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China CDC weekly 2022年第12期4卷 254-258页

作者： Yu Wang Dan Lu Yingying Jin Huanxin Wang Bing Lyu Xin Zhang Ying Huang Gaolin Shu Baiwei Liu Changying Lin Hao Zhao Mingqiang Zhao Lingyu Shen Zhiyong Gao Daitao Zhang Quanyi Wang Mei Qu Lei Jia Beijing Center for Disease Prevention and Control Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food PoisoningBeijingChina Changping District Center for Disease Control and Prevention BeijingChina

Summary What is already known about this topic?Typhoid fever remains a major public health problem in developing *** typhoid fever affects an estimated 27 million people worldwide each *** of indiscriminate antibiotic usage has driven the emergence and spread of multidrug-resistant(MDR)and even extensively drug-resistant(XDR)Salmonella Typhi(***)strains.

关键词： break waterborne XDR

Synthesis of waterborne polyurethane using snow as dispersant:Structures and properties controlled by polyols utilization

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Journal of Materials Science & Technology 2019年第7期35卷 1491-1498页

作者： Changqing Fang Shaofei Pan Zhen Wang Xing Zhou Wanqing Lei Youliang Cheng Faculty of Printing Packaging Engineering and Digital Media TechnologyXi'an University of TechnologyXi'an710048China School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an710048China

waterborne polyurethane (WPU) dispersions have gained attention towards environm entally-friendly synthesis. In this article, a series of waterborne polyurethane em ulsions was successfully synthesized and extensively characterized in terms of thermal, mechanical properties, hydrophilic behavior and morphology. Snowwas chosen as dispersant instead of comm only used water. Preparation param eters such as intrinsic properties and molecular weight of polyols were discussed systematically. A chain structure was confirmed by Fourier transform infrared (FT-IR) spectroscopy. when com paring the nature of the polyols (PPG, PEG and PNA, 2000g/mol) of this study, as-synthesized polyether waterborne polyurethane provided higher solid content, viscosity and water-resistance. However, polyester waterborne polyurethane perform ed differently and it exhibited higher therm al stability and crystallinity. When com paring the samples (WPU-N210, WPU-N220, WPU-N230 and WPU-N240) with different molecular weight of the same polyol (PPG) used as soft segment, the emulsion WPU-N220 with molecular weight of 2000g/mol PPG provided the highest solid content and lowest viscosity. It was observed th at particle size was uniform and highly dispersed for all sam ples from TEM images. Therm ogravim etric, differential scanning calorim etry (DSC) and X-ray diffraction results dem onstrated that the emulsion WPU-N230 with m olecular weight of 3000 g/mol PPG possessed higher therm al stability and crystallinity than the other samples. The reason was that the Tg and thermal stability were increased with increasing molecular weight. when molecular weight increased, the arrangem ent of soft segm ent became more regular and so did the regularity of the molecular chains. This work demonstrated that different polyols as soft segment applied could lead to great differences in the structure and property of the resulting WPU.

关键词： waterborne polyurethane (WPU) Snow Soft segment Polyester Polyether

Corrosion protection of waterborne epoxy coatings containing mussel-inspired adhesive polymers based on polyaspartamide derivatives on carbon steel

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Journal of Materials Science & Technology 2018年第12期34卷 2464-2471页

作者： Mingliang Yang Jianhua Wu Daqing Fang Bo Li Yang Yang College of Materials Science and Chemical Engineering Harbin Engineering UniversityHarbin 150001China State Key Laboratory for Marine Corrosion and Protection Qingdao 266101China Xiamen Sunrui Ship Coating Co. LTD.Xiamen 361101China

A novel mussel-inspired adhesive polymer（PHEA-DOPA） containing the 3,4-dihydroxyphenylalanine（DOPA） functional group based on polyaspartamide derivatives was synthesized. The corrosion protection of the waterborne epoxy coatings containing the adhesive polymers was investigated by electrochemical impedance spectroscopy（EIS）. The results indicated that the PHEA-DOPA could improve the corrosion resistance of the waterborne epoxy coating. The corrosion products were also analyzed by Raman microspectroscopy（RM）, indicating the formation of the insoluble DOPA-Fe complexes on the carbon steel surface. These complexes simultaneously acting as a passivating layer, can inhibit the process of corrosion at the metal-solution interface. The differential scanning calorimeter（DSC） measurement indicated that PHEA-DOPA can increase the crosslinking density of coating. The effect of O;on the protective mechanism of the PHEA-DOPA coating in a 3.5% NaCl solution was also evaluated by EIS. The results indicated that the barrier effect was significantly improved under aerated conditions because DOPA was oxidized to DOPA-quinone（Dq） by O;, which triggered the reaction with Fe ions that were released from the surface of the carbon steel. This led to more compact coatings.

关键词： Corrosion protection Adhesive polymer Inhibitor waterborne PHEA-DOPA

INFLUENCE OF SILOXANE CO-SEGMENT LENGTH AND CONTENT OF waterborne POLYSILOXANE-URETHANE COPOLYMERS ON THEIR WATER RESISTANCE,THERMAL STABILITY AND MECHANICAL PROPERTIES

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Chinese Journal of Polymer Science 2010年第2期28卷 219-229页

作者：郑强 Department of Polymer Science and Engineering Zhejiang University Key Laboratory of Macromolecular Synthesis and Functionalization Ministry of Education

A series of stable waterborne polysiloxaneurethane （WPSUR） dispersions were prepared using amino-terminated polydimethylsiloxane （NS）, dimethylolpropionic acid （DMPA）, castor oil, polypropylene glycol and toluene diisocyanate. Meanwhile, NS with different molecular weights was synthesized and used as the soft co-segment. Effects of types and contents of soft co-segments as well as chain extenders on the thermal degradation and stability for WPSUR films were examined. Results reveal that WPSUR films exhibit excellent water resistance and mechanical properties as compared with pure polyurethane （PU） films, and the NS soft co-segment possesses a remarkable effect on the second stage （stage Ⅱ）, while the content of the hard segment is propitious to the initial stage （stage Ⅰ）. Moreover, the highest temperature of stage Ⅱ （T2m） for WPSUR films using NS as soft co-segment is 413℃, approximately being 30℃ higher than that of those typical PUs using HDA and APDMS as the chain extenders, respectively.

关键词： waterborne Polysiloxane Polyurethane Castor oil Thermal properties Water resistance.

EFFECT OF SILICA NANOPARTICLES ON PROPERTIES OF waterborne POLYURETHANES

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Chinese Journal of Polymer Science 2012年第6期30卷 845-852页

作者：冯利邦 Key Laboratory of Road Bridge and Underground Engineering of Gansu Province Lanzhou Jiaotong University School of Mechatronic Engineering Lanzhou Jiaotong University

waterborne polyurethane composites containing silica nanoparticles are synthesized successfully via the in situ polymerization. The structure, thermal stability, surface hardness, tensile strength, UV-Vis absorbance, dynamic mechanical properties and chemicals resistance of the resulting composites are investigated by FTIR, TEM, TGA, UV-Vis, DMA and chemicals soakage measurements. Results show that polyurethane molecules and silica nanoparticles are linked with covalent bonds. As a result, physical properties of polyurethane composites, such as thermal stability, surface hardness, weather and chemicals resistance are all improved when an appropriate concentration of silica nanoparticles are incorporated.

关键词： Nanosilica waterborne Polyurethanes Property.

Investigation on Viscoelasticity of waterborne Polyurethane with Azobenzene-containing Pendant Groups under Ultraviolet and Visible-light Irradiation

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Chinese Journal of Polymer Science 2019年第12期37卷 1267-1272,I0007页

作者： Yi-Jun Liu Dong Liu Si-Han Li Hua-Qing Liang Fang-Ming Zhu GDHPPC Lab School of ChemistrySun Yat-sen UniversityGuangzhou 510275China Key Lab for Polymer Composite and Functional Materials of Ministry of Education School of ChemistrySun Yat-sen UniversityGuangzhou 510275China

In this study,a novel waterborne polyurethane(WPU)with azobenzene-containing(azo-containing)pendant groups was synthesized by isophorone diisocyanate,long-chain diol of polycaprolactone,2-ethyl-2-methyl-butanoic acid(2,2-dimethylolpropionic acid),10-(4-(phenyldiazenyl)phenoxy)decyl-3-hydroxy-2-(hydroxymethyl)-2-methylpropanoate,and N,N-diethyl-ethanamine(triethylamine).Moreover,the influence of ultraviolet and visible(UV-Vis)light irradiation on the viscoelasticity of azo-containing WPU film in terms of the reversible trans-cis photoisomerization of azo-containing pendant groups was investigated by UV-Vis light spectroscopy,atomic force microscopy,and dynamic thermomechanical *** results revealed that the adhesion of azo-containing WPU with single crystal silicon atomic force microscope probe was about 13 n N when irradiated by 450 nm Vis light for 60 s at 25°***,the adhesion increased to 82 n N after irradiation with 365 nm UV light for 60 s at 25°*** addition,the azo-containing WPU presented a photo-induced reversible transition of tensile modulus and tanδin the range from about 2 MPa to 22 MPa and 6000 to 0.35 with UV-Vis light cyclic irradiation for 120 s at 25°C,respectively.

关键词： waterborne polyurethane Viscoelasticity Photoisomerization Azobenzene

Cure Behaviors and Water Up-take Evaluation of a New waterborne Epoxy Resin

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Journal of Wuhan University of Technology(Materials Science) 2012年第3期27卷 437-442页

作者：万涛 State Key Lab of Geohazard Prevention & Geoenvironment Protection Chengdu University of Technology College of Materials and Chemistry & Chemical Engineering Chengdu University of Technology

Cure behaviors and water up-take evaluation of a low cost, ecofriendly and water soluble epoxy resin prepared by reaction between epichlorohydrin and PEG400, PEG600 and PEG1000, respectively, were investigated using non-isothermal differential scanning calorimetry （DSC） and gravimetrical method, respectively. Factors affecting the cure behaviors as well as water up-take of waterborne epoxy resins, such as amount of triethylenetetramine （TETA） and triethylene diamine （TEDA）, PEG molecular weight, curing temperature, were systematically investigated. The prepared water soluble epoxy resins can be cured under room temperature with the shape of the curing curves similar to that expected for an autocatalytic reaction.

关键词： cure waterborne epoxy resin water up-take

Mechanical Properties and Morphology of the Clay/waterborne Polyurethane Nanocomposite

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Journal of Wuhan University of Technology(Materials Science) 2006年第4期21卷 24-27页

作者：张永成王心葵 Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan 030001China

Stable clayl waterborne polyurethane nanocompostie dispersions were synthesized by sulfonated poly （ butylene adipate ） diol , 4,4-diphenylmethane diisocyanate , dimethyl propionic acid, 1,4-butanediol, triethyl amine and clay-water dispersion through a route named prepolymer acetone mixing progress. The reinforced mechanical properties and thermal resistance of films casting from h were examined by dynamic mechanical analyses （ DMA ）, thermogravimetrie analyses （ TGA ） and tensile tests. Furthermore, the morphology of these nanocompostie films and dispersions were observed by transmission electron microscopy（TEM）, scanning electron microscopy（SEM）, wide-angle X-ray diffraction analyses（ WXRD ）. The experimental results reveal that the clay could be predominantly dispersed in the pristine polymer forming nanacomposties, and evidently enhanced the tensile properties and modulus of it. Addhionally, the best-reinforced effect could occur when the clay content was near 1 wt% .

关键词： polyurethane waterborne clay nanacornposties

Synthesizing Self-Crosslinking waterborne Polyurethane-Silanol Dispersion for Waterproofing Application

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Open Journal of Organic Polymer Materials 2022年第1期12卷 1-15页

作者： Harsh Pandya Prakash A. Mahanwar Department of Polymer and Surface Engineering Institute of Chemical Technology Mumbai India

Polyurethane dispersions (PUD) have diversified into a myriad of applications over the years. This has led to extensive research on both industrial and laboratory fronts as polyurethane dispersions provide liberty to interplay at the molecular level to diversify the properties of the product which has also led to the development of eco-friendly waterborne dispersions. Yet, waterborne PUDs are limited in their mechanical and physical properties as compared to solvent-based products. The incorporation of crosslinkers in the PUD further bolsters these properties thus improving water and solvent resistance. The incorporation of silanols increases solvent resistance and adhesion of the resultant PUD. In this work, a post crosslinking system based on the ketone-hydrazine mechanism was incorporated into the PUD thus providing the required structural reinforcement for construction application. The targeted application for this work is the use of PUDs for waterproofing.

关键词： Polyurethane Dispersion waterborne Crosslinking Waterproofing

Preparation of Photochromic waterborne Polyurethane Films:Effect of Spiropyran Concentration on Photochromic Properties

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Journal of Donghua University(English Edition) 2020年第1期37卷 28-34页

作者： BAO Lihong WANG Shixian School of Materials Design and Engineering Beijing Institute of Fashion TechnologyBeijing 100029China Beijing Key Laboratory of Clothing Materials R&D and Assessment Beijing 100029China

Incorporation of photochromic compounds to the polymer through chemical bonding will result in an enhancement of photoactivity and stabilization of optical ***,spiropyran(SP)was introduced into polyurethane(PU)through semi-continuous emulsion copolymerization to get waterborne polyurethane dispersion(SPU).Studies on photochromic properties by UV-vis technique demonstrated the absorption intensity increased with the increasing of SP concentration and the colorless film turned to purple under UV *** kinetics for ring-opening and ring-closing reaction against SP were both first order,but the rate constants decreased with the increasing of SP *** prepared SPU films showed reasonable photostability and photoreversibility according to the convenient test methods under UV-vis *** dependence studies demonstrated that the photobleaching rate increased at higher temperatures with the same SP *** chemical combination between SP and isocyanate(NCO)end group of polyurethane was confirmed through swelling *** studies were conducted by scanning electron microscope(SEM)micrographs and showed good compatibility between SP and PU.

关键词： spiropyran concentration waterborne polyurethane film photochromic properties kinetics