similar physical characters but different surface chemistry were synthesized and used to remove phenol from aqueous solutions. The FTIR spectra, elemental analysis and the Boehm titration were used to characterize the chemical properties of the resins. The adsorption experiments were carried out using the bottle-point technique, and the effects of the surface chemistry on the adsorption were discussed. The adsorption data fit well with the Freundlich model, indicating the heterogeneity of the resins surface. It could be seen from the experimental results that the adsorption capacity increased with the increase in the total surface concentration of oxygen-containing groups. The pH dependence and the effects of ionic strength were also discussed. The kinetic adsorption data fit well with the pseudo-second order model, and the results showed that the surface oxygen-containing groups have little effect on the adsorption rate.
Qi Wang, Yi-xian Li, Jian Hong and Zhi-qiang Fan Department of Polymer Science & Engineering, Zhejiang University, Hangzhou 310027, China
2006(6): 593-597.
Published(online):2021-06-21
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The novel cyclic trithiocarbonate was synthesized by dialkylation of trithiocarbonate anion with 2,2’-bis(bromomethyl)biphenyl in a two-phase system using an onium salt as a phase-transfer agent. Styrene polymerization was carried out in the presence of cyclic trithiocarbonate (CTTC). CTTC undergoes ring opening-polymerization and the incorporated trithiocarbonate moiety derived from CTTC performs as the reversible addition-fragmentation chain transfer (RAFT) agent. Through this mechanism, multiblock polystyrenes containing various narrow polydispersity blocks can be prepared.
Due to its mechanical properties and ease of use, vinyl ester resin is enjoying increasing consideration. This resin normally is produced by reaction between epoxy resin and unsaturated carboxylic acid. In the present study, bis-phenol A based epoxy resin and methacrylic acid was used to produce vinyl ester resin. The reaction was conducted under both stoichiometric and non-stoichiometric conditions in the presence of triphenylphosphine as catalyst. The stoichiometric and non-stoichiometric experiments were conducted at 95, 100, 105 and 110℃and at 90 and 95℃, respectively. The first order rate equation and mechanism based rate equation were examined. Parameters are evaluated by least square method. A comparison of mechanism based rate equation and experimental data show an excellent agreement. Finally, Arrhenius equation and activation energy were presented.
Shu-xin Huang and Chuan-jing Lu Department of Engineering Mechanics, Shanghai Jiao Tong University, Shanghai 200030, China
2006(6): 609-617.
Published(online):2021-06-21
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The theoretical characterizations on the triangular-form thixotropy-loop tests of an LDPE melt (PE-FSB-23D022/Q200) were conducted in the present paper by using a new thixotropy model, which is constituted by the upper convected Maxwell model and a rate-type kinetic equation. The new thixotropic Maxwell model can partially describe well three reported thixotropy-loop experiments by comparison with the previous calculations of the variant form of the thixotropy-type Huang model. It is noted that the stress deviations between the experiments and the predictions of the new thixotropic Maxwell model are much slighter than those deviations obtained by using the variant Huang model at the same condition, although both models include five parameters. The constitution of the new thixotropic Maxwell model is more reasonable than that of the variant Huang model.
Dan Zhu, Yi-xiang Cheng, Xiao-wei Zou, Ling-wu Chen, Jin-feng Song and Zhi-liu Wang College of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
2006(6): 619-625.
Published(online):2021-06-21
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Chiral polymer was synthesized by the polymerization of (R)-6,6’-bistributylstannyl-2,2’-binaphtho-20-crown-6 (M-1) with 1,4-dibromo-2,3-bisbutoxy-naphthyl (M-2) by Pd(PPh3)4 catalyzed Stille coupling reaction. Both monomer and polymer were analyzed by NMR, MS, FT-IR, UV, polarimetry, DSC-TGA, CD, fluorescent spectroscopy and GPC. The major difference between monomer and polymer is that a long wavelength Cotton Effect was observed for the polymer due to its more extended conjugation in the repeating unit and a highly rigid backbone in the polymer chain. Polymer has strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the repeating unit of the polymer to the chiral binaphthyl core and is expected to have potential application in the materials of fluorescent sensors and chiral chromatographic packing for resolution of racemic amino acid.
Chloromethylation of polystyrene (PS) with two different chloromethylating systems methylal/thionyl chloride and paraformaldehyde/trimethylchlorosilane was studied. Soluble chloromethylated polystyrene with a degree of substitution of 89% was obtained. The Conant-Finkelstein reaction on the chloromethylated PS afforded soluble iodomethylated polystyrene with a degree of substitution as high as 96%. The reaction conditions of Minisci were employed to radically pyridinate PS via its iodomethylated derivative. Polyelectrolytes were formed which could be converted to normal polymers by treatment with a 20% aqueous solution of NaOH.
Qun Chen, Ai-yun Wang, Tian-tong Li, Cheng-fu Li and Qing-cai Jiao State Key Laboratory of Pharmaceutics Biotechnology, School of Life Science, Nanjing University, Nanjing 210093, China Department of Biochemistry, Huainan Teachers’ College, Huainan 232001, China
2006(6): 637-646.
Published(online):2021-06-21
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High purity polysaccharide of pachyman was isolated from the powder of Poria cocos sclerotium with an yield of 77.8%. The intrinsic viscosity of polysaccharide was found to be 78.95 mL/g in DMSO solution at 25℃. The isolated polysaccharide was reacted with chlorosulfonic acid to obtain pachyman sulfate using the improved Wolfram method. The results of the orthogonality experiment on the sulfation reaction identified that the effectiveness of the reaction conditions on the degree of sulfation and the value of intrinsic viscosity is in the following order: molar ratio of chlorosulfonic acid to glucoside (3-5) > reaction temperature (60-80℃) > reaction time (1-2 h). The kinetic studies of the pachyman sulfation indicated that the hydrolysis is accompanied with the sulfation process. The decrease in intrinsic viscosity of the sulfated pachyman is proportional to the increase in the degree of sulfation under the mild reaction conditions of < 80℃, chlorosulfonic acid/glucoside mole ratio < 5, and reaction time < 2 h. Beyond the above reaction conditions, excessive loss of -OH group occurs during hydrolysis. The NMR results indicated a complete sulfation on C-6 and a partial sulfation on the C-2 and C-4 of glucoside.
The oxidative polycondensation reaction conditions of 4-m-tolylazomethinephenol (4-TAMP) in the presence of air O2 and NaOCl as oxidants were studied in an aqueous alkaline medium between 50 and 90℃. The structures of the obtained monomer and oligomer were confirmed by FT-IR, UV-Vis, 1H- and 13C-NMR and elemental analysis techniques. The physical characterization was made by TG-DTA, size exclusion chromatography (SEC) and solubility tests. At the optimum reaction conditions, the yield of oligo-4-m-tolylazomethinephenol (O-4-TAMP) was found to be 62.50% (for air O2 oxidant) and 90.0% (for NaOCl oxidant), respectively. According to the SEC analysis, the number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) values of O-4-TAMP were found to be 2310, 2610 g mol-1 and 1.13, respectively, using air O2, and 1390, 1710 g mol-1 and 1.23, using NaOCl, respectively. According to TG-DTA analyses, O-4-TAMP was more stable than 4-TAMP against thermal decomposition. The weight losses of 4-TAMP and O-4-TAMP were found to be 68% and 58% at 1000℃. Electrical conductivity of the O-4-TAMP was measured, showing that the polymer is a typical semiconductor. Electrochemically, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and electrochemical energy gaps (E’g) for 4-TAMP are -5.96, -3.22 and 2.74 eV, respectively. The HOMO, LUMO and (E’g) for O-4-TAMP are -5.78, -3.44 and 2.34 eV, respectively. According to UV-Vis measurements, optical band gaps (Eg) of 4-TAMP and O-4-TAMP were found to be 3.45 and 3.10 eV, respectively.