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Exploring the effect of cooling rate on non-isothermal crystallization of copolymer polypropylene by fast scanning calorimetry
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作者 Yang Liao Ye-yuan Hu +4 位作者 Kosuke Ikeda Ryoji Okabe Rui-fen Wu Ryota Ozaki Qing-yan Xu 《China Foundry》 SCIE EI CAS CSCD 2024年第4期379-386,共8页
Polypropylene is commonly used as a binder for ceramic injection molding,and rapid cooling is often encountered during processing.However,the crystallization behavior of polypropylene shows a strong dependence on cool... Polypropylene is commonly used as a binder for ceramic injection molding,and rapid cooling is often encountered during processing.However,the crystallization behavior of polypropylene shows a strong dependence on cooling rate due to its semi-crystalline characteristics.Therefore,the influence of cooling rate on the quality of final product cannot be ignored.In this study,the fast differential scanning calorimetry(FSC)test was performed to study the influence of cooling rate on the non-isothermal crystallization behavior and non-isothermal crystallization kinetics of a copolymer polypropylene(PP BC03B).The results show that the crystallization temperatures and crystallinity decrease as the cooling rate increases.In addition,two exothermic peaks occur when cooling rate ranges from 30 to 300 K·s^(-1),indicating the formation of another crystal phase.Avrami,Ozawa and Mo equations were used to explore the non-isothermal crystallization kinetics,and it can be concluded that the Mo method is suitable for this study. 展开更多
关键词 cooling rate crystallization temperature CRYSTALLINITY non-isothermal crystallization kinetics FSC copolymer polypropylene
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The effect of ethylene-vinyl acetate copolymer on the formation process of wax crystals and hydrates
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作者 Limin Wang Jinrong Duan +2 位作者 Bei Liu Zhi Li Guangjin Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第9期109-119,共11页
Ethylene-vinyl acetate copolymer(EVA) as a kind of effective polymeric pour point depressant has been extensively used in the pipeline transportation of crude oil to inhibit wax deposition and improve the low temperat... Ethylene-vinyl acetate copolymer(EVA) as a kind of effective polymeric pour point depressant has been extensively used in the pipeline transportation of crude oil to inhibit wax deposition and improve the low temperature fluidity of crude oil. In this work, molecular dynamics simulations were performed to investigate the effect of EVA on wax-hydrate coexistence system to evaluate the application potentiality of EVA to the flow assurance of deep-sea oil-gas-water multiphase flow system. Our simulation results reveal that wax molecules gradually stretched and stacked from random coiling to a directional and ordered crystalline state during the process of wax solidification. The strong affinity of polar vinyl acetate side chains of EVA to neighboring water molecules made the EVA molecule prefer being in a curly state,which disrupted the ordered crystallization of surrounding wax molecules and delayed the solidification rate of wax cluster. In addition, it is found that EVA cocrystallized with wax molecules to form eutectic when the wax was fully solidified. The simulation results of hydrate nucleation and growth show that the EVA molecule displayed a two-sided effect on gas adsorption of wax crystals, which was the key factor that affected the nucleation and growth of hydrates in the methane-water system. The nonpolar hydrocarbon backbone of EVA increased the diffusion rate of methane and water, allowing more methane to diffuse to the surface of wax crystals, reducing the methane concentration in aqueous solutions and inhibiting the hydrate formation. On the other hand, the nonpolar vinyl acetate chains had a repulsive effect on methane, which reduced the adsorption area of methane on the eutectic surface and decreased the adsorption threshold value of the wax crystal. The excluded methane molecules would continue dissociating in the aqueous phase and participating in the nucleation and growth process of hydrates.Therefore, the probability of hydrate formation would be increased. It was worth noting that the inhibition performance of EVA on hydrate formation mainly played a significant role in the system with small wax crystal, while its hydrate promotion effect played a dominant role in the system with lager wax crystal. In summary, EVA could significantly inhibit both of the wax and hydrate deposition for the waxgas-water multiphase system with low wax content. When the wax content in the system was high, the role of EVA was mainly played in the alleviation of wax crystallization rather than the gas hydrates. The results of the present work can contribute to a better understanding of EVA on wax deposition and hydrate formation, and provide theoretical support of the potential industrial applications of EVA. 展开更多
关键词 Wax crystallization Hydrate formation Ethylene-vinyl acetate copolymer Molecular dynamics simulation
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Hybrid anionic block copolymerization:From organocatalysis-streamlined crossover to internally microphase-separated aggregates
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作者 Lijun Liu Heng Li +3 位作者 Pengfei Zhang Yubo Zhou Junpeng Zhao Guangzhao Zhang 《Aggregate》 EI CAS 2024年第4期226-235,共10页
Polyolefin-b-poly(ethylene oxide)(PEO)represents the most widely investigated amphiphilic block copolymers.So far,one-pot continuous synthesis of such hybrid block copolymers has only been fulfilled by anionic polymeriz... Polyolefin-b-poly(ethylene oxide)(PEO)represents the most widely investigated amphiphilic block copolymers.So far,one-pot continuous synthesis of such hybrid block copolymers has only been fulfilled by anionic polymerization through sequen-tial addition of vinyl monomers and ethylene oxide(EO).It still remains challenging to achieve altogether high block efficiency,high polymerization efficiency,and high molar mass for PEO.Here,we report a one-pot hybrid block copolymerization approach to polyisoprene/polystyrene(PI/PS)-b-PEO,in which PI/PS are formed by sBuLi-initiated anionic vinyl-addition polymerization,then in situ employed as macroinitiators for the anionic ring-opening polymerization(ROP)of EO aided by an organic Lewis pair.The cooperative(dual-ion-complexing)catalytic effect of organobase and triethylborane is proven,for thefirst time,effective for lithium alkoxide initiator system,allowing to achieve at room temperature high ROP activity(complete EO conversion and PEO of 3–64 kg/mol reached in 1–6 h),narrow molar mass distribution,controlled block lengths and composition.Density functional the-ory calculation shows that phosphazene bases are particularly effective,compared with N-heterocyclic bases,for complexing with Li+and enhancing the nucleophilic-ity of oxyanion.The rate of ROP is also affected by Li+-induced aggregation of the chain-end ion pairs,which though can be offset by adequate catalyst loadings.The versatility of this approach is further demonstrated in the one-pot synthesis of tri-/tetrablock ter-/quaterpolymers constituted by PI,PS,PEO,and poly(propylene oxide).Of great interest,PS-b-PI-b-PEO triblock terpolymer with a specific com-position is found to form internally microphase-separated micellar aggregates when dispersed in water. 展开更多
关键词 aggregation anionic polymerization block copolymer ORGANOCATALYSIS ring-opening polymerization
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Syntheses and properties of associative acrylamide copolymers containing short hydrophobic chains used in a friction reducer for slick-water fracturing
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作者 Ya-Xing Dai Xian-Li Zhang +6 位作者 Si-Yuan Liu Feng-Run-Ze Zhang Yi-Xi Zhang Yu-Tong Sang Jing-Xi Zheng Zhao-Sheng Liu Peng Zhang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期1889-1901,共13页
Two allyldimethylalkyl quaternary ammonium salt(AQAS)monomers,N,N-dimethylallylphenylpropylammonium bromide(AQAS1)and N,N-dimethylallylnonylammonium bromide(AQAS2),were synthesized and used to prepare modified polyacr... Two allyldimethylalkyl quaternary ammonium salt(AQAS)monomers,N,N-dimethylallylphenylpropylammonium bromide(AQAS1)and N,N-dimethylallylnonylammonium bromide(AQAS2),were synthesized and used to prepare modified polyacrylamide materials.Two new drag reducers were synthesized from acrylamide(AM),sodium acrylate(Na AA)and a cationic modified monomer(AQAS1 or AQAS2)via aqueous solution polymerization,and the copolymers were named P(AM/Na AA/AQAS1)and P(AM/Na AA/AQAS2),respectively.The structures of the drag reduction agents were confirmed by IR and1H NMR spectroscopies.The molecular weight(Mw)of P(AM/Na AA/AQAS1)was 1.79×10^(6)g/mol.When the copolymer concentration was 1000 mg/L and the flow rate was 45 L/min,in fresh water the highest drag reduction rate was 75.8%,in 10,000 mg/L Na Cl solution the drag reduction rate decreased to 72.9%.The molecular weight of P(AM/Na AA/AQAS2)was 3.17×10^(6)g/mol.When the copolymer concentration was500 mg/L and the flow rate was 45 L/min,the drag reduction rate reached 75.2%,and in 10,000 mg/L Na Cl solution the drag reduction rate was 73.3%,decreased by approximately 1.9%.The drag reduction rate for partially hydrolyzed polyacrylamide(HPAM)was also investigated,and the results showed that the drag reduction rates for 500 and 1000 mg/L HPAM solutions were merely 43.2%and 49.0%in brine,respectively.Compared with HPAM,both of the above copolymers presented better drag reduction capacities. 展开更多
关键词 Shale gas Slick water Drag reducer Modified monomer copolymerIZATION
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A Non-parametric Gradient-Based Shape Optimization Approach for Solving Inverse Problems in Directed Self-Assemblyof Block Copolymers
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作者 Daniil Bochkov Frederic Gibou 《Communications on Applied Mathematics and Computation》 EI 2024年第2期1472-1489,共18页
We consider the inverse problem of finding guiding pattern shapes that result in desired self-assembly morphologies of block copolymer melts.Specifically,we model polymer selfassembly using the self-consistent field t... We consider the inverse problem of finding guiding pattern shapes that result in desired self-assembly morphologies of block copolymer melts.Specifically,we model polymer selfassembly using the self-consistent field theory and derive,in a non-parametric setting,the sensitivity of the dissimilarity between the desired and the actual morphologies to arbitrary perturbations in the guiding pattern shape.The sensitivity is then used for the optimization of the confining pattern shapes such that the dissimilarity between the desired and the actual morphologies is minimized.The efficiency and robustness of the proposed gradient-based algorithm are demonstrated in a number of examples related to templating vertical interconnect accesses(VIA). 展开更多
关键词 Block copolymers Directed self-assembly Inverse design Shape optimization Vertical interconnect accesses(VIA)
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Advancements in Polymer Science: Synthesis, Characterization, and Biomedical Applications of Homopolymers and Copolymers
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作者 Anaif M. Alhewaitey Ishrat Khan Emmanuel Ramsey Buabeng 《Open Journal of Polymer Chemistry》 2024年第3期167-198,共32页
Polymer science encompasses a different range of materials critical to industries spanning from packaging to biomedicine. Understanding the synthesis, characterization, and applications of common homopolymers and copo... Polymer science encompasses a different range of materials critical to industries spanning from packaging to biomedicine. Understanding the synthesis, characterization, and applications of common homopolymers and copolymers is fundamental to advancing polymer research and development. In this comprehensive review, we explore various preparation methods, including free radical, anionic, and cationic polymerization, utilized for synthesizing homopolymers and copolymers. Furthermore, we investigate solvent choices commonly employed for polymer characterization, ranging from neat conditions, polar protic and polar aprotic solvents. We also explored characterization techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR), Atomic Force Microscopy (AFM), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA). In addition to industrial applications, we highlight the diverse biological applications of homopolymers, poly(2-hydroxyethyl methacrylate) (pHEMA) and polystyrene, which find its extensive use in biomedicine. By synthesizing and analyzing this wealth of information, this review aims to provide a comprehensive understanding of the synthesis, characterization, and applications of homopolymers and copolymers, with a particular focus on their biological applications. This holistic approach not only contributes to advancements in polymer science and technology but also fosters innovation in biomedicine, ultimately benefiting human health and well-being. 展开更多
关键词 HOMOPOLYMER copolymer Poly(2-hydroxyethyl methacrylate) (pHEMA) Polystyrene Free Radical Polymerization Atomic Force Microscopy Solvent Polarity
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Influence ofβ-nucleating Compound Agents on the Mechanical Properties and Crystallization Behavior of Polypropylene Random Copolymer 被引量:2
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作者 谷亚新 LIU Yunxue +3 位作者 FAN Zhaorong GUI Jianfeng 刘鹏 WANG Hongmei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第1期237-243,共7页
A novel polypropylene random(PPR)composite materials with optimized properties was developed by addingβ-nucleating compound agents(rare earth complex WBG-2 and aryl amide derivative TMB-5)and ternary compound modifie... A novel polypropylene random(PPR)composite materials with optimized properties was developed by addingβ-nucleating compound agents(rare earth complex WBG-2 and aryl amide derivative TMB-5)and ternary compound modifier(TPE/WBG-2/CaCO_(3)).The effects of differentβ-nucleating agents and ternary compound modifier on the mechanical properties and crystallization behavior of PPR were analyzed.The results show that,compared with pure PPR materials,both WBG-2 and TMB-5 could significantly improve the impact strength of PPR.The crystallization temperature of PPR increased with the addition ofβ-nucleating agent.The modified PPR prepared with ternary compound modifier showed the most excellent comprehensive properties. 展开更多
关键词 polypropylene random copolymer β-nucleating agent impact strength crystallization behavior
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A fast ionic transport copolymeric network for stable quasi-solid lithium metal battery 被引量:2
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作者 Weiqi Mai Qiaoying Cao +4 位作者 Mingtao Zheng Yong Xiao Hang Hu Yingliang Liu Yeru Liang 《Journal of Energy Chemistry》 SCIE EI CSCD 2023年第12期491-500,I0013,共11页
Solid-state lithium(Li) metal batteries overwhelm the lithium-ion batteries by harvesting high energy from Li metal anode with ultrahigh capacities and gaining excellent safety from solid electrolytes.However,the unco... Solid-state lithium(Li) metal batteries overwhelm the lithium-ion batteries by harvesting high energy from Li metal anode with ultrahigh capacities and gaining excellent safety from solid electrolytes.However,the uncontrollable solvents in solid electrolytes usually aggravate poor interfacial contact with lithium metal anode and deteriorate Li^(+) pathways.Here a copolymeric network-structured ion conductor by rationally integrating cellulose nanofibril as a two-in-one functional material is employed to anchor the solvent.Taking advantages of tightly anchoring of cellulose nanofibril to solvent,the asconstructed quasi-solid polymer-based electrolyte offers rapid Li^(+) transport channels and realizes effective Li-dendrite suppression,which enables high ionic conductivity of 1.93 × 10^(-3)S cm^(-1) at room temperature,long-term Li plating/stripping over 1900 h,and high capacity retention of 99%.This work provides a fresh strategy for creating solid electrolytes that meet both high ionic conductivity and interfacial stability requirements for practical solid-state lithium metal battery. 展开更多
关键词 Lithium metal battery Quasi-solid polymer electrolyte Cellulose nanofibrils Solvent anchoring copolymeric network
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Research on the Marine Antifouling Ability and Mechanism of Acrylate Copolymers and Marine Coatings Based on a Synergistic Effect
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作者 ZHOU Wenjun ZHOU Yu +4 位作者 NI Chunhua YU Liangmin YUAN Zhengjun LI Changcheng YAN Xuefeng 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第3期717-727,共11页
Marine biofouling is an urgent global problem in the process of ocean exploitation and utilization.In our work,a series of zinc-based acrylate copolymers(ACZn-x)were designed and synthesized using benzoic acid,zinc ox... Marine biofouling is an urgent global problem in the process of ocean exploitation and utilization.In our work,a series of zinc-based acrylate copolymers(ACZn-x)were designed and synthesized using benzoic acid,zinc oxide(ZnO)and a random quaternion copolymer consisting of ethyl acrylate(EA),butyl acrylate(BA),acrylic acid(AA)and methacrylic acid(MAA)by free radical polymerization and dehydration condensation.The ACZn-x with a zinc benzoate side chain is able to hydrolyze in natural seawater under static conditions,resulting in the formation of a smooth surface.We investigated and confirmed the antifouling(AF)behavior of ACZn-x in the laboratory and revealed that they have better antibacterial(86%for S.aureus and 72%for E.coli)and anti-algal(≥60.1%for N.closterium and≥67.5%for P.subcordiformis)activities.We also assessed the marine AF properties of ACZn-x and corresponding coatings in Qingdao,China;the ACZn-x exhibited ideal AF properties with little silt and biological mucosa adhered to the ACZn-x surface after 6 months,and corresponding coatings exhibited little biofouling after 16 months in the ocean.Importantly,possible AF mechanisms were further proposed at the cellular level.These results could be helpful for the development and application of effective AF coatings. 展开更多
关键词 zinc-based acrylate copolymer self-polishing marine antifouling MECHANISM
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Ethylene Copolymerization with Linear and End-Cyclized Olefins via a Metallocene Catalyst:Polymerization Behavior and Thermal Properties of Copolymers
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作者 Changjiang Wu Minqiao Ren +5 位作者 Liping Hou Shuzhang Qu Xinwei Li Cui Zheng Jian Chen Wei Wang 《Engineering》 SCIE EI CAS CSCD 2023年第11期93-99,共7页
Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a ... Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a few linear a-olefins(e.g.,1-butene,1-hexene,and 1-octene)are used as comonomers in solution polymerization in industry.However,a-olefin comonomers with other structures may have different effects on polymerization in comparison with common linear ones.Moreover,the properties of the corresponding materials may differ significantly.In this work,copolymers of ethylene with linear and endcyclized a-olefins are synthesized using a metallocene catalyst.The copolymerization of ethylene with linear a-olefins results in a higher turn-over frequency(TOF)and lower incorporation than copolymerization with end-cyclized a-olefins,which may indicate that end-cyclized a-olefins have a higher coordination probability and lower insertion rate.In this reaction,the comonomer is distributed randomly in the polymer chain and efficiently destroys crystallization.End-cyclized a-olefins exhibit a much stronger crystallization destructive capacity(CDC)in the copolymer than linear a-olefins,possibly because linear a-olefins act mainly in the radial direction of the main chain of the polymer,while end-cyclized a-olefins act mainly in the axial direction of the main chain. 展开更多
关键词 Metallocene catalyst Ethylene copolymerization Comonomer distribution Crystallization destructive capacity
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Highly efficient organic solar cells with improved stability enabled by ternary copolymers with antioxidant side chains
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作者 Ao Song Qiri Huang +5 位作者 Chunyang Zhang Haoran Tang Kai Zhang Chunchen Liu Fei Huang Yong Cao 《Journal of Semiconductors》 EI CAS CSCD 2023年第8期48-56,共9页
The stability of organic solar cells(OSCs)remains a major concern for their ultimate industrialization due to the photo,oxygen,and water susceptibility of organic photoactive materials.Usually,antioxidant additives ar... The stability of organic solar cells(OSCs)remains a major concern for their ultimate industrialization due to the photo,oxygen,and water susceptibility of organic photoactive materials.Usually,antioxidant additives are blended as radical scavengers into the active layer.However,it will induce the intrinsic morphology instability and adversely affect the efficiency and long-term stability.Herein,the antioxidant dibutylhydroxytoluene(BHT)group has been covalently linked onto the side chain of benzothiadiazole(BT)unit,and a series of ternary copolymers D18-Cl-BTBHTx(x=0,0.05,0.1,0.2)with varied ratio of BHT-containing side chains have been synthesized.It was found that the introduction of BHT side chains would have a negligible effect on the photophysical properties and electronic levels,and the D18-Cl-BTBHT0.05:Y6-based OSC achieved the highest power conversion efficiency(PCE)of 17.6%,which is higher than those based active layer blended with BHT additives.More importantly,the unencapsulated device based on D18-Cl-BTBHTx(x=0.05,0.1,0.2)retained approximately 50%of the initial PCE over 30 hours operation under ambient conditions,significantly outperforming the control device based on D18-Cl(90%degradation in PCE after 30 h).This work provides a new structural design strategy of copolymers for OSCs with simultaneously improved efficiency and stability. 展开更多
关键词 organic solar cells ternary copolymers antioxidant side chain PHOTOSTABILITY
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QUANTITATIVE EVALUATION OF ARRANGEMENT OF MONOMERS IN LINEAR BINARY COPOLYMERS USING A MONTE CARLO SIMULATION METHOD
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作者 Mohammad Najafi Mehdi Salami-Kalajahi Vahid Haddadi-Asl 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2009年第2期195-208,共14页
A Monte Carlo method was used to take thorough account of the influences of different reactivity ratios and initial feed compositions on copolymer microstructure.The model proves the lack of azeotropic behavior in sys... A Monte Carlo method was used to take thorough account of the influences of different reactivity ratios and initial feed compositions on copolymer microstructure.The model proves the lack of azeotropic behavior in systems in which r_A>1 and r_B<1 or vice versa;it is also able to calculate the drift in the copolymer properties:copolymer composition,and randomness parameter.Moreover,for each reactivity ratio pair given,there is a unique reaction conversion,at which macromolecules produced inherit their ... 展开更多
关键词 Radical copolymerization copolymer microstructure copolymer composition Monte Carlo simulation Randomness parameter copolymer heterogeneity Azeotrope point.
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Pyrolysis-Gas Chromatography/Mass Spectrometry for Microstructure and Pyrolysis Pathway of Polyester-Polyether Multiblock Copolymer
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作者 罗爱芹 叶玲 +2 位作者 傅若农 谢桂阳 王显伦 《Journal of Beijing Institute of Technology》 EI CAS 2001年第1期45-50,共6页
The composition and sequence distribution of monomeric units in polyester polyether multiblock copolymer were studied by pyrolysis? gas chromatography (PGC) and pyrolysis gas chromatography/mass spectrometry (PGC/M... The composition and sequence distribution of monomeric units in polyester polyether multiblock copolymer were studied by pyrolysis? gas chromatography (PGC) and pyrolysis gas chromatography/mass spectrometry (PGC/MS). PGC was applied to study the F t curve of the multiblock copolymer and PGC/MS was used to separate and identify the pyrolyzates. DTA experiment was used to study the decomposition temperature. The results show that the beginning point of elastomer’s decomposition was about 300?℃ and the decomposition temperature of most of the sample was 550?℃. Many pyrolyzates were produced because of the breaking of weak bonds in the sample. The possible microstructure was verified and the pyrolysis pathway of the copolymer was investigated. 展开更多
关键词 thermoplastic elastomer polyester polyether multiblock copolymer pyrolysis gas chromatography/mass spectrometry copolymer pyrolysis pathway MICROSTRUCTURE pyrolyzates
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MOLECULAR DESIGN SYNTHESIS AND PROPERTIES OF SIX KINDS OF MULTIPHASE (STYRENE-ETHYLENE OXIDE)COPOLYMERS
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作者 谢洪泉 周培光 +3 位作者 孙文博 夏俊 刘锦 谢东 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1991年第1期1-13,共13页
Multiphase copolymers of styrene (S) and ethylene oxide (EO) are amphiphilic, because of the hydrophobic and amorphous polystyrene (PS) segments and the hydrophilic and crystalline polyoxyethylene (PEO). They have man... Multiphase copolymers of styrene (S) and ethylene oxide (EO) are amphiphilic, because of the hydrophobic and amorphous polystyrene (PS) segments and the hydrophilic and crystalline polyoxyethylene (PEO). They have many uses including polymeric surfactants, electrostatic charge reducers, compatibilizer in polymer 展开更多
关键词 Multiphase polymers Amphiphilic copolymers Graft copolymers Block copolymers Macromolecular design.
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Removal of manganese from waste water by complexation-ultrafiltration using copolymer of maleic acid and acrylic acid 被引量:2
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作者 邱运仁 毛廉君 王伟华 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第4期1196-1201,共6页
Copolymer of maleic acid and acrylic acid (PMA-100), combining with polyvinyl butyral (PVB) ultrafiltration membrane was used for the removal of Mn(II) from waste water by complexation-ultrafiltration. The carbo... Copolymer of maleic acid and acrylic acid (PMA-100), combining with polyvinyl butyral (PVB) ultrafiltration membrane was used for the removal of Mn(II) from waste water by complexation-ultrafiltration. The carboxylic group content of PMA-100 and the rate of complexation reaction were measured. Effects of the mass ratio of PMA-100 to Mn(II) (n), pH, background electrolyte, etc on the rejection rate (R) and permeate flux (J) were investigated. The results show that carboxylic group content of PMA-100 is 9.5 mmol/g. The complexation of Mn(II) with PMA-100 is rapid and completed within 5 min at pH 6.0. Both R and J increase with pH increasing in the range of 2.5-7.0, and R increases with the increase of n at pH 6.0 while J is little affected. The background electrolyte leads to the decrease of R, and CaCl2 has much greater effect on R than NaCl at the same ionic strength. 展开更多
关键词 complexation-ultrafitration copolymer of maleic acid and acrylic acid poly (vinyl butyral) hollow fiber membrane MANGANESE wastewater treatment
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Degradation of PBS-Based Copolymers and Impacts on the Growth of Winter Wheat 被引量:1
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作者 张敏 邢永雷 +2 位作者 苏康宇 马永清 宋吉青 《Agricultural Science & Technology》 CAS 2011年第9期1362-1366,1387,共6页
[Objective] The degradation properties of PBS-based copolymers and impacts on the growth of winter wheat were studied.[Method] Seeds of winter wheat were sown and cultivated in soil,and mixed with equal amounts of PBS... [Objective] The degradation properties of PBS-based copolymers and impacts on the growth of winter wheat were studied.[Method] Seeds of winter wheat were sown and cultivated in soil,and mixed with equal amounts of PBS,PBS-co-HS and PBS-co-BA,to investigate the degradation of polymers in soil and effects of the degradation intermediates and degradation products on seed germination and the growth of winter wheat during the continuous process of degradation.[Result] The results showed that the copolymers had better biodegradation properties than PBS in Lou Soil in Shaanxi Province under the same condition;polymer treatments had not affected the germination percentage and plant height of the winter wheat but contributed to the improvement of plant biomass.[Conclusion] These results suggested that the degradation and degradation products of PBS,PBS-co-HS and PBS-co-BA had not affected the growth of plants in soil environment for temporary. 展开更多
关键词 Winter wheat DEGRADATION PBS-based copolymer
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Synthesis of an Amphiphilic Dendrimer-Like Block Copolymer and Its Application on Drug Delivery
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作者 王帅鹏 宋晓婉 +4 位作者 冯晓双 陈鹏 钱家盛 夏茹 苗继斌 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第5期587-592,I0004,共7页
Dendrimer-like amphiphilic copolymer is a kind of three-dimensional spherical structure polymer. An amphiphilic dendrimer-like diblock copolymer, PEEGE-G2-b-PEO(OH)12, constituted of a hydrophobic poly(ethoxyethyl ... Dendrimer-like amphiphilic copolymer is a kind of three-dimensional spherical structure polymer. An amphiphilic dendrimer-like diblock copolymer, PEEGE-G2-b-PEO(OH)12, constituted of a hydrophobic poly(ethoxyethyl glycidol ether) inner core and a hydrophilic poly(ethylene oxide) outer layer, has been successfully synthesized by the living anionic ring-opening polymerization method. The intermediates and targeted products were charac-terized with 1H NMR spectroscopy and gel permeation chromatography. The application on drug delivery of dendrimer-like diblock copolymer PEEGE-G2-b-PEO(OH)12 using DOX as a model drug was also studied. The drug loading content and encapsulation e ciency were found at 13.07% and 45.75%, respectively. In vitro release experiment results indicated that the drug-loaded micelles exhibited a sustained release behavior under acidic media. 展开更多
关键词 Anionic ring opening polymerization Living polyinerization Dendrimer-likecopolymer Amphiphilic diblock copolymer Drug delivery
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Synthesis and application of lignin-based copolymer LSAA on controlling non-point source pollution resulted from surface runoff 被引量:8
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作者 LIU Chen WU Guangxia MU Huanzhen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第7期820-826,共7页
In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safe... In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safety were studied.The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants.The runoff quantity was decreased by 16.67%-47.00%and the loads of total suspended solids (TSS),chemical oxygen demand (COD),total nit... 展开更多
关键词 application copolymer a copolymer of lignin STARCH acrylamide and acrylic acid (LSAA) non-point source pollution (NPS) surface runoff
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NONBRIDGED HALF-TITANOCENES CONTAINING ANIONIC ANCILLARY DONOR LIGANDS:PROMISING NEW CATALYSTS FOR PRECISE SYNTHESIS OF CYCLIC OLEFIN COPOLYMERS(COCs) 被引量:1
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作者 Kotohiro Nomura 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2008年第5期513-523,共11页
Precise,efficient copolymerizations of ethylene with cyclic olefins[norbornene(NBE),cyclopentene(CPE)]using nonbridged half-titanocenes of type,Cp TiCl_2(L)(Cp =cyclopentadienyl group,L=aryloxo,ketimide)-MAO catalyst ... Precise,efficient copolymerizations of ethylene with cyclic olefins[norbornene(NBE),cyclopentene(CPE)]using nonbridged half-titanocenes of type,Cp TiCl_2(L)(Cp =cyclopentadienyl group,L=aryloxo,ketimide)-MAO catalyst systems have been summarized.CpTiCl_2(N=C Bu_2)exhibited both remarkable catalytic activity and efficient NBE incorporation for ethylene/NBE copolymerization:the NBE incorporation by Cp TiCl_2(X)(X=N=C Bu_2,O-2,6- Pr_2C_6H_3; Cp =Cp,C_5Me_5,indenyl)was related to the calculated coordination ene... 展开更多
关键词 TITANIUM Cyclic olefin copolymers copolymerIZATION ETHYLENE Homogeneous catalysts
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Phase Partition of Acrylonitrile(AN)in Vinylidene Chloride(VDC)/Water System and Its Effect on VDC-AN Copolymer Composition 被引量:1
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作者 周树学 翁志学 +1 位作者 黄志明 潘祖仁 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1999年第4期326-331,共6页
Phase partition of acrylonitrile in the vinylidene chloride/water system at different temperature and under pressure was studied. A calculation method for average VDC-AN copolymer composition with AN phase partition c... Phase partition of acrylonitrile in the vinylidene chloride/water system at different temperature and under pressure was studied. A calculation method for average VDC-AN copolymer composition with AN phase partition considered was proposed. The calculated results are in good agreement with the experimental data nearly the entire conversion range. VDC-AN copolymer with narrower composition distribution can be prepared in the suspension process and interpreted with dynamic equilibrium of AN between the oil and water phases continuously. 展开更多
关键词 vinylidene chloride ACRYLONITRILE suspension copolymerization phase partition copolymer composition
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