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Microstructure and mechanical properties of 3D printed ceramics with different vinyl acetate contents

Rare Metals 2021年第11期40卷 3241-3250页

作者： He Li Yong-Sheng Liu Yan-Song Liu Qing-Feng Zeng Jing-Jing Liang Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China NPU-SAS Joint Research Center of Advanced Ceramics Northwestern Polytechnical UniversityXi’an 710072China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

Stereolithography(SL)-based three-dimensional(3D) printing technique is an efficient method for the fabrication of alumina *** alumina slurry is difficult to obtain due to the barrier between hydrophilic alumina and oleophilic *** not only requires that the ceramic slurry possessed low viscosity and uniformity,but also requires that the slurry could complete the photocuring *** this study,vinyl acetate was added in the ceramic slurry as a bridge to connect alumina and resin,and the effects of vinyl acetate content on the microstructure and mechanical properties of the alumina ceramics were systematically *** results showed that the alumina ceramics were composed of three types of particles which included large aggregates,individual particles,and long-columnshaped *** shrinkage,bulk density,and crystallite size of the ceramics increased with the increase in vinyl acetate *** open porosity decreased with the increase in vinyl acetate *** flexural strength of the ceramics first increased and subsequently decreased with the increase in vinyl acetate *** shrinkage in Z direction was much greater than that in X or Y *** on the above results,the optimum vinyl acetate content for alumina slurry was 10 wt%,which resulted in sintered ceramic with the shrinkage of 15.6% in X direction,13.5% in Ydirection,21.9% in Z direction,bulk density of 1.9 g·cm^(-3),open porosity of 50.1%,and flexural strength of 24.4 *** sintered ceramics satisfy the requirement of alumina ceramic cores.

关键词： Stereolithography Alumina ceramics vinyl acetate Microstructure Mechanical properties

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PHOTOCOPOLYMERIZATION OF MALEIC ANHYDRIDE AND vinyl acetate

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Chinese Journal of Polymer Science 1990年第3期8卷 261-268页

作者：李小放李善君秦安慰于同隐 Department of Chemistry Shandong University Jinan China Department of Materials Science Fudan University Shanghai

The charge-transfer complex of maleic anhydride and vinyl acetate was copolymerized under UV light. The chain composition and structure of the copolymer were analyzed with conductometry and NMR, and the chain sequence was determined as alternating. The copolymerization rates at different feed ratios, temperatures and in different solvents were investigated, giving evidence to the very active involvement of the CT complexes in the copolymerization. Terpolymerization with acrylonitrile also showed that the complex mechanism was a proper one for this system.

关键词： Maleic anhydride vinyl acetate Charge-transfer complex Photocopolymerization Terpolymer

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STUDIES OF THE CRYSTALLIZATION BEHAVIOR IN THE CRYSTALLINE/AMORPHOUS POLYMER BLENDS: POLY(ETHYLENE OXIDE)/POLY(METHYL METHACRYLATE) AND POLY(ETHYLENE OXIDE)/POLY(vinyl acetate)

引用

Chinese Journal of Polymer Science 1985年第3期3卷 280-288页

作者：李玄王盈康杨扬 Institute of Chemistry Academia Sinica Beijing Chemistry Department Peking University

The crystallization process of poly(ethylene oxide) (PEO)/poly(methyl methacrylate) (PMMA)and PEO/poly(vinyl acetate) (PVAc) blends has been characterized by Fourier Transform Infrared(FTIR) spectra in conjunction with Differential Scanning Calorimeter (DSC) measurements. Thecrystallinity of PEO varies consistently with PEO content in PEO/PVAc blends and the PEO/PMMAblends containing 50 wt% or less PMMA. For the PEO/PMMA blends containing 60 wt% ormore PMMA, the crystallinity of PEO decreases more than PEO content but develops with crystal-lization time. These results can be explained in terms of difference between the crystallization tem-perature (T_c) and glass transition temperature (T_g) of the blends as a function of content of amorphouscomponent.

关键词： PEO METHYL METHACRYLATE POLY STUDIES OF THE CRYSTALLIZATION BEHAVIOR IN THE CRYSTALLINE/AMORPHOUS POLYMER BLENDS vinyl acetate AND POLY ETHYLENE OXIDE PMMA

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RADIATION CROSSLINKING OF BRANCHED POLY (vinyl acetate)

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Chinese Journal of Polymer Science 1985年第4期3卷 362-366页

作者：张万喜庄国庆孙家珍 Changchun Institute of Applied Chemistry Academia Sinica Changchun

In the present work, radiation crosslinking of different branched poly （vinyl acetate） have beemstudied and the validity of the relationship between sol fraction and radiation dose: R(S+S1/2=1/U1qo+p′o/qoRβto bran... 详细信息

关键词： vinyl acetate RADIATION CROSSLINKING OF BRANCHED POLY

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STUDIES ON ULTRASONIC GRAFTING OF POLY(vinyl acetate) WITH POLY(ETHYLENE OXIDE)

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Chinese Journal of Polymer Science 1983年第1期 60-69页

作者：李文端徐僖 Polymer Research Institute Chengdu University of Science and Technology Chengdu

The ultrasonic degradation of poly（ethylene oxide） and poly（vinyl acetate） in benzene solution, and grafting reaction of poly（vinyl acetate） with poly（ethylene oxide） were studied. It is found that the chain-scission reactions follow the course suggested by D. W. Ovenall. The structure of the copolymer was identified by IR, NMR and DTA, showing that the copolymer prepared is a graft copolymer mainly. The copolymer formed by irradiating 1% PEO/PVAc solution （PEO/PVAc:1/1 by weight） for a period of 10 rain at 18.2 kHZ, with 2.0 A input current on reversed main circuit, amounts to 10.5%.

关键词： PEO vinyl acetate WITH POLY ETHYLENE OXIDE STUDIES ON ULTRASONIC GRAFTING OF POLY

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Polyurethane Hybrid-Based Wood Adhesive: Review

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Open Journal of Polymer Chemistry 2024年第1期14卷 41-62页

作者： Rahul Khandagale Sainath Gadhave Ravindra V. Gadhave Super Bond Adhesives Private Limited Thane India

Based on commercially available polyvinyl alcohol (PVA) stabilised polyvinyl acetate (PVAc), emulsion adhesives are neither heat nor moisture-resistant and show weak strength at high relative humidity and high temperatures. Pre- or post-crosslinking is another method used to manufacture a conventional vinyl-based homopolymers or copolymers system with improved water resistance. vinyl neodecanoate (VeoVa), N-methylolacrylamide (NMA), Methacrylamide, methacrylic acid (MAA), and other self-crosslinking comonomers are typically inserted to produce highly water-resistant vinyl based homopolymers or copolymers. Additionally, organic crosslinkers like glyoxal, glutaraldehyde, citric acid, tartaric acid, and the like, as well as inorganic crosslinkers like acidic metal salts like aluminium chloride, aluminium nitrate, boric acid, and the like, can be used to prepare the highly water-resistant vinyl based homopolymers or copolymers. It is also possible to combine the self-crosslinking comonomers with the organic crosslinkers. Recently, a different hybrid chemistry has been developed that improves lap shear strength, has outstanding water resistance, good durability, and doesn’t require any additional crosslinker agents. Two distinct polymers were combined to develop hybrid polymers. They usually involve mixing an organic polymer with a polymer. There are many capping agents that are used for polyurethanes to produce acrylics that are capped with polyurethane and used as an oligomer in PVAc wood glue. Here, in this paper, we reviewed the different hybrid chemistry based on polyurethane chemistry for wood bonding applications.

关键词： vinyl acetate Hybrid Polyurethane Wood Adhesive

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CHEMICAL MODIFICATION OF THE SURFACE OF CALCIUM ALGINATE GEL BEADS

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Chinese Journal of Polymer Science 2004年第2期22卷 183-186页

作者：萧聪明 College of Materials Science and Engineering Huaqiao University Quanzhou 362011 China

The chemical modification of the surface of calcium alginate gel beads (CAGB) via grafting copolymerization with vinyl acetate (VAc) was studied. The optimum reaction conditions with activation and graft copolymerization two steps were explored. First, 5 grams CAGB with 2.5 mm initial diameter was initiated with 0.0493 mol/L K2S2O8 at 51 °C for 30 min in 15 mL 1 % PVA/H2O. Then 4.34 moi/L VAc was added dropwise and the reaction was allowed to proce at 48 °C for 3 h. The grafting efficiency could come up to 30%. It was found the stability of modified CAGB in the air and in electrolyte solutions was greatly improved.

关键词： Calcium alginate gel bead vinyl acetate Graft copolymerization Chemical modification

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N-Heterocyclic carbene-catalyzed synthesis of acetyltributylcitrate via a transesterification reaction

引用

Chinese Chemical Letters 2014年第2期25卷 215-217页

作者： Lin He Hao Guo Xiao-Wei Ma Jie Zhang Cheng-Zhi Gu Wei Wang Bin Dai Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan and School of Chemistry and Chemical Engineering Shihezi University

A new methodology for the synthesis of a green plasticizer acetyltributylcitrate through a transesterification reaction was developed. Under the catalysis of alkyl-substituted imidazol-type N-heterocyclic carbenes, tr... 详细信息

关键词： Acetyltributylcitrate N-Heterocyclic carbenes Transesterification reaction Tributyl citrate vinyl acetate

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Preparation of(R)-2-chloro-1-(m-chlorophenyl)ethanol by Lipozyme TL IM-catalyzed second resolution

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Chinese Chemical Letters 2012年第3期23卷 289-292页

作者： Shi Wen Xia Hui Lin Yong Zheng Chen College of Bio-information Chongqing University of Posts and TelecommunicationsChongqing 400065China Chengdu Institute of Biology Chinese Academy of SciencesChengdu 610041China Department of Pharmacy Zunyi Medical CollegeZunyi 563003China

（R）-2-Chloro-l-（m-chlorophenyl）ethanol,a precursor of（R）-3-chlorostyrene oxide which is the key chiral intermediate for the preparation of severalβ3-adrenergic receptor agonists was prepared in 40%yield and 99%... 详细信息

关键词： (R)-2-Chloro-1-(m-chlorophenyl)ethanol LipozymeTL IM Enzymatic transesterification vinyl acetate Second resolution

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Acylation of Quercetin with a Novel Thermophilic Esterase as Biocatalyst

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Chemical Research in Chinese Universities 2012年第2期28卷 225-229页

作者： XIE Xiao-na ZHANG Chun-li XUN Er-na WANG Jia-xin ZHANG Hong WANG Lei WANG Zhi The First Hospital of Jilin University Changchun 130021P.R.China Key Laboratory for Molecular Enzymology and Engineering Ministry of Education College of Physical Education Jilin UniversityChangehun 130012P.R.China

The regioselective acylation of quercetin catalyzed by a novel thermophilic esterase（APE1547） from the archaeon Aeropyrum pernix K1 was successfully conducted in organic *** effects of acyl donor,substrate ratio,organic solvent,temperature,and water activity were *** the optimum conditions,a yield of 74% for its mono ester could be achieved in the reaction for about 6 *** the reaction time extending to about 30 h,the final conversion of quercetin was about 100% and three products were synthesized.

关键词： Quercetin vinyl acetate APE1547 Acylation

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