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Sample records for acrylic acid esters

  1. Acrylic Acid and Esters Will Be Oversupply

    Institute of Scientific and Technical Information of China (English)

    Zheng Chengwang

    2007-01-01

    @@ Drastic capacity growth The production capacity of acrylic acid in China has grown drastically in recent years. With the completion of the 80 thousand t/a acrylic acid and 130 thous and t/a acrylic ester project in Shenyang Paraffin Chemical Industrial Co., Ltd., (CCR2006,No. 31) the capacity of acrylic acid in China has reached 882 thousand t/a.

  2. Rare linking hydrogels based on acrylic acid and carbohydrate esters

    Directory of Open Access Journals (Sweden)

    U. Akhmedov

    2012-09-01

    Full Text Available The process of copolymerization of acrylic acid and esters poliallil sucrose; pentaerythritol and sorbitol, some of its laws are identified. The kinetic regularities of copolymerization and the optimum conditions of synthesis was established.

  3. Scientific Opinion on the safety evaluation of the active substance, acrylic acid, sodium salt, co-polymer with acrylic acid, methyl ester, methacrylic acid, 2 hydroxypropylester, and acrylic acid cross-linked for use in active food contact materials

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2013-04-01

    Full Text Available This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety evaluation of the acrylic acid, sodium salt, co-polymer with acrylic acid, methyl ester, methacrylic acid, 2 hydroxypropylester, and acrylic acid cross-linked (CAS No. 117675-55-5, FCM Substance No 1022, to be used as liquid absorber in the form of fibres in absorbent pads for the packaging of fresh or frozen meat, poultry, and fish as well as fresh fruits and vegetables. The Panel considered that migration is not expected when the absorption capacity of the pads is not exceeded. Therefore no exposure from the consumption of the packed food is expected. The Panel also considered that none of these starting substances and the cross-linked polymer gives rise to concern for genotoxicity. Therefore the CEF Panel concluded that the use of the substance acrylic acid, sodium salt, co-polymer with acrylic acid, methyl ester, methacrylic acid, 2 hydroxypropylester, and acrylic acid cross-linked does not raise a safety concern when used as fibres in absorber pads for the packaging of fresh or frozen meat, poultry, fish, fruits and vegetables under conditions under which the absorption capacity of the pads is not exceeded and mechanical release of the fibres from the pads is excluded.

  4. Preparation and Characterization of Ester from Rosin Acrylic Acid Adduct and Hydroxyethyl Methacrylate

    Institute of Scientific and Technical Information of China (English)

    C.L.Yu; F.A.Zhang

    2007-01-01

    1 Results Rosin is a sort of important renewable resources,which is a foremost product of our country forestry. It has very important meaning to modify the rosin based on its molecule structure and active group, to develop some deep processing products, and to endure with rosin new characteristic[1]. This work uses the rosin and acrylic acid to form rosin adduct, and then reacted with 2-hydroxyethyl methacrylate (HEMA) to form ester under the different condition. The effect of different ratios with the ...

  5. 40 CFR 721.2805 - Acrylate ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under...

  6. Rapid Output Growth of Special Acrylic Esters

    Institute of Scientific and Technical Information of China (English)

    Wang Lianzhi

    2007-01-01

    @@ Acrylic esters are usually classified into general-purpose varieties and special varieties. The production and application of general-purpose varieties is already quite matured in the world and their output growth tends to be flat. Owing to the development of coatings, electronics, automobiles,textiles, printing and construction sectors, especially the application of radiation curing technology in various sectors, special acrylic esters have developed rapidly.

  7. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated benzyl ester acrylate... Specific Chemical Substances § 721.329 Halogenated benzyl ester acrylate (generic). (a) Chemical substance... halogenated benzyl ester acrylate (PMN P-90-1527) is subject to reporting under this section for...

  8. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Trifunctional acrylic ester (generic... Specific Chemical Substances § 721.10180 Trifunctional acrylic ester (generic). (a) Chemical substance and... acrylic ester (PMN P-04-692) is subject to reporting under this section for the significant new...

  9. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section... COATINGS Substances for Use as Components of Coatings § 175.210 Acrylate ester copolymer coating. Acrylate ester copolymer coating may safely be used as a food-contact surface of articles intended for...

  10. Synthesis of comb type and semi-interpenetrating networks of acryloyl-L-proline methyl ester and poly (acrylic acid) for Cu (II) immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Giovanni [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, A. Postal 70-543, 04510 Mexico, D.F. (Mexico); Burillo, Guillermina, E-mail: burillo@nucleares.unam.m [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, A. Postal 70-543, 04510 Mexico, D.F. (Mexico)

    2010-08-15

    Graft copolymer hydrogels and semi-interpenetrating networks (s-IPN) of acryloyl-L-proline methyl ester (A-ProOMe) and poly (acrylic acid) (PAAc) were synthesized in methanol solutions, by ionizing radiation (gamma rays from a Co{sup 60} source at room temperature). These systems are thermo and pH-sensitive and the pH sensitivity increases from acidic to basic solutions. The Lower Critical Solution Temperature (LCST), due to presence of poly (acryloyl-L-proline methyl ester) (PA-ProOMe) has been found between 18 and 20 deg. C and an unexpected Upper Critical Solution Temperature (UCST) due to poly acrylic acid (PAAc) has been found between 21 and 22 deg. C. Preliminary studies on the immobilization of Cu{sup 2+} for both hydrogels were done at several pH values at room temperature. Other techniques employed to characterize the comb type hydrogels and sIPN included scanning electronic microscopy (SEM) and infrared (FTIR-ATR).

  11. Time-resolved EPR investigation of potential model systems for acrylate polymer main chain radicals based on esters of Kemp's tri-acid.

    Science.gov (United States)

    Lebedeva, Natalia V; Gorelik, Elena V; Magnus-Aryitey, Damaris; Hill, Terence E; Forbes, Malcolm D E

    2009-05-14

    Methyl esters of Kemp's tri-acid and cyclohexanetricarboxylic acid are structurally similar to acrylate polymers, having the same functionalities and stereoregularities as poly(methylmethacrylate) and poly(methylacrylate), respectively. The photochemistry and free radicals from these model systems have been studied using time-resolved electron paramagnetic resonance spectroscopy with laser flash photolysis at 248 nm. Chemically induced electron spin polarization from the triplet mechanism (net emission) is observed. Well-resolved spectra are obtained at all temperatures for the model system radicals, which are determined to be in the slow motion condition, that is, there is no interconversion of chair conformations. The temperature dependence of the spectra is minimal; some hyperfine lines shift as the temperature increases, but without much broadening. Density functional theory calculations are presented and discussed in support of the experimental data.

  12. Synthesis and Application of a New Acrylic Ester Resin for Recycling SIPA from its Water Solution

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new acrylic ester polymer YWB-7 resin was prepared and characterized. The properties of YWB-7 resin were compared with those of the commercial Amberlite XAD-7, Diaion HP2MG and hypercrosslinked macroporous polymer NDA-150 resins. Both surface area and micropore area of YWB-7 resin were bigger than those of XAD-7 resin and HP2MG resin. The YWB-7 resin was successfully employed to recycle 5-sodiosulfoisophthalic acids (SIPA) from its solutions with and without methanol.

  13. Antimicrobial activity of poly(acrylic acid) block copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Gratzl, Günther, E-mail: guenther.gratzl@jku.at [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Paulik, Christian [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Hild, Sabine [Johannes Kepler University Linz, Institute of Polymer Science, Altenberger Str. 69, 4040 Linz (Austria); Guggenbichler, Josef P.; Lackner, Maximilian [AMiSTec GmbH and Co. KG, Leitweg 13, 6345 Kössen, Tirol (Austria)

    2014-05-01

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed.

  14. Constrained photophysics of partially and fully encapsulated charge transfer probe (E)-3-(4-Methylaminophenyl) acrylic acid methyl ester inside cyclodextrin nano-cavities: Evidence of cyclodextrins cavity dependent complex stoichiometry

    Science.gov (United States)

    Ghosh, Shalini; Jana, Sankar; Guchhait, Nikhil

    2011-12-01

    The polarity sensitive intra-molecular charge transfer (ICT) emission from (E)-3-(4-Methylaminophenyl) acrylic acid methyl ester (MAPAME) is found to show distinct changes once introduced into the nano-cavities of cyclodextrins in aqueous environment. Movement of the molecule from the more polar aqueous environment to the less polar, hydrophobic cyclodextrin interior is marked by the blue shift of the CT emission band with simultaneous fluorescence intensity enhancement. The emission spectral changes on complexation with the α- and β-CD show different stoichiometries as observed from the Benesi-Hildebrand plots. Fluorescence anisotropy and lifetime measurements were performed to probe the different behaviors of MAPAME in aqueous α- and β-CD solutions.

  15. SYNTHESIS OF ACRYLIC ESTERS IN PHASE TRANSFER CATALYSIS: KINETICS AND ECOLOGICAL ASPECTS

    Directory of Open Access Journals (Sweden)

    GAGIK TOROSYAN

    2012-06-01

    Full Text Available Phase-Transfer Catalysis (PTC technology is used in the commercial manufacture and also in pollution mitigation treatment processes. In the paper is demonstrated the synthesis of esters of acrylic and metacrylic acids, which have wide applications in the industry for the synthesis of unique polymeric materials, by phase transfer catalysis method. It is necessary to notice that the synthesis of acrylic acids in PTC medium is more important because that compounds are more sensitive at acidic and basic conditions. Here is shown that the offered method has more advantages in comparison with the traditional methods. PTC is characterized by a higher degree of conversion of raw materials into useful products, smaller material and power resources consumption. The offered method for acrylic ester synthesis in comparison with the traditional methods has more advantages: higher process rates, mild reaction conditions, allowing lower energy costs, the complete elimination of hazardous and dangerous organic solvents, all leading to a sharp reduction of air pollution, and volume of generated wastewaters.

  16. Synthesis and application in acrylic rubber of 2-butoxyethanol esters of hexanedioic acid%己二酸-乙二醇单丁醚酯的合成及在丙烯酸酯橡胶中的应用

    Institute of Scientific and Technical Information of China (English)

    宋林勇; 贺楠楠; 周艺峰; 聂王焰

    2011-01-01

    用对甲苯磺酸作催化剂,以己二酸与乙二醇单丁醚为原料,通过酯化反应合成了己二酸-乙二醇单丁醚酯增塑剂,考察了反应时间、醇酸摩尔比及催化剂和带水剂甲苯的用量对酯化反应的影响,通过傅里叶变换红外光谱及核磁共振氢谱对产物进行了表征,并研究了该增塑剂在丙烯酸酯橡胶中的高低温增塑性能.结果表明,酯化反应的最佳反应条件为反应时间180 min、醇酸摩尔比2.5、催化剂和带水剂的质量分数分别是醇与酸总用量的0.5%和30%;添加10份该增塑剂可使丙烯酸酯橡胶的脆化温度达到-35.0℃,且在150℃下能保持较好的物理机械性能.%Plasticizer, 2-butoxyethanol ester of hexanedioic acid, was synthesized by esterification of hexanedioic acid and 2-butoxyethanol with toluene sulfonic acid as catalyst, the effects of reaction time ,mole ratio of alcohol to acid and level of catalyst and water-carrying agent toluene on the esterification were investigated, the synthesized products was characterized by Fourier transform-infrared spectroscopy and proton nuclear magnetic resonance spectroscopy, and the high and low temperature plasticizing ability was studied in detail. The results showed that the optimal condition for esterification was as follows : reaction time 180 min , mole ratio of alcohol to acid 2. 5, mass fraction of catalyst and water-carrying agent in total amount of alcohol and acid 0. 5% and 30% respectively. The brittlness temperature of acrylic rubber could reach -35℃ when the amount of the plasticizer was 10 phr, and the mechanical property was kept well at 150 ℃ .

  17. 活性炭强化臭氧氧化丙烯酸及酯废水的研究%Study on the activated carbon enhanced process of ozone oxidation acrylic acid and ester wastewater

    Institute of Scientific and Technical Information of China (English)

    李立峰; 顾锡慧; 滕厚开; 张艳芳; 陈军

    2014-01-01

    The COD of bio-chemically treated acrylic acid and ester wastewater is 550 mg/L. It is necessary for the wastewater to have advanced treatment,so as to reach the discharge standard. The treatment efficiency of activated carbon enhanced ozone oxidation process used for the wastewater has been studied. The effects of wastewater alka-linity,activated carbon filling height,concentration of ozone and wastewater extra column circulating flow rate on the COD removing rate are investigated. The experimental results show that,under optimal condition,the reaction goes on for two hours,the wastewater COD can be reduced to 35 mg/L,meeting the first class requirements of the Inte-grated Wastewater Discharge Standard(GB 8978—1996).%生化后的丙烯酸及酯废水COD为550 mg/L,需进行深度处理才能达标排放。研究了活性炭强化的臭氧氧化工艺对该废水的处理效能,考察了废水碱度、活性炭装填高度、臭氧浓度和废水柱外循环流量对COD去除率的影响。实验结果表明,在最佳条件下反应2 h,废水COD可降至35 mg/L,达到《污水综合排放标准》(GB 8978—1996)中的一级标准要求。

  18. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid...

  19. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  20. Investigation of Acrylic Acid at High Pressure using Neutron Diffraction

    DEFF Research Database (Denmark)

    Johnston, Blair F.; Marshall, William G.; Parsons, Simon

    2014-01-01

    This article details the exploration of perdeuterated acrylic acid at high pressure using neutron diffraction. The structural changes that occur in acrylic acid-d4 are followed via diffraction and rationalised using the Pixel method. Acrylic acid undergoes a reconstructive phase transition to a n...

  1. FTIR study of hydrogen bonding between substituted benzyl alcohols and acrylic esters

    Directory of Open Access Journals (Sweden)

    P. Sivagurunathan

    2016-11-01

    Full Text Available Hydrogen bonding between substituted benzyl alcohols (benzyl alcohol, o-aminobenzyl alcohol, o-chlorobenzyl alcohol and o-nitrobenzyl alcohol and acrylic esters (methyl methacrylate, ethyl methacrylate is studied in carbon tetrachloride by using the FTIR spectroscopic method. Utilizing the Nash method, the formation constant (K of the 1:1 complexes is calculated. Using the K value, the Gibbs free energy change (ΔG0 is also calculated. The calculated formation constant and Gibbs free energy change values vary with the substituent of benzyl alcohol and ester chain length, which suggests that the proton donating ability of substituted benzyl alcohols is in the order: o-aminobenzyl alcohol < benzyl alcohol < o-chlorobenzyl alcohol < o-nitrobenzyl alcohol, and proton accepting ability of acrylic esters is in the order: methyl methacrylate < ethyl methacrylate.

  2. Vinylic polymerization of Norbornenecarboxylic Acid Esters by Palladium Complexes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    New thermoplastic norbornene polymers containing ester groups were prepared byvinylic polymerization of norbornene-carboxylic acid esters by Pd(Ⅱ)-based catalysts. Themonomers were obtained by Diels-Alder reaction of cyclopentadiene with acrylic acid esters(methyl and butyl) as mixtures of endo/exo (ratio 40/60)-isomers and were converted topolymers in 60%~70% conversion. The endo-isomer was less reactive than the exo-isomer.To obtain higher molecular weight the more reactive pure exo-isomer was prepared andpolymerized with the Pd (Ⅱ)-catalysts, tetrakis (acetonitrile) Pd (Ⅱ) bis (tetrafluoroborate)and (η3-allyl)Pd(Ⅱ)SbF6, in high conversion. These polymers showed high glass transitiontemperatures, high transparency and good solubility in common solvents.

  3. Adsorption of surfactants onto acrylic ester resins with different pore size distribution

    Institute of Scientific and Technical Information of China (English)

    YANG Weiben; LI Aimin; CAI Jianguo; MENG Guanhua; ZHANG Quanxing

    2006-01-01

    In this study, a series of acrylic ester resins with different pore size distribution were prepared successfully by varying the type and the amount of pore-forming agents. In order to investigate the adsorption behavior and mechanism of surfactants on acrylic ester resins, three kinds of surfactants were utilized as adsorbates that were sodium 6-dodecyl benzenesulfonate (6-NaDBS),sodium 1-dodecyl benzene sulfonate (1-NaDBS) and sodium 1-dodecyl sulfonate, respectively. It was observed that the surface area was available in a particular pore size and an appropriate pore size of resins appeared to be more important for the adsorption of surfactants. As compared to commercial acrylic ester resins XAD-7 and HP2MG, 50# and 38# resins exhibited more excellent adsorption properties toward 1-NaDBS and 6-NaDBS. The experimental equilibrium data were fitted to the Langmuir, and double-Langmuir models. Two models provided very good fittings for all resins over the temperature range studied. The investigation dicated that electrostatic attraction and hydrogen bond between resins and surfactants were the main forces and had an obvious effect on adsorption process.

  4. Simultanneous determination of five groups content in acrylic acid 2-ethylhexyl ester reaction product by capillary gas chronmatography%气相色谱法测定丙烯酸2-乙基己酯反应产物中5组份的含量

    Institute of Scientific and Technical Information of China (English)

    陆君良; 陈科杰; 邵德贵

    2014-01-01

    采用毛细管气相色谱法同时测定丙烯酸2-乙基己酯反应产物中丙烯酸等5组份的含量。用面积归一法,测定各组份的含量,测定结果的相对标准偏差不大于1.5%(n=5),加标回收率为97.8%~102.5%。%Simultaneous determination of crylic acid etc five groups content in acrylic acid 2-ethylhexyl ester reaction product by capillary gas chronmatography.With the area normalization method ,determinayion of the content each component.The relative standart deviation of results were less than 1.5%(n=5) for five groups ,and recoreries were 97.8%~102.5%.

  5. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... this section are not applicable to ethylene-acrylic acid copolymers used in food-packaging adhesives... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310...

  6. Synthesis, properties and applications of interacting blends of acrylated novalac epoxy resin based poly(ester-amides and vinyl ester

    Directory of Open Access Journals (Sweden)

    Pragnesh N. Dave

    2016-09-01

    Full Text Available Epoxy resin based unsaturated poly(ester-amide resins (UPEAs were prepared by the reported method. These UPEAs were then treated with acryloyl chloride to afford acrylated UPEAs resin (i.e. AUPEAs. Interacting blends of equal proportional AUPEAs and vinyl ester epoxy (VE resin were prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapor pressure osmometer and by IR spectral study and by thermogravimetry. The curing of interacting blends was monitored on differential scanning calorimeter (DSC. Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA.

  7. Fumaric acid esters in dermatology

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2011-01-01

    Full Text Available Fumaric acid esters (FAE are substances of interest in dermatology. FAE exert various activities on cutaneous cells and cytokine networks. So far only a mixture of dimethylfumarate (DMF and three salts of monoethylfumarate (MEF have gained approval for the oral treatment of moderate-to-severe plaque-type psoriasis in Germany. DMF seems to be the major active component. There is evidence that FAE are not only effective and safe in psoriasis but granulomatous non-infectious diseases like granuloma annulare, necrobiosis lipoidica and sarcoidosis. In vitro and animal studies suggest some activity in malignant melanoma as well.

  8. 21 CFR 172.859 - Sucrose fatty acid esters.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sucrose fatty acid esters. 172.859 Section 172.859... CONSUMPTION Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified...) Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are...

  9. Conversion of carbohydrates to levulinic acid esters

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to the field of converting carbohydrates into levulinic acid, a platform chemical for many chemical end products. More specifically the invention relates to a method for converting carbohydrates such as mono-, di- or polysaccharides, obtained from for example biomass...... production into a suitable levulinic acid ester in the presence of a zeolite or zeotype catalyst and a suitable alcohol, and the ester may be further converted into levulinic acid if desired....

  10. Anticholinesterase activity of fluorochloronitroacetic acid esters

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Yu.Ya.; Brel, V.K. Martynov, I.V.

    1984-11-01

    Results are presented from pharmacologic and biochemical experiments leading to the conclusion that fluorochloronitroacetic acid esters have anticholinesterase activity. Since the esters caused muscular weakness in mice, experiments were performed on isolated tissue preparation. The biochemical experiments consisted of finding the biomolecular constants of irreversible inhibition of acetylcholinesterase by the esters, using acetylcholinesterase from human erythrocytes, as well as horse serum cholinesterase. The ethyl and n-propyl esters of halogen nitroacetic acid were used in all experiments. It was found that the propyl ester caused an increase in the force of individual contractions in the isolated muscle specimens, plus an inability of the muscle to retain tetanus. The substances were determined to have an anticholinesterase effect. The mechanism of cholinesterase inhibition is not yet known. It is probable that the substances acylate the serine hydroxyl of the esterase center of the cholinestersase. 7 references, 1 figure.

  11. SYNTHESIS AND PHOTOCHROMISM OF ACRYLIC ESTER COPOLYMERS BEARING PENDANT VIOLOGEN GROUPS

    Institute of Scientific and Technical Information of China (English)

    SUN Xuehui; YANG Yukun

    1996-01-01

    A series of acrylic ester copolymers with viologen group as pendant were synthesized through the reaction of MMA-EBA (Ethenyl bromoacetate) copolymer with 4-(4'-pyridyl)-N-alkyl (or arylalkyl) pyridiniums. These viologen copolymers can exchange their anion with NH4PF6 in methanol to improve their solubility in organic solvents such as DMF and acetone. Compared with the corresponding low molecular viologens, these viologen copolymers have relatively lower color development rate under UV light and fade faster in air due to less affinity to photo-reductant and deficiency of association between their cation radicals. Their photofatigue resistant ability is also slightly better than that of low molecular viologens.

  12. Decarboxylation-based traceless linking with aroyl acrylic acids

    DEFF Research Database (Denmark)

    Nielsen, John

    1998-01-01

    beta-Keto carboxylic acids are known to decarboxylate readily. In our pursuit to synthesize beta-indolinyl propiophenones, we have exploited this chemistry as a mean of establishing a traceless handle. 2-Aroyl acrylic acids have been esterified to a trityl resin, after which Michael-type addition...

  13. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyglycerol esters of fatty acids. 172.854 Section... HUMAN CONSUMPTION Multipurpose Additives § 172.854 Polyglycerol esters of fatty acids. Polyglycerol esters of fatty acids, up to and including the decaglycerol esters, may be safely used in food...

  14. 40 CFR 721.9640 - Salt of an acrylic acid - acrylamide terpolymer (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Salt of an acrylic acid - acrylamide... Specific Chemical Substances § 721.9640 Salt of an acrylic acid - acrylamide terpolymer (generic). (a... generically as salt of an acrylic acid - acrylamide terpolymer (PMN P-99-817) is subject to reporting...

  15. Acrylic acid and electric power cogeneration in an SOFC reactor.

    Science.gov (United States)

    Ji, Baofeng; Wang, Jibo; Chu, Wenling; Yang, Weishen; Lin, Liwu

    2009-04-21

    A highly efficient catalyst, MoV(0.3)Te(0.17)Nb(0.12)O, used for acrylic acid (AA) production from propane, was used as an anodic catalyst in an SOFC reactor, from which AA and electric power were cogenerated at 400-450 degrees C.

  16. Use of Acrylic Acid Sodium Acrylate Polymer to Maintain Cocoa Seed Viability

    Directory of Open Access Journals (Sweden)

    Pudji Rahardjo

    2010-08-01

    Full Text Available The main problem of cocoa seed storage is moisture content of the seeds because cocoa seeds will germinate if cocoa seeds moisture content is high. The objective of this research is to maintain the cocoa seeds viability in storage using acrylic acid sodium acrylate polymer (AASAP. The function of AASAP is to absorb humidity in storage due to their ability to retain water and to prevent water loss. The experiment was conducted in a laboratory of Indonesian Coffee and Cocoa Research Institute and in Kaliwining Experimental Garden. This experiment was arranged by factorial randomized complete design, in wich AASAP dosages 0%; 0.1% (0.1 g/100 seeds; 0.2% (0.2 g/100 seeds, 0.3% (0.3 g/100 seeds, 0,4% (0,4g/100 seeds, combined with seeds storage period 1, 2, 3 and 4 weeks. The experiment used 3 replications and each repli cation used 100 seeds. Parameter of observation consisted of percentage of seeds germinated in storage, percentage of seeds infected by fungi in storage, seeds moisture content, percentage of seeds germination after storage, and early growth of cocoa seedlings. The results of the experiment showed that AASAP application with some dosages cocoa seeds storage cause to germinate in storage during 2 weeks. AASAP application with some dosages in cocoa seeds storage for 2 weeks would not result in infection by fungi and did not significantly affect seed germination after storage for 1, 2 and 4 weeks, and percentage of germination of cocoa seed after storage for 3 weeks decreased with increase dosage of AASAP. Higher dosage of AASAP would reduce early growth of cocoa seedling. Key words : Theobroma cacao, seed, acrylic acid sodium acrylate, seed storage, viabilty.

  17. Dipentaerythritol penta-acrylate phosphate - an alternative phosphate ester monomer for bonding of methacrylates to zirconia

    Science.gov (United States)

    Chen, Ying; Tay, Franklin R.; Lu, Zhicen; Chen, Chen; Qian, Mengke; Zhang, Huaiqin; Tian, Fucong; Xie, Haifeng

    2016-12-01

    The present work examined the effects of dipentaerythritol penta-acrylate phosphate (PENTA) as an alternative phosphate ester monomer for bonding of methacrylate-based resins to yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) and further investigated the potential bonding mechanism involved. Shear bond strength testing was performed to evaluate the efficacy of experimental PENTA-containing primers (5, 10, 15, 20 or 30 wt% PENTA in acetone) in improving resin-Y-TZP bond strength. Bonding without the use of a PENTA-containing served as the negative control, and a Methacryloyloxidecyl dihydrogenphosphate(MDP)-containing primer was used as the positive control. Inductively coupled plasma-mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) were used to investigate the potential existence of chemical affinity between PENTA and Y-TZP. Shear bond strengths were significant higher in the 15 and 20 wt% PENTA groups. The ICP-MS, XPS and FTIR data indicated that the P content on the Y-TZP surface increased as the concentration of PENTA increased in the experimental primers, via the formation of Zr–O–P bond. Taken together, the results attest that PENTA improves resin bonding of Y-TZP through chemical reaction with Y-TZP. Increasing the concentration of PENTA augments its binding affinity but not its bonding efficacy with zirconia.

  18. Naturally Occurring Cinnamic Acid Sugar Ester Derivatives

    Directory of Open Access Journals (Sweden)

    Yuxin Tian

    2016-10-01

    Full Text Available Cinnamic acid sugar ester derivatives (CASEDs are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depressant and brains protective activities have made them a topic of great interest over the past several decades. In particular the compound 3′,6-disinapoylsucrose, the index component of Yuanzhi (a well-known Traditional Chinese Medicine or TCM, presents antidepressant effects at a molecular level, and has become a hotspot of research on new lead drug compounds. Several other similar cinnamic acid sugar ester derivatives are reported in traditional medicine as compounds to calm the nerves and display anti-depression and neuroprotective activity. Interestingly, more than one third of CASEDs are distributed in the family Polygalaceae. This overview discusses the isolation of cinnamic acid sugar ester derivatives from plants, together with a systematic discussion of their distribution, chemical structures and properties and pharmacological activities, with the hope of providing references for natural product researchers and draw attention to these interesting compounds.

  19. 75 FR 71556 - Polyoxyalkylated Glycerol Fatty Acid Esters; Tolerance Exemption

    Science.gov (United States)

    2010-11-24

    ... AGENCY 40 CFR Part 180 Polyoxyalkylated Glycerol Fatty Acid Esters; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of polyoxyalkylated glycerol fatty acid esters; the... ethylene oxide or propylene oxide, also known as polyoxyalkylated glycerol fatty acid esters, when used...

  20. 40 CFR 721.1732 - Nitrobenzoic acid octyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Nitrobenzoic acid octyl ester. 721... Substances § 721.1732 Nitrobenzoic acid octyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as nitrobenzoic acid octyl ester (PMN...

  1. 40 CFR 721.5310 - Neononanoic acid, ethenyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Neononanoic acid, ethenyl ester. 721... Substances § 721.5310 Neononanoic acid, ethenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as neononanoic acid, ethenyl ester (PMN...

  2. 40 CFR 721.4158 - Hexadecanoic acid, ethenyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexadecanoic acid, ethenyl ester. 721... Substances § 721.4158 Hexadecanoic acid, ethenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as hexadecanoic acid, ethenyl ester (PMN...

  3. 40 CFR 721.4215 - Hexanedioic acid, diethenyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexanedioic acid, diethenyl ester. 721... Substances § 721.4215 Hexanedioic acid, diethenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as hexanedioic acid, diethenyl ester (PMN...

  4. Polymerization of acrylic acid using atmospheric pressure DBD plasma jet

    Science.gov (United States)

    Bashir, M.; Bashir, S.

    2016-08-01

    In this paper polymerization of acrylic acid was performed using non thermal atmospheric pressure plasma jet technology. The goal of this study is to deposit organic functional coatings for biomedical applications using a low cost and rapid growth rate plasma jet technique. The monomer solution of acrylic acid was vaporized and then fed into the argon plasma for coating. The discharge was powered using a laboratory made power supply operating with sinusoidal voltage signals at a frequency of 10 kHz. The optical emission spectra were collected in order to get insight into the plasma chemistry during deposition process. The coatings were characterized using Fourier transform infrared spectroscopy, atomic force microscopy and growth rates analysis. A high retention of carboxylic functional groups of the monomer was observed at the surface deposited using this low power technique.

  5. Reactivity Ratios of Diethyldiallylammonium Chloride with Acrylamide or Acrylic Acid

    Institute of Scientific and Technical Information of China (English)

    Li Hua LIU; Zhi Qiang LIU; Zhu Qing GONG

    2006-01-01

    The compositions of copolymers of diethyldiallylammonium chloride (DEDAAC) with acrylamide (AM), acrylic acid (AA) or sodium acrylic acid (NaAA) at low conversion were determined by elemental analysis, and the reactivity ratios of monomers in copolymerization were obtained by Kelen-Tudos method. The results showed that the reactivity ratios rDE and rAM are 0.31 and 5.27 for DEDAAC with AM, rDE and rAA are 0.28 and 5.15 for DEDAAC with AA, and rDE and rNaAA are 0.40 and 3.97 for DEDAAC with NaAA, respectively. The copolymerizations for DEDAAC with AM, AA or NaAA are non-ideal copolymerization and the products are random copolymers.

  6. Hemocompatibility of Chitosan/poly(acrylic acid) Grafted Polyurethane Tubing

    OpenAIRE

    Lee, Hyun-Su; Tomczyk, Nancy; Kandel, Judith; Composto, Russell J.; Eckmann, David M.

    2013-01-01

    The activation and adhesion of platelets or whole blood exposed to chitosan (CH) grafted surfaces is used to evaluate the hemocompatibility of biomaterials. The biomaterial surfaces are polyurethane (PU) tubes grafted with an inner poly(acrylic acid) (PAA) and an outer CH or quaternary ammonium modified CH (CH-Q) brush. The CH, CH-Q and PAA grafted layers were characterized by ellipsometry and fluorescence microscopy. Material wear tests demonstrate that CH (CH-Q) is stably grafted onto PU tu...

  7. CONFORMATIONAL CHARACTERISTICS OF POLY(ACRYLIC ACID) AND POLY(METHACRYLIC ACID)

    Institute of Scientific and Technical Information of China (English)

    HE Ziru; YANG Xiaozhen; ZHAO Delu; XU Mao; HAN Dong; YE Meiling; SHI Lianghe

    1997-01-01

    A full-relaxation optimization of molecule and the Dreiding force field are employed to obtain the geometry parameters and the conformational energy surfaces of meso or racemic dyad of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA). Three different carbonyl-bond orientations of side-groups resulted in the differences in depth of potential wells in their energetic contours for a meso or a racemic dyad.These discrepancies are interpreted as a result of various fine structures corresponding to grid search conformations as well as thereby different interactions. The analysis on the most stable conformations of PMAA confirmed that the ester groups are nearly perpendicular to the plane defined by the two adjacent skeletal bonds but may possibly change their relative orientations to meet the requirement of lower energy during the conformational state transition. For each polymer, two global energy maps of a meso and a racemic dyad were finally constructed from the superposition of energy data for the three kinds of side-group orientations by the Boltzmann factors. From an ensemble average, the proposed scheme with three rotational isomeric states (RIS) allowed us to access the experimentally unperturbed dimensions of PAA chain via the configurational statistical mechanics. Although the calculation was based on the short-range, local interactions, it was interested to note that the experimental characteristic ratios just fell within the range calculated for atactic chains.

  8. An overview of the properties of fatty acid alkyl esters

    Science.gov (United States)

    Fatty acid alkyl esters of plant oils, especially in the form of methyl esters, have numerous applications with fuel use having received the most attention in recent times due to the potential high volume. Various properties imparted by neat fatty acid alkyl esters have been shown to influence fuel ...

  9. Affinity labelling enzymes with esters of aromatic sulfonic acids

    Science.gov (United States)

    Wong, Show-Chu; Shaw, Elliott

    1977-01-01

    Novel esters of aromatic sulfonic acids are disclosed. The specific esters are nitrophenyl p- and m-amidinophenylmethanesulfonate. Also disclosed is a method for specific inactivation of the enzyme, thrombin, employing nitrophenyl p-amidinophenylmethanesulfonate.

  10. Bioactive caffeic acid esters from Glycyrrhiza glabra.

    Science.gov (United States)

    Dey, Surajit; Deepak, Mundkinajeddu; Setty, Manjunath; D'Souza, Prashanth; Agarwal, Amit; Sangli, Gopal Krishna

    2009-01-01

    Thin layer chromatography bioautography (using DPPH spray reagent) guided fractionation of Glycyrrhiza glabra led to the isolation of two caffeic acid derivative esters, viz. eicosanyl caffeate (1) and docosyl caffeate (2). The two compounds exhibited potent elastase inhibitory activity, with IC(50) values of 0.99 microg mL(-1) and 1.4 microg mL(-1) for 1 and 2, respectively. The compounds also showed moderate antioxidant activity in DPPH and ABTS scavenging assays. The results indicate a possible role of caffeic acid derivatives, in addition to flavonoids in the anti-ulcer properties of G. glabra.

  11. 40 CFR 721.10147 - Acrylate derivative of alkoxysilylalkane ester and mixed metal oxides (generic).

    Science.gov (United States)

    2010-07-01

    ... alkoxysilylalkane ester and mixed metal oxides (generic). 721.10147 Section 721.10147 Protection of Environment... alkoxysilylalkane ester and mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to... ester and mixed metal oxides (PMN P-07-198) is subject to reporting under this section for...

  12. Conformational Transition of Poly (Acrylic Acid) Detected by Microcantilever Sensing

    Institute of Scientific and Technical Information of China (English)

    LI Kai; LIU Hong; ZHANG Qing-Chuan; XUE Chang-Guo; WU Xiao-Ping

    2007-01-01

    Poly (acrylic acid) (PAA) chains are grafted on one side of a microcantilever by the self-assembled method and the deflections of the microcantilever are detected as a function of medium pH from 3 to 11. It is found that when the pH varies, the microcantilever deflects because of the changing surface stress. By analysing the electrostatic repulsive effect, the surface stress change is related to the conformation transition of PAA from a collapse state to a swelling state. This method offers the interaction information among the polymer chains during the conformational transition and affords an alternative way to study conformational change of polymers.

  13. Poly(styrene-acrylic acid) magnetic polymer microspheres

    Institute of Scientific and Technical Information of China (English)

    Yanling CHENG; Liuqiang MA; Ruohui LI

    2008-01-01

    Magnetic polymer microspheres have been considered as a kind of new biopolymer materials with great advantages in bioseparation engineering and biome-dicine engineering because they have not only polymer functional groups but also magnetic characteristics. Styrene-acrylic acid copolymer (p(S-AA)) magnetic microspheres were synthesized by dispersion polymeriza-tion with Fe3O4 as core and p(S-AA) as shell. The micro-spheres were characterized by SEM, size analysis, molecular weight and solid content measurement. All of them indicate that the microspheres are small in size, nar-row in distribution, stable in chemistry and rich in func-tional groups on their surface.

  14. Preparation of Poly(acrylic acid) Hydrogel by Radiation Crosslinking and Its Application for Mucoadhesives

    OpenAIRE

    Young-Chang Nho; Jong-Seok Park; Youn-Mook Lim

    2014-01-01

    A mucoadhesive drug delivery system can improve the effectiveness of a drug by maintaining the drug concentration and allowing targeting and localization of the drug at a specific site. Acrylic-based hydrogels have been used extensively as a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, poly(acrylic acid) was selected to prepare the bioadhesive hydrogel adhering to mucosal surfaces using a radiation process. Poly(acrylic acid) was dissolved in ...

  15. Methods of refining and producing isomerized fatty acid esters and fatty acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.; Beltran, Leslie V.; Kunz, Linda A.; Pals, Tessa M.; Quinn, Jordan R; Behrends, Jr., Raymond T.; Bernhardt, Randal J.

    2016-07-05

    Methods are provided for refining natural oil feedstocks and producing isomerized esters and acids. The methods comprise providing a C4-C18 unsaturated fatty ester or acid, and isomerizing the fatty acid ester or acid in the presence of heat or an isomerization catalyst to form an isomerized fatty ester or acid. In some embodiments, the methods comprise forming a dibasic ester or dibasic acid prior to the isomerizing step. In certain embodiments, the methods further comprise hydrolyzing the dibasic ester to form a dibasic acid. In certain embodiments, the olefin is formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having unsaturated esters.

  16. 40 CFR 721.2950 - Carboxylic acid glycidyl esters.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Carboxylic acid glycidyl esters. 721... Substances § 721.2950 Carboxylic acid glycidyl esters. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as carboxylic acid glycidyl...

  17. 40 CFR 721.3110 - Polycarboxylic acid ester (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polycarboxylic acid ester (generic... Substances § 721.3110 Polycarboxylic acid ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polycarboxylic acid...

  18. 40 CFR 721.8660 - Propionic acid methyl ester (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Propionic acid methyl ester (generic... Substances § 721.8660 Propionic acid methyl ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a propionic acid methyl...

  19. Graft copolymerization of acrylic acid onto polyamide fibers

    Science.gov (United States)

    Makhlouf, Chahira; Marais, Stéphane; Roudesli, Sadok

    2007-04-01

    The grafting of acrylic acid (AA) monomer (CH 2dbnd CH sbnd COOH) on polyamide 6.6 monofilaments (PA 6.6) using benzoyl peroxide (BPO) as initiator was carried out in order to enhance the hydrophilic nature of fibers. The grafting rate depends on the AA concentration, the BPO concentration, the time and the temperature of reaction. The best conditions for optimum rate of grafting were obtained with a AA concentration of 0.5 M, a BPO concentration of 0.03 M, a reaction temperature of T = 85 °C and a reaction time of 120 mn. The fiber surface has been investigated by many experimental techniques of characterization such as Fourier transform infrared spectroscopy (FTIR), calorimetric analysis (DSC), scanning electron microscopy (SEM), and contact angle measurements. The effect of grafting of acrylic acid onto PA 6.6 fibers on their moisture and mechanical resistances was analyzed from water sorption and elongation at break measurements. The analysis of the experimental data shows clearly the efficiency of the grafting reaction used, leading to a significant increase of the hydrophilic character of the PA 6.6 surface.

  20. Plasma polymerization of acrylic acid onto polystyrene by cyclonic plasma at atmospheric pressure

    Science.gov (United States)

    Chang, Yi-Jan; Lin, Chin-Ho; Huang, Chun

    2016-01-01

    The cyclonic atmospheric-pressure plasma is developed for chamberless deposition of poly(acrylic acid) film from argon/acrylic acid mixtures. The photoemission plasma species in atmospheric-pressure plasma polymerization was identified by optical emission spectroscopy (OES). The OES diagnosis data and deposition results indicated that in glow discharge, the CH and C2 species resulted from low-energy electron-impact dissociation that creates deposition species, but the strong CO emission lines are related to nondeposition species. The acrylic acid flow rate is seen as the key factor affecting the film growth. The film surface analysis results indicate that a smooth, continuous, and uniform surface of poly(acrylic acid) films can be formed at a relatively low plasma power input. This study reveals the potential of chamberless film growth at atmospheric pressure for large-area deposition of poly(acrylic acid) films.

  1. Phenylpropanoid acid esters from Korean propolis and their antioxidant activities.

    Science.gov (United States)

    Lee, In-Kyoung; Han, Myung-Suk; Kim, Dae-Won; Yun, Bong-Sik

    2014-08-01

    Ten phenylpropanoic acid esters were isolated from an ethanolic extract of Korean propolis. Their structures were elucidated by spectroscopic methods including NMR and ESI-MS. Caffeic acid esters with catechol moiety exhibited significant ABTS and DPPH radical scavenging activity and protective effect against DNA damage by a Fenton reaction.

  2. Phthalic acid esters found in municipal organic waste

    DEFF Research Database (Denmark)

    Hartmann, Hinrich; Ahring, Birgitte Kiær

    2003-01-01

    Contamination of the organic fraction of municipal solid waste (OFMSW) with xenobiotic compounds and their fate during anaerobic digestion was investigated. The phthalic acid ester di-(2- ethylhexyl)phthalate (DEHP) was identified as the main contaminant in OFMSW in concentrations more than half...... matter with high biogas yields and efficient reduction of the phthalic acid ester contamination....

  3. Swelling Behaviors of Polyaniline-Poly(Acrylic Acid) Hydrogels

    Institute of Scientific and Technical Information of China (English)

    ZHANG You-wei; ZHAO Jiong-xin; LI Xiao-feng; TAO Yong; WU Cheng-xun

    2005-01-01

    Using poly(acrylic acid) (PAA) aqueous solution, NaOH aqueous solution, aniline(An) and ammonim persulfate(APS), PAn-PAA hydrogels with a semi-interpenetrating structure connected by physical interlocks, chemical ion bonds and hydrogen bonds wcre prepared. The swelling properties of the hydrogels in solutions of different pH values(adjusted by adding NaOH or HCl) were studied. All the hydrogels prepared have similar swelling curves (the curves of equilibrium swelling ratio vs. pH value) and reach their maximum swelling at pH of 8 - 10. The maximum swelling ratio of the hydrogels is dependent on composition, including molecular weight of PAA, polymer content of the hydrogel,and molar ratios of AA to An, APS to An, and NaOH to AA.And the compositional dependence of the swelling capacity of PAn-PAA hydrogels was also studied.

  4. Polymerisation by acrylamide and acrylic acid inverse suspension

    Directory of Open Access Journals (Sweden)

    Sergio Alejandro LLoreda Blanco

    2010-04-01

    Full Text Available This work describes polymerisation by inverse suspension of acrylamide monomers and acrylic acid for forming homopolymers or copolymers This type of polymersitaion's advantages are described and reasons given for why it should be studied. The article stresses the importance of these types of monomer for obtaining materials presenting great affinity for water, such as super-absorbents and controlled liberation mechanism. Important aspects are presented such as type of initiation, monomer composition and continuous phase composition; parameters are described offering an important basis for formulating a system leading to successfully obtaining the desired materials' most relevant characteristics such as particle distribution and size polymerisation kinetics, conversion and water absorption capacity respecting the system's modifiable parameters. The foregoing is important since the product can be modified, bestowing propierties on it which are suitable for its use.

  5. New initiation system for polymerization of acryl acid

    Institute of Scientific and Technical Information of China (English)

    LI Hai-pu; ZHONG Hong; CHEN Qi-yuan; YIN Zhou-lan

    2005-01-01

    The redox initiation system for polyacrylate sodium of high molecular mass was designed and its effect with varying component dosage on the degree of polymerization was investigated. The results show that the proper type and amount of inorganic salt, as well as amine initiator, are conductive to the increase of degree of polymerization. The fine ingredient of the initiation system is as follows:the dosages of amine, persulphate and inorganic salt are 0.75%, 0.10% and 1.00% by mass based on acryl acid respectively, the molar ratio of sulphite to the persulphate is 1:1. Under such conditions the degree of polyacrylate can reach 7.43×107 with a acceptable polymerization time for industrial production.

  6. Preparation of an imogolite/poly(acrylic acid) hybrid gel.

    Science.gov (United States)

    Lee, Hoik; Ryu, Jungju; Kim, Donghyun; Joo, Yongho; Lee, Sang Uck; Sohn, Daewon

    2013-09-15

    Many efforts in the field of hydrogels have been focused toward increasing the mechanical strength of the gel using inorganic materials. In this study, we synthesized a hydrogel that has excellent mechanical properties using surface-modified inorganic nanofibers composed of imogolite (Al2SiO3(OH)4), which is a hydrated aluminum silicate that has a hollow tube structure. Gamma ray radiation generates peroxide radicals on the nanofibers (imogolite), resulting in an additive free hybrid hydrogel. Structural optimization was carried out by changing the composition of imogolite and poly(acrylic acid). Chemical bonding between the nanofiber and the polymer was simulated by a cluster model and characterized by wide area Raman spectroscopy. The results indicate that imogolite embedded in a polymer matrix can align along the direction of an elongational force, as confirmed by small angle X-ray scattering (SAXS).

  7. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle...

  8. Expanding the modular ester fermentative pathways for combinatorial biosynthesis of esters from volatile organic acids.

    Science.gov (United States)

    Layton, Donovan S; Trinh, Cong T

    2016-08-01

    Volatile organic acids are byproducts of fermentative metabolism, for example, anaerobic digestion of lignocellulosic biomass or organic wastes, and are often times undesired inhibiting cell growth and reducing directed formation of the desired products. Here, we devised a general framework for upgrading these volatile organic acids to high-value esters that can be used as flavors, fragrances, solvents, and biofuels. This framework employs the acid-to-ester modules, consisting of an AAT (alcohol acyltransferase) plus ACT (acyl CoA transferase) submodule and an alcohol submodule, for co-fermentation of sugars and organic acids to acyl CoAs and alcohols to form a combinatorial library of esters. By assembling these modules with the engineered Escherichia coli modular chassis cell, we developed microbial manufacturing platforms to perform the following functions: (i) rapid in vivo screening of novel AATs for their catalytic activities; (ii) expanding combinatorial biosynthesis of unique fermentative esters; and (iii) upgrading volatile organic acids to esters using single or mixed cell cultures. To demonstrate this framework, we screened for a set of five unique and divergent AATs from multiple species, and were able to determine their novel activities as well as produce a library of 12 out of the 13 expected esters from co-fermentation of sugars and (C2-C6) volatile organic acids. We envision the developed framework to be valuable for in vivo characterization of a repertoire of not-well-characterized natural AATs, expanding the combinatorial biosynthesis of fermentative esters, and upgrading volatile organic acids to high-value esters. Biotechnol. Bioeng. 2016;113: 1764-1776. © 2016 Wiley Periodicals, Inc.

  9. Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

    Energy Technology Data Exchange (ETDEWEB)

    Ghim, Deoukchen; Kim, Jung Hyeun [University of Seoul, Seoul (Korea, Republic of)

    2016-02-15

    Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T{sub g} of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

  10. Preparation of esters of gallic acid with higher primary alcohols

    NARCIS (Netherlands)

    Kerk, G.J.M. van der; Verbeek, J.H.; Cleton, J.C.F.

    1951-01-01

    The esters of gallic acid and higher primary alcohols, especially fatty alcohols, have recently gained considerable interest as possible antioxidants for fats. Two independent methods for the preparation of these esters are described. In the first method the hitherto unknown compound galloyl chlorid

  11. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Science.gov (United States)

    2010-07-01

    ..., phosphoric acid ester salts. 721.6200 Section 721.6200 Protection of Environment ENVIRONMENTAL PROTECTION... ester salts. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified as fatty acid polyamine condensate, phosphate ester salts (PMNs P-90-1984 and...

  12. Studies on LCST of poly (N-isopropylacrylamide-co-acrylic acid-co-N-diacetone acrylamide)

    Institute of Scientific and Technical Information of China (English)

    Cai Hua Ni; Xiao Xia Zhu; Qing Lan Wang; Xian Yu Zeng

    2007-01-01

    Linear copolymers from N-isopropylacrylamide (NIPA), acrylic acid (AA) and diacetone acrylamide (DAA) have been prepared.The effect of composition, ionic strength and pH on their lower critical solution temperature (LCST) has been investigated.

  13. Emulsion polymerization of polystyrene-co-acrylic acid with Cu2O incorporation

    Science.gov (United States)

    Fahmiati, Sri; Harmami, Sri Budi; Meliana, Yenny; Haryono, Agus

    2017-01-01

    In this research, poly(styrene-co-acrylic acid-Cu) was prepared via emulsion polymerization.Cu contents were varied as 10%, 15% and 20% and mol ratio of styrene to acrylic acid as 1:1 and 2:1. Structure and surface of poly(styrene-co-acrylic acid-Cu) were characterized by FTIR (Fourier Transformed Infra Red), NMR (Nuclear Magnetic Resonance), and SEM/EDX (Scanning Electron Microcope/ Energy Dispersive X-Ray) spectroscopy. The NMR spectra showed that the polymer was formed, however FTIR spectra showed that there were still unreacted monomers. SEM-EDX confirmed that copper (Cu) was dispersed uniformly on poly(styrene-co-acrylic acid-Cu) matrix.

  14. CATALYTIC HYDROGENATION OF ACRYLATE ASMMETRIC Dd(Ⅱ)—CHELATING RESINS CONTAINING AMINO ACID LIGANDS

    Institute of Scientific and Technical Information of China (English)

    Wangying; WangHongzuo; 等

    1995-01-01

    The catalytic hydrogenation of palladium chelating resins containing chiral amino acid ligands based on lower crosslinked poly(chloroethyl acrylate) and some effects on the rate of hydrogenation were studied.

  15. Synthesis and characterization of amylose grafted poly(acrylic acid) and its application in ammonia adsorption.

    Science.gov (United States)

    Chen, Qing; Yu, Haojie; Wang, Li; Abdin, Zain-Ul; Yang, Xinpeng; Wang, Junhua; Zhou, Weidong; Zhang, Hongtao; Chen, Xiao

    2016-11-20

    Amylose grafted poly(acrylic acid) (Am-g-PAA) was synthesized by graft copolymerization of amylose with acrylic acid. The structure of Am-g-PAA was confirmed by (1)H NMR and FT-IR spectra. The morphology, crystallinity and thermal properties of amylose and Am-g-PAA were investigated by SEM, XRD and TGA, respectively. The highest degree of substitution (DS) of carboxyl group was 1.96 which was obtained after reacted for 1h at 60°C. Acrylic acid to anhydroglucose mole ratio for DS was 19.81. It was found that a large number of carboxyl groups were grafted on the backbone of amylose. It was also found that ammonia adsorption capacity of amylose increased by grafting poly(acrylic acid) on the backbone of amylose.

  16. Synthesis and Properties of IPN Hydrogels Based on Konjac Glucomannan and Poly(acrylic acid)

    Institute of Scientific and Technical Information of China (English)

    Bing LIU; Zhi Lan LIU; Ren Xi ZHUO

    2006-01-01

    Novel interpenetrating polymer network (IPN) hydrogels based on konjac glucomannan (KGM) and poly(acrylic acid) (PAA) were prepared by polymerization and cross-linking of acrylic acid (AA) in the pre-fabricated KGM gel. The IPN gel was analyzed by FT-IR. The studies on the equilibrium swelling ratio of IPN hydrogels revealed their sensitive response to environmental pH value. The results of in vitro degradation showed that the IPN hydrogels retain the enzymatic degradation character of KGM.

  17. Preparation and Property of Acrylic Acid Rare Earth Complex and Its Hydrosilylation

    Institute of Scientific and Technical Information of China (English)

    Zhang Ming; Chen Haiyan; Chen Xiaosong; Dai Shaojun; Inoue Shinich; Okamoto Hiroshi

    2004-01-01

    Acrylic acid rare earth complex was prepared. Its chemical composition was determined by chemical and elemental analysis, and its structure as well as properties was characterized using IR, Fluorescence and UV spectrum, and its solubility was also investigated. Meanwhile a kind of elastic functional polymer with rare earth units in the side chains was produced. It is confirmed by IR spectrum that the Si-H bonds really react with acrylic acid rare earth.

  18. FT-RAMAN SPECTROSCOPY FOR MONITORING THE POLYMERIZATION OF ACRYLIC ACID IN AQUEOUS SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Jiang Yu; Hui-zhou Liu; Jia-yong Chen

    1999-01-01

    FT-Raman spectroscopy was used to monitor the polymerization of acrylic acid in aqueous solution. A simple method to avoid the noise in the background during the signal processing via Fourier transformation was used in this work. The effects of the amount of initiator used on the polymerization are studied. When the amount of the initiator in the polymerization was increased, both the rate and extent of polymerization of acrylic acid will be increased.

  19. Modification of polyamide 6.6 dyeing properties by grafting with poly(acrylic acid)

    OpenAIRE

    Miranda, Teresa; Santos, Jorge Gomes; Soares, Graça M. B.

    2012-01-01

    978-972-8063-67-2 The wet chemical surface modification continues to be a growing area of research interest. This study describes preparation and characterization of poly (acrylic acid)-grafted polyamide 6.6 fabric. Poly(acrylic acid) has been grafted onto polyamide backbone using benzoyl peroxide (BPO) as catalyst in aqueous medium. The benzoyl peroxide initiator optimum concentration was 0.03 M. The best conditions for optimum grafting reaction were reaction time 120 min, grafting tem...

  20. Triterpene hexahydroxydiphenoyl esters and a quinic acid purpurogallin carbonyl ester from the leaves of Castanopsis fissa.

    Science.gov (United States)

    Huang, Yong-Lin; Tsujita, Takaaki; Tanaka, Takashi; Matsuo, Yosuke; Kouno, Isao; Li, Dian-Peng; Nonaka, Gen-ichiro

    2011-11-01

    Triterpene hexahydroxydiphenoyl (HHDP) esters have only been isolated from Castanopsis species, and the distribution of these esters in nature is of chemotaxonomical interest. In this study, the chemical constituents of the leaves of Castanopsis fissa were examined in detail to identify and isolate potential HHDP esters. Together with 53 known compounds, 3,4-di-O-galloyl-1-O-purpurogallin carbonyl quinic acid (1) and 3,24-(S)-HHDP-2α,3β,23,24-tetrahydroxytaraxastan-28,20β-olide (2) were isolated and their structures were elucidated by spectroscopic and chemical methods. The polyphenols of the leaves were mainly composed of galloyl quinic acids, triterpenes HHDP esters, ellagitannins and flavonol glycosides. In particular, the isolation yields of 1,3,4-trigalloyl quinic acid and compound 2 were 1.53% and 0.27%, respectively, from the fresh leaves. The presence of lipid soluble HHDP esters of oleanane-type triterpenes as one of the major metabolites is an important chemotaxonomical discovery. Lipase inhibition activities and ORAC values of the major constituents were compared. The triterpene HHDP ester showed moderate lipase inhibition activity and myricitrin gave the largest ORAC value.

  1. Controlled Transdermal Iontophoresis by Polypyrrole/Poly(Acrylic Acid) Hydrogel

    Science.gov (United States)

    Chansai, Phithupha; Sirivat, Anuvat

    2008-03-01

    Transdermal drug delivery system delivers a drug into a body at desired site and rate. The conductive polymer-hydrogel blend between polypyrrole (PPy) doped with anionic drug and poly(acrylic acid) (PAA) were developed as a matrix/carrier of drug for the transdermal drug delivery in which the characteristic releases depend on the electrical field applied. The PAA films and their blend films were prepared by solution casting using ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent. A mechanical blending of PPy particles and PAA matrix was then carried out. Drug diffusions in the blended PPy/PAA hydrogel and the non-blended one were investigated and determined by using a modified Franz-diffusion cell with an acetate buffer, pH 5.5, at 37 0C, for a period of 48 hours to determine the effects of crosslinking ratio and electric field strength. Amounts of the released drug were measured by UV-Visible spectrophotometry. The diffusion coefficient of drug was determined through the Higuchi equation via different conditions, with and without an electric field. Moreover, thermal properties and electrical conductivity of the polypyrrole and drug-loaded polypyrrole were investigated by means of the thermogravimetric analysis and by using a two-point probe meter, respectively.

  2. Interaction of photosensitive surfactant with DNA and poly acrylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Zakrevskyy, Yuriy, E-mail: yuriy.zakrevskyy@fh-koeln.de; Paasche, Jens; Lomadze, Nino; Santer, Svetlana, E-mail: santer@uni-potsdam.de [Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam (Germany); Cywinski, Piotr; Cywinska, Magdalena; Reich, Oliver; Löhmannsröben, Hans-Gerd [Physical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam (Germany)

    2014-01-28

    In this paper, we investigate interactions and phase transitions in polyelectrolyte-surfactant complexes formed between a cationic azobenzene-containing surfactant and two types of polyelectrolytes: natural (DNA) or synthetic (PAA: poly acrylic acid). The construction of a phase diagram allowed distancing between four major phases: extended coil conformation, colloidally stable compacted globules, colloidal instability range, and surfactant-stabilized compact state. Investigation on the complexes’ properties in different phases and under irradiation with UV light provides information about the role of the surfactant's hydrophobic trans isomers both in the formation and destruction of DNA and PAA globules as well as in their colloidal stabilization. The trans isomer shows much stronger affinity to the polyelectrolytes than the hydrophilic cis counterpart. There is no need for complete compensation of the polyelectrolyte charges to reach the complete compaction. On contrary to the findings previously reported in the literature, we demonstrate – for the first time – complete polyelectrolyte compaction which occurs already at 20% of DNA (and at 50% of PAA) charge compensation. The trans isomer plays the main role in the compaction. The aggregation between azobenzene units in the photosensitive surfactant is a driving force of this process. The decompaction can be realized during UV light irradiation and is strongly influenced by the interplay between surfactant-surfactant and surfactant-DNA interactions in the compacted globules.

  3. Interaction of photosensitive surfactant with DNA and poly acrylic acid

    Science.gov (United States)

    Zakrevskyy, Yuriy; Cywinski, Piotr; Cywinska, Magdalena; Paasche, Jens; Lomadze, Nino; Reich, Oliver; Löhmannsröben, Hans-Gerd; Santer, Svetlana

    2014-01-01

    In this paper, we investigate interactions and phase transitions in polyelectrolyte-surfactant complexes formed between a cationic azobenzene-containing surfactant and two types of polyelectrolytes: natural (DNA) or synthetic (PAA: poly acrylic acid). The construction of a phase diagram allowed distancing between four major phases: extended coil conformation, colloidally stable compacted globules, colloidal instability range, and surfactant-stabilized compact state. Investigation on the complexes' properties in different phases and under irradiation with UV light provides information about the role of the surfactant's hydrophobic trans isomers both in the formation and destruction of DNA and PAA globules as well as in their colloidal stabilization. The trans isomer shows much stronger affinity to the polyelectrolytes than the hydrophilic cis counterpart. There is no need for complete compensation of the polyelectrolyte charges to reach the complete compaction. On contrary to the findings previously reported in the literature, we demonstrate - for the first time - complete polyelectrolyte compaction which occurs already at 20% of DNA (and at 50% of PAA) charge compensation. The trans isomer plays the main role in the compaction. The aggregation between azobenzene units in the photosensitive surfactant is a driving force of this process. The decompaction can be realized during UV light irradiation and is strongly influenced by the interplay between surfactant-surfactant and surfactant-DNA interactions in the compacted globules.

  4. Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

    Science.gov (United States)

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.

    2016-06-01

    Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

  5. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glyceryl-lacto esters of fatty acids. 172.852... HUMAN CONSUMPTION Multipurpose Additives § 172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and diglycerides) may be safely used in food...

  6. Fatty acid phytyl ester synthesis in chloroplasts of Arabidopsis.

    Science.gov (United States)

    Lippold, Felix; vom Dorp, Katharina; Abraham, Marion; Hölzl, Georg; Wewer, Vera; Yilmaz, Jenny Lindberg; Lager, Ida; Montandon, Cyrille; Besagni, Céline; Kessler, Felix; Stymne, Sten; Dörmann, Peter

    2012-05-01

    During stress or senescence, thylakoid membranes in chloroplasts are disintegrated, and chlorophyll and galactolipid are broken down, resulting in the accumulation of toxic intermediates, i.e., tetrapyrroles, free phytol, and free fatty acids. Chlorophyll degradation has been studied in detail, but the catabolic pathways for phytol and fatty acids remain unclear. A large proportion of phytol and fatty acids is converted into fatty acid phytyl esters and triacylglycerol during stress or senescence in chloroplasts. We isolated two genes (PHYTYL ESTER SYNTHASE1 [PES1] and PES2) of the esterase/lipase/thioesterase family of acyltransferases from Arabidopsis thaliana that are involved in fatty acid phytyl ester synthesis in chloroplasts. The two proteins are highly expressed during senescence and nitrogen deprivation. Heterologous expression in yeast revealed that PES1 and PES2 have phytyl ester synthesis and diacylglycerol acyltransferase activities. The enzymes show broad substrate specificities and can employ acyl-CoAs, acyl carrier proteins, and galactolipids as acyl donors. Double mutant plants (pes1 pes2) grow normally but show reduced phytyl ester and triacylglycerol accumulation. These results demonstrate that PES1 and PES2 are involved in the deposition of free phytol and free fatty acids in the form of phytyl esters in chloroplasts, a process involved in maintaining the integrity of the photosynthetic membrane during abiotic stress and senescence.

  7. Synthesis of Monomer Hydrogenated Rosin-Acrylic Glycerin Ester%氢化松香-丙烯酸丙三醇酯单体的合成

    Institute of Scientific and Technical Information of China (English)

    李浩; 王春平; 李鹏飞; 雷福厚; 段文贵

    2011-01-01

    Hydrogenated rosin-acrylic glycerin ester is synthesized from hydrogenated rosin modified by thionyl chloride obtained by reaction of hydrogenated rosin and thionyl chloride, glycerin and acryloyl chloride.Hydrogenated rosin acyl chloride is characterized by FTIR spectrum. Hydrogenated rosin glycerin ester obtained by reaction of hydrogenated rosin acyl chloride and glycerin is characterized by FTIR spectrum and determination of acid value, and its optimal synthetic reaction conditions are obtained as follows: molar ratio of hydrogenated rosinacyl chloride to glycerin is 1: 2. 5, pyridine as solvent, reaction time is 3 h, reaction temperature is ll0℃. The acid value of hydrogenated rosin glycerin ester is 21 mg·g-1 under above conditions. The structure of hydrogenated rosin-acrylic glycerin ester is confirmed by FTIR and UV-Vis. The monomer can polymerize in the presence of initiator. For the prepared polymer, its degree of cross linking is 75.1%, its solubility in aviation kerosene, carbinol, methylbenzene or cyclohexane is very small, and its softening point is 235℃.%以氢化松香、二氯亚砜、丙三醇、丙烯酰氯为主要原料,合成了可以均聚的氢化松香-丙烯酸丙三醇酯单体.氢化松香先与二氯亚砜反应制得氢化松香酰氯,通过FTIR对反应过程进行跟踪监测;氢化松香酰氯再与丙三醇经酯化反应合成氢化松香丙三醇酯,优化的反应条件为:吡啶作溶剂、n(氢化松香酰氯):n(丙三醇)=1:2.5、反应温度110℃、反应时间3 h,制得的氢化松香丙三醇酯酸值为21 mg·g-1;最后,氢化松香丙三醇酯与丙烯酰氯经酯化反应制得了氢化松香-丙烯酸丙三醇酯单体,通过FTIR和UV-Vis对其结构进行了表征.单体可以发生均聚反应,生成的颗粒状聚合物交联度为75.1%,在航空煤油、甲醇、甲苯、环己烷中的溶解度均很小,软化点为235℃.

  8. Dielectric Relaxation Properties of Alcohols and Acrylic Esters%醇与丙烯酸酯的介电弛豫性质

    Institute of Scientific and Technical Information of China (English)

    K.Dharmalingam; K.Ramachandran; P.Sivagurunathan; G.M.Kalamse

    2007-01-01

    Dielectric relaxation of alcohols (l-propanol, 1-butanol, sec-butanol, tert-butanol, 1-pentanol, 1-heptanol,1-octanol, and 1-decanol) with acrylic esters (methyl methacrylate, ethyl methacrylate, and butyl methacrylate) at 9.84 GHz were studied in n-heptane at 298 K. The result showed that 1:1 complex was predominant in these systems. The relaxation time showed a linear dependence with alkyl chain length of both alcohols and acrylic esters, but the dielectric constant showed a reverse trend. A comparative study of the free energy of activation for the dielectric relaxation and viscous flow suggested that a greater interference by neighboring atom was observed in the process of viscous flow than in dielectric relaxation, as the latter involved rotational form of motion, whereas the viscous flow involved both rotational and translational forms of motion.

  9. Preparation of Poly(acrylic acid Hydrogel by Radiation Crosslinking and Its Application for Mucoadhesives

    Directory of Open Access Journals (Sweden)

    Young-Chang Nho

    2014-03-01

    Full Text Available A mucoadhesive drug delivery system can improve the effectiveness of a drug by maintaining the drug concentration and allowing targeting and localization of the drug at a specific site. Acrylic-based hydrogels have been used extensively as a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, poly(acrylic acid was selected to prepare the bioadhesive hydrogel adhering to mucosal surfaces using a radiation process. Poly(acrylic acid was dissolved in water to a prepare poly(acrylic acid solution, and the solution was then irradiated by an electron beam at up to 75 kGy to make hydrogels. Their physical properties, such as gel percent, swelling percent and adhesive strength to mucosal surfaces, were investigated. Triamcinolone acetonide was used as a model drug. The dried poly(acrylic acid film was dipped in a 0.1 wt% triamcinolone acetonide solution in ethanol, and then dried at 25 °C. The release of triamcinolone acetonide was determined at different time intervals, and UV (Ultraviolet-Vis spectroscopy was used to determine the released concentration of triamcinolone acetonide at 238 nm. It was shown that poly(acrylic acid-based drug carriers were successfully prepared for use in a bioadhesive drug delivery system.

  10. A Convenient Synthesis of Amino Acid Methyl Esters

    Directory of Open Access Journals (Sweden)

    Yaowu Sha

    2008-05-01

    Full Text Available A series of amino acid methyl ester hydrochlorides were prepared in good toexcellent yields by the room temperature reaction of amino acids with methanol in thepresence of trimethylchlorosilane. This method is not only compatible with natural aminoacids, but also with other aromatic and aliphatic amino acids.

  11. Microwave-assisted preparation of naphthenic acid esters

    Directory of Open Access Journals (Sweden)

    VERA CIRIN-NOVTA

    2006-12-01

    Full Text Available The synthesis of esters of natural petroleum acids of the naphthenic type assisted with microwave irradiation under the conditions of acid catalysis was carried out with various alcohols: methanol, ethanol, n-butanol and tert-butyl alcohol. Microwave dielectric heating of the reaction mixture in an unmodified microwave oven with activation of the naphthenic acids with sulfuric and p-toluenesulfonic acid afforded the esters of the naphthenic acids. Depending on the catalyst and the steric and nucleophilic properties of the alcohols, the yield of naphthenic esters ranged from 31.25 % to 88.90 %. As a consequence of microwave dielectric heating, the esterification time was reduced from 6–10 h to 5 min.

  12. Supercritical water oxidation of acrylic acid production wastewater.

    Science.gov (United States)

    Gong, Y M; Wang, S Z; Tang, X Y; Xu, D H; Ma, H H

    2014-01-01

    Supercritical water oxidation (SCWO) of wastewater from an acrylic acid manufacturing plant has been studied on a continuous flow experimental system, whose reactor was made of Hastelloy C-276. Experimental conditions included a reaction temperature (T) ranging from 673 to 773K, a residence time (t) ranging from 72.7 to 339s, a constant pressure (P) of 25 MPa and a fixed oxidation coefficient (alpha) of 2.0. Experimental results indicated that reaction temperature and residence time had significant influences on the oxidation reaction, and increasing the two operation parameters could improve both degradation of chemical oxygen demand (COD) and ammonia nitrogen (NH3-N). The COD removal efficiency could reach up to 98.73% at 25 MPa, 773 K and 180.1 s, whereas the destruction efficiency of NH3-N was only 43.71%. We further carried out a kinetic analysis considering the induction period through free radical chain mechanism. It confirms that the power-law rate equation for COD removal was 345 exp(-52200/RT)[COD]1.98[O2]0.17 and for NH3-N removal was 500 exp(-64492.19/RT)[NH3-N]1.87 [O2]0.03. Moreover, the induction time formulations for COD and NH3-N were suspected to be exp(38250/RT)/173 and exp(55690/RT)/15231, respectively. Correspondingly, induction time changed from 2.22 to 5.38 s for COD and 0.38 to 1.38 s for NH3-N. Owing to the catalysis of reactor inner wall surface, more than 97% COD removal was achieved in all samples.

  13. Focal point analysis of torsional isomers of acrylic acid

    Science.gov (United States)

    Alev Çiftçioğlu, Gökçen; Trindle, Carl; Yavuz, Ilhan

    2010-10-01

    The thermochemistry of acrylic acid has presented challenges owing to its high reactivity, tendency to dimerize in the gas phase, and the existence of two very nearly equal energy conformational isomers. Well-tested thermochemical schemes including G2, G3, G4, and CBS-QB3 agree in the prediction that the s-cis syn structure is the most stable of the torsional isomers, with the s-cis anti form lying 3 kJ mol-1 or less higher in energy. Microwave spectra suggest a value of 0.63 kJ mol-1. The energy barrier between these forms is in the neighbourhood of 25 kJ mol-1 according to a MP2/cc-pVDZ calculation. We present estimates of the relative energies of all four torsional isomers and the rotational barrier based on a variant of the Focal Point Analysis developed by Császár and co-workers. These calculations, extending to the CCSD(T)/cc-pV5Z level, predict that the s-cis anti torsional isomer is the most stable form, in contrast to prior estimates. The s-cis syn form lies about 2.9 kJ mol-1 higher, while the s-trans syn and anti forms lie at about 21.7 and 23.3 kJ mol-1, respectively. We estimate the rotational barrier between the s-cis trans and s-cis anti structures to be about 23.9 kJ mol-1. Error ranges derived from the fit to extrapolation forms suggest that our estimates have an uncertainty of about 0.1 kJ mol-1.

  14. 21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Diacetyl tartaric acid esters of mono- and... acid esters of mono- and diglycerides. (a) Diacetyl tartaric acid esters of mono- and diglycerides, also know as DATEM, are composed of mixed esters of glycerin in which one or more of the...

  15. Polymorphism and polymerisation of acrylic and methacrylic acid at high pressure

    DEFF Research Database (Denmark)

    Oswald, Iain D. H.; Urquhart, Andrew J.

    2011-01-01

    The polymorphism and polymerisation of two related acids have been investigated under high pressure conditions. Acrylic acid crystallises as a new polymorph at 0.65 GPa whilst methacrylic acid crystallises in a new polymorph at a higher pressure of 1.5 GPa. Both these new polymorphs exhibit similar...

  16. Electrically conducting silver/guar gum/poly(acrylic acid) nanocomposite.

    Science.gov (United States)

    Abdel-Halim, E S; Al-Deyab, Salem S

    2014-08-01

    This article describes the synthesis of an electrically conducting silver/guar gum/poly(acrylic acid) nanocomposite hydrogel. The synthesis process started with grafting acrylic acid monomers onto the natural polymer guar gum by the use of ammonium persulphate as a free radical initiator in acid medium. Guar gum/poly(acrylic acid) graft copolymer was separated from the polymerization medium, purified and subjected to crosslinking treatment, using alkaline epichlorohydrin as a crosslinking agent. Silver nitrate solution was added during the crosslinking treatment in varying concentrations, that the reaction conditions affect crosslinking of guar gum/poly(acrylic acid) graft copolymer to a hydrogel, as well as reduction of silver nitrate to silver nanoparticles, giving rise to the formation of silver/guar gum/poly(acrylic acid) nanocomposite. Factors affecting the grafting reaction as well as those affecting the crosslinking/reduction treatment were optimized. The so synthesized nanocomposite hydrogel samples were fully characterized, regarding their contents of silver nanoparticles and swelling ratio. The electrical conductivity of the nanocomposite hydrogel was studied and it was found to be affected by the swelling ratio of the hydrogel as well as its content of silver nanoparticles.

  17. Sodium borohydride reduction of aromatic carboxylic acids via methyl esters

    Indian Academy of Sciences (India)

    Aamer Saeed; Zaman Ashraf

    2006-09-01

    A number of important aromatic carboxylic acids precursors, or intermediates in the syntheses of natural products, are converted into methyl esters and reduced to the corresponding primary alcohols using a sodium borohydride-THF-methanol system. The alcohols are obtained in 70-92% yields in 2-5 hours, in a pure state. This two-step procedure not only provides a better alternative to aluminum hydride reduction of acids but also allows the selective reduction of esters in presence of acids, amides, nitriles or nitro functions which are not affected under these conditions.

  18. Effects of high-melting methyl esters on crystallization properties of fatty acid methyl ester mixtures

    Science.gov (United States)

    Biodiesel is a renewable alternative diesel fuel made from vegetable oils and animal fats. The most common form of biodiesel in the United States are fatty acid methyl esters (FAME) from soybean, canola, and used cooking oils, waste greases, and tallow. Cold flow properties of biodiesel depend on th...

  19. Synthesis of fatty acid starch esters in supercritical carbon dioxide

    NARCIS (Netherlands)

    Muljana, Henky; van der Knoop, Sjoerd; Keijzer, Danielle; Picchioni, Francesco; Janssen, Leon P. B. M.; Heeres, Hero J.

    2010-01-01

    This manuscript describes an exploratory study on the synthesis of fatty acid/potato starch esters using supercritical carbon dioxide (scCO(2)) as the solvent. The effects of process variables such as pressure (6-25 MPa), temperature (120-150 degrees C) and various basic catalysts and fatty acid der

  20. 76 FR 41135 - 2-Propenoic acid, 2-methyl-, phenylmethyl ester, polymer with 2-propenoic acid and sodium 2...

    Science.gov (United States)

    2011-07-13

    ... AGENCY 40 CFR Part 180 2-Propenoic acid, 2-methyl-, phenylmethyl ester, polymer with 2- propenoic acid...-Propenoic acid, 2-methyl-, phenylmethyl ester, polymer with 2-propenoic acid and sodium 2-methyl- 2- -1... for residues of 2-Propenoic acid, 2-methyl-,phenylmethyl ester, polymer with 2-propenoic acid...

  1. Synthesis of radiation crosslinked poly(acrylic acid) in the presence of phenyltriethoxysilane

    Science.gov (United States)

    Hassan, Safia; Yasin, Tariq

    2014-04-01

    Acrylic acid based superabsorbent hydrogel was prepared using phenyltriethoxysilane (PTES) as polyfunctional monomer. Different amounts of PTES were incorporated in acrylic acid and irradiated at different doses upto maximum of 30 kGy. The crosslinked acrylic acid showed hydrogel properties and its swelling kinetics, gel fraction and equilibrium degree of swelling (EDS) were studied. It was found that the increased PTES concentration decreased the EDS of the hydrogels. Infrared spectroscopy confirmed the crosslinking reaction between the feed components and the existence of siloxane bond. Thermogravimetric analysis showed an increase in the stability of the hydrogels having high PTES content. The swelling of the hydrogel was affected by pH, ionic strength and temperature. These hydrogels showed low swelling in acidic and basic pH range and high swelling around neutral pH. This switchable pH response of these hydrogels can be exploited in environmental and biomedical applications.

  2. Surface modification of cellulosic substrates via atmospheric pressure plasma polymerization of acrylic acid: Structure and properties

    Science.gov (United States)

    Garcia-Torres, Jose; Sylla, Dioulde; Molina, Laura; Crespo, Eulalia; Mota, Jordi; Bautista, Llorenç

    2014-06-01

    Surface chemical modification of cellulose-based substrates has been carried out by atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD) of acrylic acid. The structure/properties relationship of the samples was studied as a function of the plasma experimental conditions. Acrylic acid monomer/helium ratio and treatment speed clearly influences the wettability properties of the paper substrate: advancing contact angle values were reduced to the half if compare to non-treated paper. Surface morphology of the films did not greatly vary at short polymerization times but fibers were covered by a poly(acrylic acid) film at longer times. FTIR and XPS techniques allowed detecting the retention of carboxylic acid groups/moieties. The possibility to quickly design architectures with tunable carboxylic functions by modifying the plasma processing parameters is shown.

  3. Covalent Functionalization of Multiwalled Carbon Nanotubes with Poly(acrylic acid)

    Institute of Scientific and Technical Information of China (English)

    LIU, Yan-Xin; DU, Zhong-Jie; LI, Yan; ZHANG, Chen; LI, Hang-Quan

    2006-01-01

    Covalent functionalization of multiwalled carbon nanotubes (MWNT) with poly(acrylic acid) has been successfully achieved via grafting of poly(acryloyl chloride) on nanotube surface by esterification reaction of acyl chloride-bound polymer with hydroxyl functional groups present on acid-oxidized MWNT and hydrolysis of polymer attached to nanotubes. Polymer-functionalized MWNT could possess remarkably high solubility in water, and their aqueous solution was very stable without any observable black deposit for a long time. Characterizations of such functionalized MWNT samples using Fourier transform infrared spectrometer, transmission electron microscopy and nuclear magnetic resonance techniques indicated that poly(acrylic acid) was covalently attached to the surface of MWNT.

  4. Glycerol oxidehydration into acrolein and acrylic acid over W/V/Nb bronzes with hexagonal structure

    Energy Technology Data Exchange (ETDEWEB)

    Basile, F.; Cavani, F.; Chieregato, A. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali; CIRI Energia e Ambiente, Bologna (Italy); Concepcion, P.; Lopez Nieto, J.M.; Soriano, M.D. [Univ. Politecnica de Valencia (Spain). Inst. de Tecnologia Quimica; Liosi, G.; Trevisanut, C. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali

    2012-07-01

    This paper deals with an investigation of hexagonal W-V-Nb-O and W-V-Mo-O bronzes as catalysts for the one-pot oxidehydration of glycerol into acrylic acid. In a previous work, we reported a study on a bi-component bronze W-V-O that allowed us to obtain a 25% acrylic acid selectivity; in the current work, the incorporation of either Nb or Mo in a tri-component bronze structure allowed us to tune the acid and redox properties of the catalyst, so as to study their influence on the overall reaction scheme. (orig.)

  5. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactylated fatty acid esters of glycerol and... esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and... additive is a mixture of esters produced by the lactylation of a product obtained by reacting edible...

  6. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

    2016-06-14

    Methods and systems for making dibasic esters and/or dibasic acids using metathesis are generally disclosed. In some embodiments, the methods comprise reacting a terminal olefin ester with an internal olefin ester in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In some embodiments, the terminal olefin ester or the internal olefin ester are derived from a renewable feedstock, such as a natural oil feedstock. In some such embodiments, the natural oil feedstock, or a transesterified derivative thereof, is metathesized to make the terminal olefin ester or the internal olefin ester.

  7. Synthesis of a novel acrylated abietic acid-g-bacterial cellulose hydrogel by gamma irradiation.

    Science.gov (United States)

    Abeer, Muhammad Mustafa; Amin, Mohd Cairul Iqbal Mohd; Lazim, Azwan Mat; Pandey, Manisha; Martin, Claire

    2014-09-22

    Acrylated abietic acid (acrylated AbA) and acrylated abietic acid-grafted bacterial cellulose pH sensitive hydrogel (acrylated AbA-g-BC) were prepared by a one-pot synthesis. The successful dimerization of acrylic acid (AA) and abietic acid (AbA) and grafting of the dimer onto bacterial cellulose (BC) was confirmed by 13C solid state NMR as well as FT-IR. X-ray diffraction analysis showed characteristic peaks for AbA and BC; further, there was no effect of increasing amorphous AA content on the overall crystallinity of the hydrogel. Differential scanning calorimetry revealed a glass transition temperature of 80°C. Gel fraction and swelling studies gave insight into the features of the hydrogel, suggesting that it was suitable for future applications such as drug delivery. Scanning electron microscopy observations showed an interesting interpenetrating network within the walls of hydrogel samples with the lowest levels of AA and gamma radiation doses. Cell viability test revealed that the synthesized hydrogel is safe for future use in biomedical applications.

  8. Direct Synthesis of Hyperbranched Poly(acrylic acid-co-3-hydroxypropionate

    Directory of Open Access Journals (Sweden)

    Efkan Çatıker

    2015-01-01

    Full Text Available Hyperbranched poly(acrylic acid-co-3-hydroxypropionate (PAcHP was synthesized by base-catalyzed hydrogen transfer polymerization of acrylic acid through one step. The copolymers obtained through solution and bulk polymerization were insoluble in water and all organic solvents tried. Structural and compositional characterizations of hyperbranched PAcHP were performed by using FTIR, solid 13C-NMR, TGA, and titrimetric analysis. Acrylate fraction of the hyperbranched PAcHP obtained via bulk polymerization was determined as 60–65% by comparing TGA curves of hyperbranched PAcHP and pure poly(3-hydroxy propionate (PHP. However, analytical titration of the same sample revealed that acrylic acid units were about 47.3%. The results obtained from TGA and analytical titration were used to evaluate the chemical structure of the copolymer. Hyperbranched PAcHP exhibited hydrogel properties. Swelling behavior of the copolymer was investigated at a wide pH range and ionic strength. The dynamic swelling profiles of hyperbranched PAcHP exhibited a fast swelling behavior in the first hour and achieved the equilibrium state within 12 h in PBS. Depending on the conditions, the copolymers exhibited swelling ratios up to 2100%. As the copolymer has easily biodegradable propionate and versatile functional acrylic acid units, it can be used as not only biodegradable material in medical applications but also raw material in personal care commodities.

  9. Radiation synthesis of superabsorbent poly(acrylic acid)-carrageenan hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Sanju; Kumar, Manmohan; Varshney, Lalit E-mail: lalitv@magnum.barc.ernet.in

    2004-04-01

    A series of superabsorbent hydrogels were prepared from carrageenan and partially neutralized acrylic acid by gamma irradiation at room temperature. The gel fraction, swelling kinetics and the equilibrium degree of swelling (EDS) of the hydrogels were studied. It was found that the incorporation of even 1% carrageenan (sodium salt) increases the EDS of the hydrogels from {approx}320 to {approx}800 g/g. Thermal analysis were carried out to determine the amount of free water and bound water in the hydrogels. Under optimum conditions, poly(acrylic acid)-carrageenan hydrogels with high gel fraction ({approx}80%) and very high EDS ({approx}800 g/g) were prepared gamma radiolytically from aqueous solution containing 15% partially neutralized acrylic acid and 1-5% carrageenan. The hydrogels were also found to be sensitive to the pH and the ionic strength of the medium.

  10. Effect of preparation conditions on selective oxidation of propane to acrylic acid

    Institute of Scientific and Technical Information of China (English)

    YU Zhen-xing; ZHENG Wei; XU Wen-long; ZHANG Yu-hang; FU Hong-ying; ZHANG Ping

    2009-01-01

    The effects of chemical composition and preparation conditions, especially calcination atmosphere and water content on the catalytic performances of MoVTeNbO mixed oxide catalyst system for the selective oxidation of propane to acrylic acid were investigated. Among the catalysts studied, MO_(1.0)V_(0.3)Te_(0.23)Nb_(0.12)O_x catalyst calcined in inert atmosphere at 600 ℃ shows the best performance in terms of propane conversion and selectivity to acrylic acid. The results reveal that proper chemical composition, calcination atmosphere and water content affect greatly the catalysts in many ways including structure, chemical composition, which are related to their catalytic performances; and 51.0% propane conversion and 30.5% one-pass yield to acrylic acid can be achieved at the same time.

  11. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Science.gov (United States)

    2010-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  12. Synthesis of Acrylic Acid/Kaoline Powder Superabsorbent Composite by Inverse-suspending Polymerization

    Institute of Scientific and Technical Information of China (English)

    ZHONG Jin-feng; XUE Yi-ming; WU Ji-huai; LIN Jian-ming; WEI Yue-lin

    2004-01-01

    An acrylic acid/kaoline powder superabsorbent composite with a water absorbency of the superabsorbent composite about 1/800 was synthesized by inverse-suspending polymerization reaction between acrylic acid monomer and kaoline ultrafine powder. The influence of the dispersant agent on the configuration of the products in the inverse suspension polymerization is investigated. The influences of the kaoline powder, cross-linker, initiator, neutralization degree and the volume ratio of oil to water phase on the water absorbency of the superabsorbent composites are discussed in the paper.

  13. Synthesis of poly(N-isopropylacrylamide-co-acrylic acid) model compounds for filtration experiments

    DEFF Research Database (Denmark)

    Hinge, Mogens; Christensen, Morten Lykkegaard; Scales, Peter

    2005-01-01

    these biosolid/organic systems and thereby make a basis for further theoretical development with respect to filtration.   Poly(N-isopropylacrylamide-co-acrylic acid) microgels are synthesized by free-radical surfactant free emulsion polymerization as an organic model system for biosolids. The model system...... concentrations of acrylic acid as co-monomer. The microgels have a charge density between 0.2 and 0.9 mmol/g.   Preliminary filtration experiments show that filtration properties of the microgel model system significantly differs from the properties for inorganic colloidals such as titaniumdioxid....

  14. Graft Copolymerization of Acrylic Acid onto Fungal Cell Wall Structural Polysaccharide

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Acrylic acid was graft-copolymerized onto Rhi. oryzae's cell wall structural polysacchaxide directly and efficiently in aqueous solution with ceric ammonium nitrate as initiator. The maximal grafting percentage of 135.5% was obtained under the condition of [Ce4+]=5mmol.L-1, [AA]=1mol.L-1, T=60°C and t=3h. Graft copolymerization was suggested to proceed through free radical reaction mechanism. Grafting occurred primarily on chitosan. Acrylic acid was also attempted to be grafted onto Asp. niger cell wall structural polysaccharide, and only 44.2% of grafting percentage was resulted.

  15. Synthesis and characterization of poly acrylic acid/graphite oxide nanocomposite

    Institute of Scientific and Technical Information of China (English)

    胡源; 丁溶芳; 徐加艳; 王清安; 陈祖耀; 范维澄

    2003-01-01

    Acrylic acid-intercalated graphite oxide and poly acrylic acid (PAA)-intercalated graphite oxide were prepared and characterized by X-Ray diffraction (XRD), Fourier transform infrared spectra (FTIR) and high resolution electronic microscope (HREM). Results show that the intercalation process is not only a physical diffusion process but also mainly a chemical reaction process. The high resolution electronic microscope results also reveal that the Ic value of PAA-intercalated graphite oxide (GO) could change widely from 1.6nm to 4.0nm.

  16. Electroactive behavior assessment of poly(acrylic acid)-graphene oxide composite hydrogel in the detection of cadmium

    NARCIS (Netherlands)

    Bejarano-Jimenez, A.; Escobar-Barrios, V.A.; Kleijn, J.M.; Oritz-Ledon, C.A.; Chazaro-Ruiz, L.F.

    2014-01-01

    Super absorbent polymers of acrylic acid-graphene oxide (PAA-GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous

  17. SYNTHESIS OF 2—HYDROXYETHYL ACRYLATE BY USING STRONG ACIDIC CATION ION EXCHANGE RESIN AS CATALYST

    Institute of Scientific and Technical Information of China (English)

    GAODabin

    1992-01-01

    2-Hydroxyethyl acrylate is synthesized from acrylic acid and ethylene glycol under a simple and mild condition by using strong acidic cation ion exchange resin as a catalyst,which could be recycled as long as 10 times with high activation.

  18. Thin film of Poly(acrylic acid-co-allyl acrylate as a Sacrificial Protective Layer for Hydrophilic Self Cleaning Glass

    Directory of Open Access Journals (Sweden)

    Jānis Lejnieks

    2010-05-01

    Full Text Available Poly(acrylic acid-co-allyl acrylate statistical copolymers were synthesized in a controlled manner in two steps: first tert.butyl acrylate and allyl acrylate were polymerized via atom transfer radical polymerization (ATRP and afterwords the tert.butyl protective groups were removed via hydrolysis. Samples of self cleaning glass (SCG were coated with thin films of poly(acrylic acid-co-allyl acrylate and cross-linked afterwards by UV irradiation (in the presence of a photoinitiator and an accelerator. Solution cast thin films were transparent and homogeneous before and after UV cross-linking. The irradiated samples were found to be hydrophilic (Θ < 20° and water insoluble. The coating prevented the spontaneous hydrophobization of the SCG by residual silicon exhaled from the sealing material. The TiO2 photocatalyst that covers the glass surface was found to strip the protective coating. The rate of the photooxidation process was measured by IR spectroscopy. The real field performance of the protective coating was also tested.

  19. In vitro pharmacokinetics of anti-psoriatic fumaric acid esters

    NARCIS (Netherlands)

    N.H.R. Litjens (Nicolle); E. van Strijen (Elizabeth); C. van Gulpen (Co); H. Mattie (Herman); J.T. van Dissel (Jaap); H.B. Thio (Bing); P.H. Nibbering (Peter)

    2004-01-01

    textabstractBackground: Psoriasis is a chronic inflammatory skin disease that can be successfully treated with a mixture of fumaric acid esters (FAE) formulated as enteric-coated tablets for oral use. These tablets consist of dimethylfumarate (DMF) and salts of monoethylfumarate (MEF) and its main b

  20. Synthesis and insecticidal activities of new pyrethroid acid oxime ester derivatives

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A series of compounds containing oxime-ester linkage in place of the ester linkage in pyrethroid ester are designed and prepared. Bioassay data of insecticidal activities of these compounds on Ostrinia nubilalis (H.) and Culex pipines (L.) are presented. Among them 4-dimethyaminobenzaldehyde oxime ester of 2,2,3,3-tetramethylcyclopropanecarboxylic acid and 4-dimethyamino benzaldehyde oxime ester of cyclopropanecarboxylic acid are found to be potent insecticide against Ostrinia nubilalis (H.). Structure-activity relationship of the compounds is discussed.

  1. 76 FR 7703 - 1,4-Benzenedicarboxylic Acid, Dimethyl Ester, Polymer With 1,4-Butanediol, Adipic Acid, and...

    Science.gov (United States)

    2011-02-11

    ... AGENCY 40 CFR Part 180 1,4-Benzenedicarboxylic Acid, Dimethyl Ester, Polymer With 1,4- Butanediol, Adipic... from the requirement of a tolerance for residues of 1,4-benzenedicarboxylic acid, dimethyl ester... residues of 1,4-benzenedicarboxylic acid, dimethyl ester, polymer with 1,4-butanediol, adipic acid,...

  2. Effect of Grafted Hydroquinone on the Acid-Base Properties of Poly(acrylic acid) in the Presence of Copper (II)

    OpenAIRE

    Nabila Bensacia; Saâd Moulay; François Garin; Ioana Fechete; Anne Boos

    2015-01-01

    Potentiometric titration of poly(acrylic acid) and hydroquinone-functionalized poly(acrylic acid) was conducted in the presence of copper (II). The effects of hydroquinone functionalizing and copper (II) complexing on the potentiometric titration of poly(acrylic acid) were studied in an ionic environment and in its absence. Henderson-Hasselbalch equation was applied to assess its validity for this titration. Coordination number and the stability constants of the copper- (II-)complexed polymer...

  3. Fatty acid methyl esters production: chemical process variables

    Directory of Open Access Journals (Sweden)

    Paulo César Narváez Rincón

    2010-06-01

    Full Text Available The advantages of fatty acid methyl esters as basic oleochemicals over fatty acids, the seventies world energy crisis and the use of those oleochemicals as fuels, have increased research interest on fats and oils trans-esterification. In this document, a review about basic aspects, uses, process variables and problems associated to the production process of fatty acid methyl esters is presented. A global view of recent researches, most of them focused in finding a new catalyst with same activity as the alcohol-soluble hydroxides (NaOH, KOH, and suitable to be used in transforming fats and oils with high levels of free fatty acids and water avoiding separation problems and reducing process costs, is also discussed.

  4. Transferable force field for carboxylate esters: application to fatty acid methylic ester phase equilibria prediction.

    Science.gov (United States)

    Ferrando, Nicolas; Lachet, Véronique; Boutin, Anne

    2012-03-15

    In this work, a new transferable united-atoms force field for carboxylate esters is proposed. All Lennard-Jones parameters are reused from previous parametrizations of the AUA4 force field, and only a unique set of partial electrostatic charges is introduced for the ester chemical function. Various short alkyl-chain esters (methyl acetate, ethyl acetate, methyl propionate, ethyl propionate) and two fatty acid methylic esters (methyl oleate and methyl palmitate) are studied. Using this new force field in Monte Carlo simulations, we show that various pure compound properties are accurately predicted: saturated liquid densities, vapor pressures, vaporization enthalpies, critical properties, liquid-vapor surface tensions. Furthermore, a good accuracy is also obtained in the prediction of binary mixture pressure-composition diagrams, without introducing empirical binary interaction parameters. This highlights the transferability of the proposed force field and gives the opportunity to simulate mixtures of industrial interest: a demonstration is performed through the simulation of the methyl oleate + methanol mixture involved in the purification sections of biodiesel production processes.

  5. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E; Cohen, Steven A; Gildon, Demond L

    2015-04-07

    Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

  6. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

    2016-03-15

    Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

  7. Encapsulating fatty acid esters of bioactive compounds in starch

    Science.gov (United States)

    Lay Ma, Ursula Vanesa

    Interest in the use of many bioactive compounds in foods is growing in large part because of the apparent health benefits of these molecules. However, many of these compounds can be easily degraded during processing, storage, or their passage through the gastrointestinal tract before reaching the target site. In addition, they can be bitter, acrid, or astringent, which may negatively affect the sensory properties of the product. Encapsulation of these molecules may increase their stability during processing, storage, and in the gastrointestinal tract, while providing controlled release properties. The ability of amylose to form inclusion complexes and spherulites while entrapping certain compounds has been suggested as a potential method for encapsulation of certain molecules. However, complex formation and spherulitic crystallization are greatly affected by the type of inclusion molecules, type of starch, and processing conditions. The objectives of the present investigation were to: (a) study the effect of amylose, amylopectin, and intermediate material on spherulite formation and its microstructure; (b) investigate the formation of amylose and high amylose starch inclusion complexes with ascorbyl palmitate, retinyl palmitate, and phytosterol esters; (c) evaluate the ability of spherulites to form in the presence of fatty acid esters and to entrap ascorbyl palmitate, retinyl palmitate, and phytosterol esters; and (d) evaluate the effect of processing conditions on spherulite formation and fatty acid ester entrapment. Higher ratios of linear to branched molecules resulted in the formation of more and rounder spherulites with higher heat stability. In addition to the presence of branches, it appears that spherulitic crystallization is also affected by other factors, such as degree of branching, chain length, and chain length distribution. Amylose and Hylon VII starch formed inclusion complexes with fatty acid esters of ascorbic acid, retinol, or phytosterols

  8. 40 CFR 721.8340 - Mono esters from 2- propenoic acid (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mono esters from 2- propenoic acid... Specific Chemical Substances § 721.8340 Mono esters from 2- propenoic acid (generic). (a) Chemical... as mono esters from 2-propenoic acid (PMN P-01-85) is subject to reporting under this section for...

  9. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl polycarboxylic acids, esters... Significant New Uses for Specific Chemical Substances § 721.6475 Alkyl polycarboxylic acids, esters with... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated...

  10. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Partial phosphoric acid esters of polyester resins... COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this...

  11. 40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.

    Science.gov (United States)

    2010-07-01

    ...) derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection of Environment...) derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant new uses subject...) derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to reporting under this...

  12. 21 CFR 573.640 - Methyl esters of higher fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Methyl esters of higher fatty acids. 573.640... ANIMALS Food Additive Listing § 573.640 Methyl esters of higher fatty acids. The food additive methyl esters of higher fatty acids may be safely used in animal feeds in accordance with the...

  13. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acid, ester with styrenated... Significant New Uses for Specific Chemical Substances § 721.3700 Fatty acid, ester with styrenated phenol... chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene...

  14. 40 CFR 721.2900 - Substituted aminobenzoic acid ester (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted aminobenzoic acid ester... Specific Chemical Substances § 721.2900 Substituted aminobenzoic acid ester (generic name). (a) Chemical... acid ester (PMN P-84-951) is subject to reporting under this section for the significant new...

  15. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    Science.gov (United States)

    2010-07-01

    ... polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol,...

  16. 75 FR 52269 - Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption

    Science.gov (United States)

    2010-08-25

    ...-2010-0429; FRL-8841-2] Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of acetic acid ethenyl ester, polymer with oxirane... permissible level for residues of acetic acid ethenyl ester, polymer with oxirane on food or feed...

  17. 40 CFR 721.4250 - Hexanoic acid, 2-ethyl-, ethenyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexanoic acid, 2-ethyl-, ethenyl ester... Substances § 721.4250 Hexanoic acid, 2-ethyl-, ethenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, ethenyl ester...

  18. 78 FR 70878 - Octadecanoic Acid, 12-Hydroxy-, Homopolymer, Ester With 2-Methyloxirane Polymer With Oxirane...

    Science.gov (United States)

    2013-11-27

    ... AGENCY 40 CFR Part 180 Octadecanoic Acid, 12-Hydroxy-, Homopolymer, Ester With 2- Methyloxirane Polymer... residues of Octadecanoic Acid, 12-Hydroxy-, Homopolymer, Ester with 2-Methyloxirane Polymer with Oxirane... a maximum permissible level for residues of Octadecanoic Acid, 12-Hydroxy-, Homopolymer, Ester...

  19. 40 CFR 721.10064 - 2-Propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 2-Propenoic acid, 2- ethyl ester. 721... Substances § 721.10064 2-Propenoic acid, 2- ethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2- ethyl ester (PMN...

  20. Synthesis and antibacterial properties of beta-diketone acrylate bioisosteres of pseudomonic acid A.

    Science.gov (United States)

    Bennett, I; Broom, N J; Cassels, R; Elder, J S; Masson, N D; O'Hanlon, P J

    1999-07-05

    A series of beta-diketone acrylate bioisosteres 4 of pseudomonic acid A 1 have been synthesized and evaluated for their ability to inhibit bacterial isoleucyl-tRNA synthetase and act as antibacterial agents. A number of analogues have excellent antibacterial activity. Selected examples were shown to afford good blood levels and to be effective in a murine infection model.

  1. Selective oxidation of propane to acrylic acid over mixed metal oxide catalysts

    Institute of Scientific and Technical Information of China (English)

    Wei Zheng; Zhenxing Yu; Ping Zhang; Yuhang Zhang; Hongying Fu; Xiaoli Zhang; Qiquan Sun; Xinguo Hu

    2008-01-01

    The effects of metal atomic ratio, water content, oxygen content, and calcination temperature on the catalytic perfor-mances of MoVTeNbO mixed oxide catalyst system for the selective oxidation of propane to acrylic acid have been investigated and discussed. Among the catalysts studied, it was found that the MoVTeNbO catalyst calcined at a temperature of 600 ℃ showed the best performance in terms of propane conversion and selectivity for acrylic acid under an atmosphere of nitrogen. An effective MoVTeNbO oxide catalyst for propane selective oxidation to acrylic acid was obtained with a combination of a preferred metal atomic ratio (Mo1 V0.31Te0.23Nb0.12). The optimum reaction condition for the selective oxidation of propane was the molar ratio of C3H81 :O2 : H2O : N1 = 4.4 : 12.8 : 15.3 : 36.9. Under such conditions, the conversion of propane and the maximum yield of acrylic acid reached about 50% and 21%, respectively.

  2. Gold Nanoparticles Protected with Thiol-Derivatized Amphiphilic Poly(epsilon-caprolactone)-b-poly(acrylic acid)

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Hvilsted, Søren

    2009-01-01

    Amphiphilic poly(epsilon-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) with a thiol functionality in the PCL terminal has been prepared in a novel synthetic cascade. Initially, living anionic ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) employing the difunctional...

  3. Development of nanoparticulate drug delivery systems based on thiolated poly(acrylic acid).

    Science.gov (United States)

    Thaurer, Michael H; Deutel, Britta; Schlocker, Wolfgang; Bernkop-Schnürch, Andreas

    2009-05-01

    In this study the preparation and stabilization of poly(acrylic acid)-cysteine nanoparticles and incorporation of a fluorescence marked model-compound was investigated. Nanoparticles were prepared by ionic gelation of a poly(acrylic acid)-cysteine conjugate with calcium chloride. Poly(acrylic acid)-cysteine nanoparticles display high cohesive properties due to a cross-linking process via calcium bridges in the core and the pervasive formation of disulphide bonds and were 139 ± 34 nm in size. Nanoparticles were loaded with FITC-dextrans (flourescein isothiocyanate-dextrans) of 4, 20 and 40 kDa molecular mass as model-compound via sonication method or via vibration method for 3 and 24 h. In vitro release studies showed an initial burst release followed by an extended release of model-compounds. The lower the molecular mass of the FITC-dextrans, the higher was the amount of incorporated and released model compounds. Vibration seems to be a proper method for the incorporation of hydrophilic and macromolecular drugs in poly(acrylic acid)-cysteine nanoparticles.

  4. Green Synthesis of Acid Esters from Furfural via Stobbe Condensation

    Directory of Open Access Journals (Sweden)

    Shubhra Banerjee

    2013-01-01

    Full Text Available Solvent-free Stobbe condensation of furfural 1 with dimethyl succinate 2 under anhydrous conditions at room temperature using dry-solid potassium tertiary butoxide gave 3-carbomethoxy, 4-furyl-3-butenoic acid 3, which upon methylation followed by Stobbe condensation reaction with different aldehydes and/or ketones under anhydrous conditions at room temperature afforded substituted carbomethoxy acids 5a–f. These acid ester products were saponified to the corresponding dicarboxylic acids 6a–f which are useful in the synthesis of photochromic fulgides.

  5. Cisplatin-incorporated nanoparticles of poly(acrylic acid-co-methyl methacrylate copolymer

    Directory of Open Access Journals (Sweden)

    Lee KD

    2013-08-01

    Full Text Available Kyung Dong Lee,1,* Young-Il Jeong,2,* Da Hye Kim,3,4 Gyun-Taek Lim,2 Ki-Choon Choi5 1Department of Oriental Medicine Materials, Dongshin University, Naju, South Korea; 2Department of Polymer Engineering, Chonnam National University, Gwangju, South Korea; 3Faculty of Life and Environmental Science, Shimane University, Matsue, Japan; 4United Graduate School of Agricultural Sciences, Tottori University, Tottori, Japan; 5Grassland and Forages Division, National Institute of Animal Science, Rural Development Administration, Cheonan, South Korea *These authors contributed equally to this work Background: Although cisplatin is extensively used in the clinical field, its intrinsic toxicity limits its clinical use. We investigated nanoparticle formations of poly(acrylic acid-co-methyl methacrylate (PAA-MMA incorporating cisplatin and their antitumor activity in vitro and in vivo. Methods: Cisplatin-incorporated nanoparticles were prepared through the ion-complex formation between acrylic acid and cisplatin. The anticancer activity of cisplatin-incorporated nanoparticles was assessed with CT26 colorectal carcinoma cells. Results: Cisplatin-incorporated nanoparticles have small particle sizes of less than 200 nm with spherical shapes. Drug content was increased according to the increase of the feeding amount of cisplatin and acrylic acid content in the copolymer. The higher acrylic acid content in the copolymer induced increase of particle size and decrease of zeta potential. Cisplatin-incorporated nanoparticles showed a similar growth-inhibitory effect against CT26 tumor cells in vitro. However, cisplatin-incorporated nanoparticles showed improved antitumor activity against an animal tumor xenograft model. Conclusion: We suggest that PAA-MMA nanoparticles incorporating cisplatin are promising carriers for an antitumor drug-delivery system. Keywords: cisplatin, nanoparticle, poly(acrylic acid-co-methyl methacrylate, ion complexes

  6. Injectable biocompatible and biodegradable pH-responsive hollow particle gels containing poly(acrylic acid): the effect of copolymer composition on gel properties.

    Science.gov (United States)

    Halacheva, Silvia S; Adlam, Daman J; Hendow, Eseelle K; Freemont, Tony J; Hoyland, Judith; Saunders, Brian R

    2014-05-12

    The potential of various pH-responsive alkyl (meth)acrylate ester- and (meth)acrylic acid-based copolymers, including poly(methyl methacrylate-co-acrylic acid) (PMMA-AA) and poly(n-butyl acrylate-co-methacrylic acid) (PBA-MAA), to form pH-sensitive biocompatible and biodegradable hollow particle gel scaffolds for use in non-load-bearing soft tissue regeneration have been explored. The optimal copolymer design criteria for preparation of these materials have been established. Physical gels which are both pH- and redox-sensitive were formed only from PMMA-AA copolymers. MMA is the optimal hydrophobic monomer, whereas the use of various COOH-containing monomers, e.g., MAA and AA, will always induce a pH-triggered physical gelation. The PMMA-AA gels were prepared at physiological pH range from concentrated dispersions of swollen, hollow, polymer-based particles cross-linked with either cystamine (CYS) or 3,3'-dithiodipropionic acid dihydrazide (DTP). A linear relationship between particle swelling ratios, gel elasticity, and ductility was observed. The PMMA-AA gels with lower AA contents feature lower swelling ratios, mechanical strengths, and ductilities. Increasing the swelling ratio (e.g., through increasing AA content) decreased the intraparticle elasticity; however, intershell contact and gel elasticity were found to increase. The mechanical properties and performance of the gels were tuneable upon varying the copolymers' compositions and the structure of the cross-linker. Compared to PMMA-AA/CYS, the PMMA-AA/DTP gels were more elastic and ductile. The biodegradability and cytotoxicity of the new hollow particle gels were tested for the first time and related to their composition, mechanical properties, and morphology. The new PMMA-AA/CYS and PMMA-AA/DTP gels have shown good biocompatibility, biodegradability, strength, and interconnected porosity and therefore have good potential as a tissue repair agent.

  7. Eco-friendly Crosslinking Agent for Acid Functional Acrylic Resin

    Directory of Open Access Journals (Sweden)

    Archana Shah

    2009-01-01

    Full Text Available Oil from J. multifida was extracted and it was first converted into N,N-bis(2-hydroxyethyl Jatropha fatty amide (HEJFA. HEJFA has been synthesized by reaction between Jatropha oil and diethanol amine in presence of zinc oxide as a catalyst. The reaction is relatively rapid and proceeded to high yield at 200±5 OC. The resulting HEJFA was used to formulate thermosetting coating compositions. Films were cured at ambient (air drying and elevated (stove drying temperatures using N, N-bis(2-hydroxyethyl Jatropha fatty amide (HEJFA as eco-friendly crosslinking agent for acrylic resin. The coating performance of the various compositions was tested by measurement of scratch hardness, impact strength and chemical resistance. The results show better performance of the HEJFA based compositions compared to butylated melamine formaldehyde (MF based compositions.

  8. Synthesis of dense poly(acrylic acid) brushes and their interaction with amine-functional silsesquioxane nanoparticles

    NARCIS (Netherlands)

    Retsch, Markus; Walther, Andreas; Loos, Katja; Mueller, Axel H. E.; Müller, Axel H.E.

    2008-01-01

    Poly(acrylic acid) polyetectrolyte brushes were synthesized by surface-initiated atom transfer radical polymerization (SI-ATRP) of tert-butyl acrylate on planar gold surfaces and subsequent hydrolysis. Three types of monolayers with different numbers of thiol binding sites per initiating unit were u

  9. Modification of polyethylene by radiation-induced graft polymerization of acrylic acid

    Science.gov (United States)

    Sidorova, L. P.; Aliev, A. D.; Zlobin, V. B.; Aliev, R. E.; Chalykh, A. E.; Kabanov, V. Ya.

    The kinetics investigation of the radiation-induced graft polymerization of acrylic acid onto low density polyethylene by direct method in aqueous solution in the presence of Mohr's salt, was performed. The technique of the contrasting of polyacrylic acid (PAA) graft layer was worked out by Ag +-ions. The structural and morphological peculiarities of grafted copolymers of PE with PAA were determined by the method of electron probe, and X-ray microanalysis by means of the electron microscopy.

  10. CHARACTERIZATION OF RADIATION GRAFTING DEGREE OF POLYSTYRENE g-ACRYLIC ACID BY XPS

    Institute of Scientific and Technical Information of China (English)

    CHE Jitai; ZHANG Wanxi

    1990-01-01

    It this work, characterization of radiation grafting degree of polystyrene-g-acrylic acid by XPS was studied. It is found that along with the main peak C1s there is a photoelectron peak at 289.0 eV that appears to be C1s of -C(=O)-OH group and shows the presence ofpolyacrylic acid grafted on the polystyrene.The grafting degree obtained by XPS is in agreement with that from the gravimetric method.

  11. Organising pneumonia associated with fumaric acid ester treatment for psoriasis.

    LENUS (Irish Health Repository)

    Deegan, Alexander Paul

    2012-02-01

    INTRODUCTION: We present the case of a 49-year old male who presented with dyspnoea, cough, weight loss, night sweats and general malaise. He had been on treatment with oral fumaric acid esters (FAE, Fumaderm(R); Biogen Idec GmbH, Ismaning, Germany) for 6 months. METHODS: Report of a case. RESULTS: His chest X-ray showed patchy infiltrates in the left upper lobe which failed to resolve under empiric antibiotic therapy. A computed tomography of thorax revealed bilateral, mostly peripheral foci of consolidation with air bronchograms. Transbronchial biopsies showed a pattern of organising pneumonia (OP). CONCLUSIONS: Therapy with oral prednisolone (40 mg\\/day) resulted in a rapid clinical and radiological improvement. An association of FAE and OP has not previously been reported. Please cite this paper as: Deegan AP, Kirby B, Rogers S, Crotty TB and McDonnell TJ. Organising pneumonia associated with fumaric acid ester treatment for psoriasis.

  12. Enzymatic synthesis and application of fatty acid ascorbyl esters

    Directory of Open Access Journals (Sweden)

    Stojanović Marija M.

    2013-01-01

    Full Text Available Fatty acid ascorbyl esters are liposoluble substances that possess good antioxidative properties. These compounds could be synthesized by using various acyl donors for acylation of vitamin C in reaction catalyzed by chemical means or lipases. Enzymatic process is preferred since it is regioselective, performed under mild reaction conditions, with the obtained product being environmentally friendly. Polar organic solvents, ionic liquids, and supercritical fluids has been successfully used as a reaction medium, since commonly used solvents with high Log P values are inapplicable due to ascorbic acid high polarity. Acylation of vitamin C using fatty acids, their methyl-, ethyl-, and vinyl esters, as well as triglycerides has been performed, whereas application of the activated acyl donors enabled higher molar conversions. In each case, majority of authors reported that using excessive amount of the acyl donor had positive effect on yield of product. Furthermore, several strategies have been employed for shifting the equilibrium towards the product by water content control. These include adjusting the initial water activity by pre-equilibration of reaction mixture, enzyme preparation with water vapor of saturated salt solutions, and the removal of formed water by the addition of molecular sieves or salt hydrate pairs. The aim of this article is to provide a brief overview of the procedures described so far for the lipase-catalyzed synthesis of fatty acid ascorbyl esters with emphasis on the potential application in food, cosmetics, and pharmaceutics. Furthermore, it has been pointed out that the main obstacles for process commercialization are long reaction times, lack of adequate purification methods, and high costs of lipases. Thus, future challenges in this area are testing new catalysts, developing continuous processes for esters production, finding cheaper acyl donors and reaction mediums, as well as identifying standard procedures for

  13. Evaluation of salicylic acid fatty ester prodrugs for UV protection.

    Science.gov (United States)

    Im, Jong Seob; Balakrishnan, Prabagar; Oh, Dong Hoon; Kim, Jung Sun; Jeon, Eun-Mi; Kim, Dae-Duk; Yong, Chul Soon; Choi, Han-Gon

    2011-07-01

    The purpose of this study was to investigate the physicochemical properties and in vitro evaluation of fatty ester prodrugs of salicylic acid for ultraviolet (UV) protection. The physicochemical properties such as lipophilicity, chemical stability and enzymatic hydrolysis were investigated with the following fatty ester prodrugs of salicylic acid: octanoyl (C8SA), nonanoyl (C9SA), decanoyl (C10SA), lauroyl (C12SA), myristoyl (C14SA) and palmitoyl oxysalicylate (C16SA). Furthermore, their skin permeation and accumulation were evaluated using a combination of common permeation enhancing techniques such as the use of a lipophilic receptor solution, removal of stratum corneum and delipidization of skin. Their k' values were proportional to the degree of carbon-carbon saturation in the side chain. All these fatty esters were highly stable in 2-propanol, acetonitrile and glycerin, but unstable in methanol and ethanol. They were relatively unstable in liver and skin homogenates. In particular, C16SA was mostly hydrolyzed to its parent compound in hairless mouse liver and skin homogenates, suggesting that it might be converted to salicylic acid after its topical administration. In the skin permeation and accumulation study, C16SA showed the poorest permeation in all skins, suggesting that it could not be permeated in the skin. Furthermore, C14SA and C16SA were less accumulated in delipidized skin compared with normal skin or stripped skin, suggesting that these esters had relatively strong affinities for lipids compared with the other prodrugs in the skin. C16SA showed significantly higher dermal accumulation in all skins compared with its parent salicylic acid. Thus, the palmitoyl oxysalicylate (C16SA) might be a potential candidate for UV protection due to its absence of skin permeation, smaller uptake in the lipid phase and relatively lower skin accumulation.

  14. 21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyhydric alcohol esters of long chain monobasic..., PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3780 Polyhydric alcohol esters of long chain monobasic acids. Polyhydric alcohol esters of long chain monobasic acids identified in...

  15. 40 CFR 721.9965 - Fatty acids, C10-13 - branched, vinyl esters.

    Science.gov (United States)

    2010-07-01

    ... esters. 721.9965 Section 721.9965 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.9965 Fatty acids, C10-13 - branched, vinyl esters. (a) Chemical... acids, C10-13 - branched, vinyl esters (PMN P-97-482; CAS No. 184785-38-4) is subject to reporting...

  16. 40 CFR 721.10133 - 2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer.

    Science.gov (United States)

    2010-07-01

    ...-hydroxyethyl ester, homopolymer. 721.10133 Section 721.10133 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10133 2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester... identified as 2-propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer (PMN P-07-401; CAS No....

  17. 40 CFR 721.10165 - Carbonotrithioic acid, bis(phenylmethyl) ester.

    Science.gov (United States)

    2010-07-01

    ...(phenylmethyl) ester. 721.10165 Section 721.10165 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10165 Carbonotrithioic acid, bis(phenylmethyl) ester. (a) Chemical... carbonotrithioic acid, bis(phenylmethyl) ester (PMN P-08-138; CAS No.26504-29-0) is subject to reporting under...

  18. 40 CFR 721.2078 - 1-Piperidinecarboxylic acid, 2-[(dichloro-hydroxy-carbomonocycle)hydrazono]-, methyl ester...

    Science.gov (United States)

    2010-07-01

    ...- -, methyl ester (generic). 721.2078 Section 721.2078 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.2078 1-Piperidinecarboxylic acid, 2- -, methyl ester... generically identified as 1-piperidinecarboxylic acid, 2- -, methyl ester (PMN P-96-756) is subject...

  19. 40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.

    Science.gov (United States)

    2010-07-01

    ... acid ester, substituted amine salt. 721.7770 Section 721.7770 Protection of Environment ENVIRONMENTAL... ester, substituted amine salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as alkyl phenoxypoly(oxyethylene) sulfuric acid ester,...

  20. 40 CFR 721.1577 - 1,4-Benzenedicarboxylic acid, bis [4-(ethenyloxy) butyl] ester.

    Science.gov (United States)

    2010-07-01

    ... ester. 721.1577 Section 721.1577 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.1577 1,4-Benzenedicarboxylic acid, bis ester. (a) Chemical substance and... acid, bis ester (PMN P-98-1163; CAS No. 117397-31-6) is subject to reporting under this section for...

  1. 78 FR 46283 - Modification of Significant New Uses of Ethaneperoxoic Acid, 1,1-Dimethylpropyl Ester

    Science.gov (United States)

    2013-07-31

    ...- Dimethylpropyl Ester AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: Under the Toxic... chemical substance identified as ethaneperoxoic acid, 1,1- dimethylpropyl ester, which was the subject of... substance identified as ethaneperoxoic acid, 1,1-dimethylpropyl ester, (PMN P-85-680). Potentially...

  2. 40 CFR 721.987 - Dialkylaminophenyl imino pyrazole acid ester (generic).

    Science.gov (United States)

    2010-07-01

    ... ester (generic). 721.987 Section 721.987 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.987 Dialkylaminophenyl imino pyrazole acid ester (generic). (a) Chemical... as dialkylaminophenyl imino pyrazole acid ester (PMN P-98-45) is subject to reporting under...

  3. 40 CFR 721.1579 - 1,2,4-Benzenetricarboxylic acid, tris [4-(ethenyloxy) butyl] ester.

    Science.gov (United States)

    2010-07-01

    ... ester. 721.1579 Section 721.1579 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.1579 1,2,4-Benzenetricarboxylic acid, tris ester. (a) Chemical substance...-benzenetricarboxylic acid, tris ester (PMN P-98-1165; CAS No. 196109-17-8) is subject to reporting under this...

  4. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Science.gov (United States)

    2010-07-01

    ... ester with pentaerythritol. 721.3680 Section 721.3680 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.3680 Ethylene oxide adduct of fatty acid ester with... identified generically as ethylene oxide adduct of fatty acid ester with pentaerythritol (PMN P-91-442)...

  5. 40 CFR 721.8160 - Propanoic acid, 2,2-dimethyl-, ethenyl ester.

    Science.gov (United States)

    2010-07-01

    ... ester. 721.8160 Section 721.8160 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.8160 Propanoic acid, 2,2-dimethyl-, ethenyl ester. (a) Chemical... acid, 2,2-dimethyl-, ethenyl ester (PMN P-89-1058) is subject to reporting under this section for...

  6. 40 CFR 721.7290 - Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester.

    Science.gov (United States)

    2010-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to...

  7. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    Science.gov (United States)

    Liu, Hanzhou; Yu, Ming; Ma, Hongjuan; Wang, Ziqiang; Li, Linfan; Li, Jingye

    2014-01-01

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions.

  8. Separation of water and oil by poly (acrylic acid)-coated stainless steel mesh prepared by radiation crosslinking

    Energy Technology Data Exchange (ETDEWEB)

    Nho, Young Chang; Shin, Jung Woong; Park, Jong Seok; Lim, Young Mook; Jeun, Joon Pyo; Kang, Phil Hyun [Research Division for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2015-05-15

    The stainless steel mesh coated with poly(acrylic acid) hydrogel was fabricated and applied for the separation of water and oil. The stainless steel mesh was immersed in aqueous poly (acrylic acid) solution, and then irradiated by radiation to introduce poly(acrylic acid) hydrogel on the surface of mesh by crosslinking. It was possible to separate oil and water from mixtures of oil/water effectively using the hydrogel-coated mesh. The effect of irradiation dose, coating thickness, size of mesh on the separation efficiency was examined.

  9. Fatty acid methyl ester profiles of bat wing surface lipids.

    Science.gov (United States)

    Pannkuk, Evan L; Fuller, Nathan W; Moore, Patrick R; Gilmore, David F; Savary, Brett J; Risch, Thomas S

    2014-11-01

    Sebocytes are specialized epithelial cells that rupture to secrete sebaceous lipids (sebum) across the mammalian integument. Sebum protects the integument from UV radiation, and maintains host microbial communities among other functions. Native glandular sebum is composed primarily of triacylglycerides (TAG) and wax esters (WE). Upon secretion (mature sebum), these lipids combine with minor cellular membrane components comprising total surface lipids. TAG and WE are further cleaved to smaller molecules through oxidation or host enzymatic digestion, resulting in a complex mixture of glycerolipids (e.g., TAG), sterols, unesterified fatty acids (FFA), WE, cholesteryl esters, and squalene comprising surface lipid. We are interested if fatty acid methyl ester (FAME) profiling of bat surface lipid could predict species specificity to the cutaneous fungal disease, white nose syndrome (WNS). We collected sebaceous secretions from 13 bat spp. using Sebutape(®) and converted them to FAME with an acid catalyzed transesterification. We found that Sebutape(®) adhesive patches removed ~6× more total lipid than Sebutape(®) indicator strips. Juvenile eastern red bats (Lasiurus borealis) had significantly higher 18:1 than adults, but 14:0, 16:1, and 20:0 were higher in adults. FAME profiles among several bat species were similar. We concluded that bat surface lipid FAME profiling does not provide a robust model predicting species susceptibility to WNS. However, these results provide baseline data that can be used for lipid roles in future ecological studies, such as life history, diet, or migration.

  10. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-01-15

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  11. Dehydration of lactic acid to acrylic acid over lanthanum phosphate catalysts: the role of Lewis acid sites.

    Science.gov (United States)

    Guo, Zhen; Theng, De Sheng; Tang, Karen Yuanting; Zhang, Lili; Huang, Lin; Borgna, Armando; Wang, Chuan

    2016-09-14

    Lanthanum phosphate (LaP) nano-rods were synthesized using n-butylamine as a shape-directing agent (SDA). The resulting catalysts were applied in the dehydration of lactic acid to acrylic acid. Aiming to understand the nature of the active sites, the chemical and physical properties of LaP materials were studied using a variety of characterization techniques. This study showed that the SDA not only affected the porosity of the LaP materials but also modified the acid-base properties. Clearly, the modification of the acid-base properties played a more critical role in determining the catalytic performance than porosity. An optimized catalytic performance was obtained on the LaP catalyst with a higher concentration of Lewis acid sites. Basic sites showed negative effects on the stability of the catalysts. Good stability was achieved when the catalyst was prepared using the appropriate SDA/La ratio.

  12. 21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl and ethyl esters of fatty acids produced... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters... following prescribed conditions: (a) The additive consists of a mixture of either methyl or ethyl esters...

  13. Photo-Reversible Supramolecular Hydrogels Assembled by α-Cyclodextrin and Azobenzene Substituted Poly(acrylic acid)s

    NARCIS (Netherlands)

    Wang, Mingwei; Zhang, Xiaojun; Li, Li; Wang, Junyou; Wang, Jie; Ma, Jun; Yuan, Zhenyu; Lincoln, Stephen F.; Guo, Xuhong

    2016-01-01

    Photo-reversible supramolecular hydrogels based on the mixture of α-cyclodextrin (α-CD) and azobenzene (Azo) substituted poly(acrylic acid) s were prepared. Effects of substitution degree of Azo, polymer concentration and tethered chain length on the reversible sol-gel transition of these mixture

  14. Superabsorbent biphasic system based on poly(lactic acid) and poly(acrylic acid)

    Science.gov (United States)

    Sartore, Luciana; Pandini, Stefano; Baldi, Francesco; Bignotti, Fabio

    2016-05-01

    In this research work, biocomposites based on crosslinked particles of poly(acrylic acid), commonly used as superabsorbent polymer (SAP), and poly-L-lactic acid (PLLA) were developed to elucidate the role of the filler (i.e., polymeric crosslinked particles) on the overall physico-mechanical behavior and to obtain superabsorbent thermoplastic products. Samples prepared by melt-blending of components in different ratios showed a biphasic system with a regular distribution of particles, with diameter ranging from 5 to 10 μm, within the PLLA polymeric matrix. The polymeric biphasic system, coded PLASA i.e. superabsorbent poly(lactic acid), showed excellent swelling properties, demonstrating that cross-linked particles retain their superabsorbent ability, as in their free counterparts, even if distributed in a thermoplastic polymeric matrix. The thermal characteristics of the biocomposites evidence enhanced thermal stability in comparison with neat PLLA and also mechanical properties are markedly modified by addition of crosslinked particles which induce regular stiffening effect. Furthermore, in aqueous environments the particles swell and are leached from PLLA matrix generating very high porosity. These new open-pore PLLA foams, produced in absence of organic solvents and chemical foaming agents, with good physico-mechanical properties appear very promising for several applications, for instance in tissue engineering for scaffold production.

  15. Cu(I)-catalyzed (11)C carboxylation of boronic acid esters: a rapid and convenient entry to (11)C-labeled carboxylic acids, esters, and amides.

    Science.gov (United States)

    Riss, Patrick J; Lu, Shuiyu; Telu, Sanjay; Aigbirhio, Franklin I; Pike, Victor W

    2012-03-12

    Rapid and direct: the carboxylation of boronic acid esters with (11)CO(2) provides [(11)C]carboxylic acids as a convenient entry into [(11)C]esters and [(11)C]amides. This conversion of boronates is tolerant to diverse functional groups (e.g., halo, nitro, or carbonyl).

  16. Exploring unsaturated fatty acid cholesteryl esters as transdermal permeation enhancers.

    Science.gov (United States)

    Rambharose, Sanjeev; Kalhapure, Rahul S; Jadhav, Mahantesh; Govender, Thirumala

    2017-04-01

    The intrinsic protective barrier property of skin, one of the major challenges in the design of transdermal drug delivery systems, can be overcome through the use of chemical permeation enhancers (CPEs). Herein, we explore the potential of unsaturated fatty acid (UFA) esters of cholesterol (Chol) viz., oleate, linoleate and linolenate, as transdermal CPEs using tenofovir (TNF) as a model drug. All Chol UFA esters at 1% w/w were found to be more effective enhancers when compared to their respective parent fatty acids (FAs) and saturated FA counterparts. Cholesteryl linolenate (Chol-LLA) showed the most superior performance (enhancement ratio (ER) = 3.71). The greatest ER for Chol-LLA (5.93) was achieved at a concentration of 2% w/w. The histomorphological and transepithelial electrical resistance (TEER) evaluations supported the results of the permeability studies. These findings showed no significant loss in the integrity of the epidermis, with drug and enhancer treatment having temporary effects on the barrier property of the epidermis. Chol UFA esters can therefore be considered as new CPEs for exploitation in topical formulations for various classes of drugs.

  17. Metabolism of hydroxycinnamic acids and their tartaric acid esters by Brettanomyces and Pediococcus in red wines.

    Science.gov (United States)

    Caffeic, p-coumaric, and ferulic acids and their corresponding tartaric acid esters (caftaric, coutaric, and fertaric, respectively) are found in wines in varying concentrations. While Brettanomyces and Pediococcus can utilize the free acids, it is not known whether they can metabolize the correspon...

  18. Nanoparticles of Block Ionomer Complexes from Double Hydrophilic Poly(acrylic acid-b-poly(ethylene oxide-b-poly(acrylic acid Triblock Copolymer and Oppositely Charged Surfactant

    Directory of Open Access Journals (Sweden)

    Sun Yuelong

    2009-01-01

    Full Text Available Abstract The novel water-dispersible nanoparticles from the double hydrophilic poly(acrylic acid-b-poly(ethylene oxide-b-poly(acrylic acid (PAA-b-PEO-b-PAA triblock copolymer and oppositely charged surfactant dodecyltrimethyl ammonium bromide (DTAB were prepared by mixing the individual aqueous solutions. The structure of the nanoparticles was investigated as a function of the degree of neutralization (DN by turbidimetry, dynamic light scattering (DSL,ζ-potential measurement, and atomic force microscope (AFM. The neutralization of the anionic PAA blocks with cationic DTAB accompanied with the hydrophobic interaction of alkyl tails of DTAB led to formation of core–shell nanoparticles with the core of the DTAB neutralized PAA blocks and the shell of the looped PEO blocks. The water-dispersible nanoparticles with negative ζ-potential were obtained over the DN range from 0.4 to 2.0 and their sizes depended on the DN. The looped PEO blocks hindered the further neutralization of the PAA blocks with cationic DTAB, resulting in existence of some negative charged PAA-b-PEO-b-PAA backbones even when DN > 1.0. The spherical and ellipsoidal nature of these nanoparticles was observed with AFM.

  19. Synthesis and characterization of amphiphilc block copolymer poly(methyl acrylic acid)-block-polytetrahydrofuran

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Under the specially designated condition the polymerization of both tetrahydrofuran (THF) and tert-butyl methacrylate (tBMA) is a living one. The diblock copolymer, poly(tert-butyl methacrylate)-block-polytetrahydrofuran (PtBMA-b-PTHF), was successfully synthesized by means of the coupling reaction of living cationic PTHF+, SbF6- with living anionic PtBMA-, Li+. LiCl, which has a beneficial effect on the molecular weight distribution (MWD) in the anionic polymerization of (meth)acrylates, hinders the coupling reaction of living chains and cannot be used in the preparation of tBMA precursor. The hydrolysis of the aforementioned diblock copolymer under acid condition results in the amphiphilic diblock copolymer, i.e. poly(methyl acrylic acid)-block-polytetra- hydrofuran (PMAA-b-PTHF). The diblock copolymers were characterized with GPC and IR.

  20. Spectroscopy of a Gamma Irradiated Poly(Acrylic Acid)-Clotrimazole System

    Institute of Scientific and Technical Information of China (English)

    M.Todica; C.V.Pop; Luciana Udrescu; Traian Stefan

    2011-01-01

    A poly(acrylic acid)-clotrimazole system,gamma irradiated at different doses,is investigated by Raman spectroscopy.Modifications of the spectrum of the polymeric matrix appear for doses of radiation greater than 333 Gy,whereas the spectrum of clotrimazole remains unaffected at these doses of radiation.These changes correlate with modification of the vibration modes of COOH and CH2 groups of a polymeric matrix after irradiation.%A poly(acrylic acid)-clotrimazole system, gamma irradiated at different doses, is investigated by Raman spec-troscopy. Modifications of the spectrum of the polymeric matrix appear for doses of radiation greater than 333 Gy, whereas the spectrum of clotrimazole remains unaffected at these doses of radiation. These changes correlate with modification of the vibration modes of COOH and CH2 groups of a polymeric matrix after irradiation.

  1. Dispersion and film-forming properties of poly(acrylic acid)-stabilized carbon nanotubes.

    Science.gov (United States)

    Saint-Aubin, Karell; Poulin, Philippe; Saadaoui, Hassan; Maugey, Maryse; Zakri, Cécile

    2009-11-17

    We present a detailed study of the influence of pH on the dispersion and film-forming properties of poly(acrylic acid)-stabilized carbon nanotubes. Poly(acrylic acid) (PAA) is a weak polyelectrolyte, with a pH-responsive behavior in aqueous solution. We obtain quantitative UV-visible measurements to show that the amount of polyelectrolyte in optimal pH conditions is weak, showing a good efficiency of the polymer as a carbon nanotube dispersing agent. The best dispersion conditions are achieved at pH 5, a value close to the pK(a) of PAA. Apart from this tenuous pH value, the PAA is not efficient at stabilizing nanotubes and atomic force microscopy allows us to explain the delicate balance between the PAA adsorption and the suspension stability. This study finally permits optimal conditions for making homogeneous and conductive composite films to be determined.

  2. One-step routes from di- and triblock copolymer precursors to hydrophilic nanoporous poly(acrylic acid)-b-polystyrene

    DEFF Research Database (Denmark)

    Guo, Fengxiao; Jankova Atanasova, Katja; Schulte, Lars;

    2008-01-01

    Nanoporous polystyrene with hydrophilic pores was prepared from di- and triblock copolymer precursors. The precursor material was either a poly(tert-butyl acryl ate)-b-polystyrene (PtBA-b-PS) diblock copolymer synthesized by atom transfer radical polymerization (ATRP) or a polydimethylsiloxane......-b-poly(tertbutyl acrylate)-b-polystyrene (PDMS-b-PtBA-b-PS) triblock copolymer synthesized by a combination of living anionic polymerization and ATRP. In the latter copolymer, PS was the matrix and mechanically stable component, PtBA was converted by acidic deprotection to hydrophilic poly(acrylic acid) (PAA) providing...

  3. Modification of hydrophobic polypeptide-based film by blending with hydrophilic poly(acrylic acid)

    OpenAIRE

    Guoquan Zhu; Fagang Wang; Qiaochun Gao; Yuying Liu

    2013-01-01

    In this study, a series of poly(γ-benzyl L-glutamate)/poly(acrylic acid) (PBLG/PAA) polymer blend films were prepared by casting the polymer blend solution in dimethylsulfoxide (DMSO). The structure and morphology of the polymer blend film were investigated by Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Thermal, mechanical, and chemical properties of PBLG/PAA polymer blend films were studied by Differential Scanning Calorimetry (DSC), Thermogra...

  4. Thermal preparation of chitosan-acrylic acid superabsorbent: optimization, characteristic and water absorbency.

    Science.gov (United States)

    Ge, Huacai; Wang, Senkang

    2014-11-26

    Chitosan-acrylic acid superabsorbent polymer was successfully prepared by the thermal reaction without using initiator and crosslinker in air. The effects of some reaction variables on the water absorbency of this polymer were investigated by orthogonal tests, and the optimal conditions were described. The influences of temperature, time, ratio of the reactants and neutralization degree of acrylic acid on the reaction were further studied. These polymers were also prepared in nitrogen atmosphere and by using a radical initiator and compared against thermal reaction obtained polymers. The structures of the polymers were characterized by FT-IR, TGA, XRD, (13)C NMR and elemental analyses. The results showed that the thermal reaction product of acrylic acid with chitosan might form N-carboxyethyl grafted and amide-linked polymer and this product could absorb water 644 times its own dry weight. The possible mechanism for the thermal reaction was further suggested. The purpose of this research was to explore the friendly synthesized method of the superabsorbent.

  5. Acrylic acid polymerization and its graft copolymerization to poly(ethylene oxide) by gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Hochberg, A.

    1984-01-01

    Free radical initiated polymerization of acrylic acid was investigated in methanol-water solutions with and without poly(ethylene oxide) (PEO). The formation of poly(acrylic acid) (PAA) initiated both by gamma irradiation and water soluble azo initiators was found to follow classical free radical kinetics. A significant increase in the rate of the propagation step (together with the degree of polymerization) was observed as the water fraction of the medium increased. During homogeneous polymerization of acrylic acid in methanol-water solutions containing poly(ethylene oxide), PAA grafting efficiency was found to be 67% and independent of initiation rate and yield. A mechanism of grafting to poly(ethylene oxide) was proposed. Chain transfer to PEO (K/sub tr/ = 6.5 x 10/sup -5/) was found to be the dominant mechanism for graft formation. Drag reduction characteristics of these PEO-PAA graft copolymers were measured in dilute aqueous solutions as a function of Reynolds number and solution pH. PEO graft copolymers containing 45% by mole PAA graft had, in neutral and basic solutions, drag reduction characteristics equivalent on a mass basis to the initial PEO. However at low pH, drag reduction characteristics disappeared as the PEO-PAA coacervate formed.

  6. Optimization of acrylic acid grafting onto polypropylene using response surface methodology and its biodegradability

    Science.gov (United States)

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Kushwaha, Jai P.; Chaudhari, Chandrasekhar V.; Dubey, Kumar A.; Varshney, Lalit

    2017-03-01

    Simultaneous radiation grafting was optimized to graft acrylic acid monomer on the polypropylene (PP) films to make them hydrophilic and enhance their biodegradability. Experiments were designed based on full factorial central composite design (response surface methodology) and influence of monomer concentration, radiation dose, inhibitor concentration, solvent concentration on degree of grafting was investigated. The extent of grafting was found to increase with increasing monomer concentration, inhibitor concentration and radiation dose. The targeted 35% grafting could be achieved at optimum condition viz. monomer concentration 12.09 wt%, radiation dose 12.40 kGy, inhibitor concentration 0.07 M and solvent concentration 0.12 M. The grafted PP films at different degrees of grafting were tested for tensile properties and characterized by swelling studies, fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Successful grafting of acrylic acid onto polypropylene films was indicated by FTIR and confirmed quantitatively by determination of carboxylic groups on the film surface. Tensile strength of grafted PP films decreased with increase in degree of grafting. The crystallinity of the grafted PP films was lower than that of PP film as indicated by DSC studies. Grafting of acrylic acid increased the roughness on the surface of PP films indicated by SEM studies. The maximum biodegradability of the 34.55% grafted film was 5.5%.

  7. Preparation and characterization of poly(acrylic acid)-hydroxyethyl cellulose graft copolymer.

    Science.gov (United States)

    Abdel-Halim, E S

    2012-10-01

    Poly(acrylic acid) hydroxyethyl cellulose [poly(AA)-HEC] graft copolymer was prepared by polymerizing acrylic acid (AA) with hydroxyethyl cellulose (HEC) using potassium bromate/thiourea dioxide (KBrO(3)/TUD) as redox initiation system. The polymerization reaction was carried out under a variety of conditions including concentrations of AA, KBrO(3) and TUD, material to liquor ratio and polymerization temperature. The polymerization reaction was monitored by withdrawing samples from the reaction medium and measuring the total conversion. The rheological properties of the poly(AA)-HEC graft copolymer were investigated. The total conversion and rheological properties of the graft copolymer depended on the ratio of KBrO(3) to TUD and on acrylic acid concentration as well as temperature and material to liquor ratio. Optimum conditions of the graft copolymer preparation were 30 mmol KBrO(3) and 30 mmol TUD/100g HEC, 100% AA (based on weight of HEC), duration 2h at temperature 50 °C using a material to liquor ratio of 1:10.

  8. Investigation on the Inverse Emulsion Polymerization of Acrylic Acid

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Polyacrylic acid particles in nano-scale were synthesized using an inverse (W/O) emulsion polymerization method. The particle size and size change of inverse micelles which solubilize a part of monomer solution was monitored by PCS (photon correlation spectroscopy) and the particles of polyacrylic acid were viewed in scanning electron microscope for the first time. It was concluded that the inverse micelles were primarily the polymerization reaction sites.

  9. Influence of ozone and paracetic acid disinfection on adhesion of resilient liners to acrylic resin

    Science.gov (United States)

    2016-01-01

    PURPOSE The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials. PMID:27555898

  10. Antifungal activity of 4-substituted crotonic acid esters.

    Science.gov (United States)

    Gershon, H; Shanks, L; Gawiak, D E

    1976-08-01

    Twenty-three 4-substituted crotonic acid esters were tested for antifungal activity against Candida albicans, Aspergillus niger, Mucor mucedo, and Trichophyton mentagrophytes. For the analogues of the methyl ester containing substituents in the 4 position, the following order of fungitoxicity was observed: I greater than Br greater than Cl greater than CH3S greater than CH3O greater than F=H. Of the homologues of the esters of the 4-iodo and 4-bromo compounds which included methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl, ethyl 4-iodocrotonate was most toxic to the four fungi at pH 7.0 in the presence of 10% beef serum (C. albicans, 18mug/ml, A. niger, 40 mug/ml, M. mucedo, 5 mug/ml, T. mentagrophytes, 4 mug/ml). It is believed that the mechanism of fungitoxicity is due, in part, to a nucleophilic reaction involving SH-containing compounds. This is based on the correlation of fungitoxicity with the order of leaving groups in the nucleophilic reaction and the protection against the toxicity of the test compounds to the fungi by cysteine and glutathione.

  11. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Science.gov (United States)

    2010-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  12. 40 CFR 721.10142 - Oxabicycloalkane carboxylic acid alkanediyl ester (generic).

    Science.gov (United States)

    2010-07-01

    ... alkanediyl ester (generic). 721.10142 Section 721.10142 Protection of Environment ENVIRONMENTAL PROTECTION... ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as oxabicycloalkane carboxylic acid alkanediyl ester (PMN P-06-199)...

  13. 40 CFR 721.6075 - Phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester.

    Science.gov (United States)

    2010-07-01

    ...-tetrakis(1-methylethyl) ester. 721.6075 Section 721.6075 Protection of Environment ENVIRONMENTAL PROTECTION...-methylethyl) ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester (PMN P-95-168)...

  14. 40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.

    Science.gov (United States)

    2010-07-01

    ...)amino-, methyl ester. 721.1728 Section 721.1728 Protection of Environment ENVIRONMENTAL PROTECTION...-, methyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester (PMN P-85-1211) is...

  15. ESTIMATION OF HYDROLYSIS RATE CONSTANTS OF CARBOXYLIC ACID ESTER AND PHOSPHATE ESTER COMPOUNDS IN AQUEOUS SYSTEMS FROM MOLECULAR STRUCTURE BY SPARC

    Science.gov (United States)

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate hydrolysis rate constants for carboxylic acid ester and phosphate ester compounds in aqueous non- aqueous and systems strictly from molecular structure. The energy diffe...

  16. Cyclodextrin-crosslinked poly(acrylic acid): Synthesis, physicochemical characterization and controlled release of diflunisal and fluconazole from hydrogels.

    Science.gov (United States)

    Kutyła, Marguerite J; Lambert, Lynette K; Davies, Nigel M; McGeary, Ross P; Shaw, P Nicholas; Ross, Benjamin P

    2013-02-28

    The aim of this work was to develop mucoadhesive hydrogels with variable drug delivery properties by crosslinking poly(acrylic acid) (PAA) with cyclodextrins (CDs). CD-PAA polymers with high CD content and good inter-batch reproducibility were synthesized by activating PAA with SOCl2, then reacting PAA chloride with CD in the presence of 4-dimethylaminopyridine at 50°C. Manipulation of the synthesis conditions affected the physicochemical character of the CD-PAA polymers and hydrogels in terms of CD content, the average number of ester bonds to an individual CD, viscosity, and the association and release of model drugs. Inclusion complexation of diflunisal (DIF) and fluconazole (FLZ) with CD-PAA hydrogels was assessed by (19)F NMR spectroscopy and association constants (Kas) for DIF were in the range 220-486M(-1) with βCD-PAA and 1327-6055M(-1) with hydroxypropyl-βCD-PAA. For FLZ the Ka range was 34-171M(-1) with hydroxypropyl-βCD-PAA. The hydrogels were found to release both drugs by means of Fickian diffusion as the predominant mechanism. A slight trend toward negative correlation was found between the Ka and Higuchi kH values for DIF. These results highlight the potential of CD-PAA hydrogels to control the release of model drugs through inclusion complexation.

  17. Synthesis of N-(methoxycarbonyl or isopropylcarbamoyl- methoxyphosphonyl)-α-amino acid ester and their stereomers

    Institute of Scientific and Technical Information of China (English)

    陈茹玉; 李慧英

    1996-01-01

    N-(methoxycarbonyl-methoxyphosphonyl)-α-amino add esters (I) were synthesized via the reaction of the corresponding phosphonyl chloride with amino acid ester hydrochlorides in the presence of a base. Compound I was aminated to yield N-(isopropylcarbainoyl-methoxyphosphonyl)-α-amino acid esters (II). With l-amino acids as starting materials, the isomers of products I and II were separated and their configurations were confirmed by the single crystal X-ray diffraction of II.

  18. A Convenient, General Synthesis of 1,1-Dimethylallyl Esters as Protecting Groups for Carboxylic Acids

    Science.gov (United States)

    Sedighi, Minoo; Lipton, Mark A.

    2006-01-01

    Carboxylic acids were converted in high yield to their 1,1-dimethylallyl (DMA) esters in two steps. Palladium-catalyzed deprotection of DMA esters was shown to be compatible with tert-butyl, benzyl and Fmoc protecting groups, and Fmoc deprotection could be carried out selectively in the presence of DMA esters. DMA esters were also shown to be resistant to nucleophilic attack, suggesting that they will serve as alternatives to tert-butyl esters when acidic deprotection conditions need to be avoided. PMID:15816730

  19. A convenient, general synthesis of 1,1-dimethylallyl esters as protecting groups for carboxylic acids.

    Science.gov (United States)

    Sedighi, Minoo; Lipton, Mark A

    2005-04-14

    [reaction: see text] Carboxylic acids were converted in high yield to their 1,1-dimethylallyl (DMA) esters in two steps. Palladium-catalyzed deprotection of DMA esters was shown to be compatible with tert-butyl, benzyl, and Fmoc protecting groups, and Fmoc deprotection could be carried out selectively in the presence of DMA esters. DMA esters were also shown to be resistant to nucleophilic attack, suggesting that they will serve as alternatives to tert-butyl esters when acidic deprotection conditions need to be avoided.

  20. Superiorly Plasticized PVC/PBSA Blends through Crotonic and Acrylic Acid Functionalization of PVC

    Directory of Open Access Journals (Sweden)

    Arturo Salazar Avalos

    2017-03-01

    Full Text Available Superior plasticization efficiency was achieved by a grafting from functionalization of the PVC backbone. This was deduced to a synergistic effect of internal plasticization and improved intermolecular interactions between PVC and an oligomeric poly(butylene succinate-co-adipate (PBSA plasticizer. A mild grafting process for functionalization of the PVC chain by crotonic acid (CA or acrylic acid (AA was used. The formation of PVC-g-CA and PVC-g-AA was confirmed by FTIR and 1H NMR. Grafting with the seemingly similar monomers, CA and AA, resulted in different macromolecular structures. AA is easily homopolymerized and long hydrophilic poly(acrylic acid grafts are formed resulting in branched materials. Crotonic acid does not easily homopolymerize; instead, single crotonic acid units are located along the PVC chain, leading to basically linear PVC chains with pendant crotonic acid groups. The elongation of PVC-g-CA and PVC-g-AA in comparison to pure PVC were greatly increased from 6% to 128% and 167%, respectively, by the grafting reactions. Blending 20% (w/w PBSA with PVC, PVC-AA or PVC-CA further increased the elongation at break to 150%, 240% and 320%, respectively, clearly showing a significant synergistic effect in the blends with functionalized PVC. This is a clearly promising milestone towards environmentally friendly flexible PVC materials.

  1. Radiation-induced graft polymerization of acrylamide and acrylic acid onto polyethylene

    Science.gov (United States)

    Grushevskaya, L. N.; Aliev, R. E.; Kabanov, V. Ya.

    The radiation-induced grafting of acrylamide onto low-density polyethylene by the different methods and under different conditions was investigated: by the direct liquid phase method from this monomer solution in water (in neutral and acid media) and acetone, and by the pre-irradiation method from aqueous solutions as well as from its sublimated vapour. The molecular masses of polyacrylamide homopolymers were determined. The discussion and comparison of different methods of acrylamide grafting are performed. The relationship between rates of graft polymerization onto polyethylene and homopolymerization of acrylic acid in the presence of metal ions is considered.

  2. Chemometric analysis of mass spectra of cis and trans fatty acid picolinyl esters

    DEFF Research Database (Denmark)

    Leth, Torben

    1997-01-01

    Capillary GC of fatty acid methyl esters with MS detection only yields information about the molecular weight of the compound. However, if picolinyl esters of fatty acids are analysed in this way it is possible to obtain more information about their structure, perhaps even the cis or trans...... configuration. Picolinyl esters of fatty acids are prepared by adding carbonyl-diimidazole, 3-hydroxy-methylpyridine and 4-pyrrolidin-o-pyridine to a solution of free fatty acids in dichloromethane. The picolinyl esters dissolved in heptane are then separated by capillary GC on a CP Sil 88 column equipped...

  3. Neutral lipid biosynthesis in engineered Escherichia coli: jojoba oil-like wax esters and fatty acid butyl esters.

    Science.gov (United States)

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-02-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms.

  4. A novel alkenoic acid ester and a new benzophenone from Ranunculus ternatus

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel alkenoic acid ester, (E)-4-hydroxy-dodec-2-enedioic acid-12-O-methyl ester and a new benzophenone, ethyl (S)-3-[2-(3,4-dihydroxybenzoyl)-4,5-dihydroxyphenyl]-2-hydroxypropanoate, together with a known compound, (E)-4-hydroxy-dodec-2-enedioic acids were isolated from the roots of Ranunculus ternatus. Their structures were elucidated by spectroscopic methods.

  5. Effect of Grafted Hydroquinone on the Acid-Base Properties of Poly(acrylic acid in the Presence of Copper (II

    Directory of Open Access Journals (Sweden)

    Nabila Bensacia

    2015-01-01

    Full Text Available Potentiometric titration of poly(acrylic acid and hydroquinone-functionalized poly(acrylic acid was conducted in the presence of copper (II. The effects of hydroquinone functionalizing and copper (II complexing on the potentiometric titration of poly(acrylic acid were studied in an ionic environment and in its absence. Henderson-Hasselbalch equation was applied to assess its validity for this titration. Coordination number and the stability constants of the copper- (II-complexed polymers were determined, and results showed the formation of mostly monodentate and bidentate copper- (II-polymer complexes.

  6. Zeolite-catalysed preparation of alpha-hydroxy carboxylic acids and esters thereof

    DEFF Research Database (Denmark)

    2010-01-01

    A process for the production of lactic acid and 2-hydroxy-3-butenoic acid or esters thereof by conversion of glucose, fructose, sucrose, xylose and glycolaldehyde dissolved in a solvent in presence of a solid Lewis acidic catalyst.......A process for the production of lactic acid and 2-hydroxy-3-butenoic acid or esters thereof by conversion of glucose, fructose, sucrose, xylose and glycolaldehyde dissolved in a solvent in presence of a solid Lewis acidic catalyst....

  7. Salicylic acid-releasing polyurethane acrylate polymers as anti-biofilm urological catheter coatings.

    Science.gov (United States)

    Nowatzki, Paul J; Koepsel, Richard R; Stoodley, Paul; Min, Ke; Harper, Alan; Murata, Hironobu; Donfack, Joseph; Hortelano, Edwin R; Ehrlich, Garth D; Russell, Alan J

    2012-05-01

    Biofilm-associated infections are a major complication of implanted and indwelling medical devices like urological and venous catheters. They commonly persist even in the presence of an oral or intravenous antibiotic regimen, often resulting in chronic illness. We have developed a new approach to inhibiting biofilm growth on synthetic materials through controlled release of salicylic acid from a polymeric coating. Herein we report the synthesis and testing of a ultraviolet-cured polyurethane acrylate polymer composed, in part, of salicyl acrylate, which hydrolyzes upon exposure to aqueous conditions, releasing salicylic acid while leaving the polymer backbone intact. The salicylic acid release rate was tuned by adjusting the polymer composition. Anti-biofilm performance of the coatings was assessed under several biofilm forming conditions using a novel combination of the MBEC Assay™ biofilm multi-peg growth system and bioluminescence monitoring for live cell quantification. Films of the salicylic acid-releasing polymers were found to inhibit biofilm formation, as shown by bioluminescent and GFP reporter strains of Pseudomonas aeruginosa and Escherichia coli. Urinary catheters coated on their inner lumens with the salicylic acid-releasing polymer significantly reduced biofilm formation by E. coli for up to 5 days under conditions that simulated physiological urine flow.

  8. Impact of Association Colloids on Lipid Oxidation in Triacylglycerols and Fatty Acid Ethyl Esters.

    Science.gov (United States)

    Homma, Rika; Suzuki, Karin; Cui, Leqi; McClements, David Julian; Decker, Eric A

    2015-11-25

    The impact of association colloids on lipid oxidation in triacylglycerols and fatty acid ethyl esters was investigated. Association colloids did not affect lipid oxidation of high oleic safflower and high linoleic safflower triacylglycerols, but were prooxidative in fish triacylglycerols. Association colloids retarded aldehyde formation in stripped ethyl oleate, linoleate, and fish oil ethyl esters. Interfacial tension revealed that lipid hydroperoxides were surface active in the presence of the surfactants found in association colloids. The lipid hydroperoxides from ethyl esters were less surface active than triacylglycerol hydroperoxides. Stripping decreased iron and copper concentrations in all oils, but more so in fatty acid ethyl esters. The combination of lower hydroperoxide surface activity and low metal concentrations could explain why association colloids inhibited lipid oxidation in fatty acid ethyl esters. This research suggests that association colloids could be used as an antioxidant technology in fatty acid ethyl esters.

  9. Chromatographic, Spectrometric and NMR Characterization of a New Set of Glucuronic Acid Esters Synthesized by Lipase

    Directory of Open Access Journals (Sweden)

    Michel Marlier

    2007-01-01

    Full Text Available An enzymatic synthesis was developed on a new set of D-glucuronic acid esters and particularly the tetradecyl-D-glucopyranosiduronate also named tetradecyl D-glucuronate. Chromatographic analyses revealed the presence of the ester as a mixture of anomeric forms for carbon chain lengths superior to 12. TOF/MS and MS/MS studies confirmed the synthesis of glucuronic acid ester. The NMR study also confirmed the structure of glucuronic acid esters and clearly revealed an anomeric (α/β ratio equivalent to 3/2

  10. Intramolecular interactions in ortho-methoxyalkylphenylboronic acids and their catechol esters

    Science.gov (United States)

    Adamczyk-Woźniak, Agnieszka; Borys, Krzysztof M.; Czerwińska, Karolina; Gierczyk, Błażej; Jakubczyk, Michał; Madura, Izabela D.; Sporzyński, Andrzej; Tomecka, Ewelina

    2013-12-01

    Catechol esters of ortho-methoxyalkylphenylboronic acids have been synthesized and characterized by 17O NMR spectroscopy. The results were compared with the data for the parent acids. The influence of intramolecular and intermolecular hydrogen bonds on the properties of the boronic acids has been discussed. The 17O NMR data for the boronic esters proved that there are no O → B interactions in the investigated compounds. This fact is connected with weak Lewis acidity of the parent acids and their low sugars' receptors activity. Crystal structure of ortho-methoxyphenylboronic acid catechol ester was determined.

  11. [Anaerobic biodegradation of phthalic acid esters (Paes) in municipal sludge].

    Science.gov (United States)

    Liang, Zhi-Feng; Zhou, Wen; Lin, Qing-Qi; Yang, Xiu-Hong; Wang, Shi-Zhong; Cai, Xin-De; Qiu, Rong-Liang

    2014-04-01

    Phthalic acid esters (PAEs), a class of organic pollutants with potent endocrine-disrupting properties, are widely present in municipal sludge. Study of PAEs biodegradation under different anaerobic biological treatment processes of sludge is, therefore, essential for a safe use of sludge in agricultural practice. In this study, we selected two major sludge PAEs, i.e. di-n-butyl phthalate (DBP) and di-(2-enthylhexyl) phthalate (DEHP), to investigate their biodegradation behaviors in an anaerobic sludge digestion system and a fermentative hydrogen production system. The possible factors influencing PAEs biodegradation in relation to changes of sludge properties were also discussed. The results showed that the biodegradation of DBP reached 99.6% within 6 days, while that of DEHP was 46.1% during a 14-day incubation period in the anaerobic digestion system. By comparison, only 19.5% of DBP was degraded within 14 days in the fermentative hydrogen production system, while no degradation was detected for DEHP. The strong inhibition of the degradation of both PAEs in the fermentative hydrogen production system was ascribed to the decreases in microbial biomass and ratios of gram-positive bacteria/gram-negative bacteria and fungi/ bacteria, and the increase of concentrations of volatile fatty acids (e. g. acetic acid, propionic acid and butyric acid) during the fermentative hydrogen-producing process.

  12. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid

    Directory of Open Access Journals (Sweden)

    Hongzhu Liu

    2017-01-01

    Full Text Available Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE, vinyl acetate (VAc, n-butyl acrylate (BA, Veova 10, and acrylic acid (AA. The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  13. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid.

    Science.gov (United States)

    Liu, Hongzhu; Bian, Jiming; Wang, Zhonggang; Hou, Chuan-Jin

    2017-01-22

    Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE), vinyl acetate (VAc), n-butyl acrylate (BA), Veova 10, and acrylic acid (AA). The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV) accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  14. Depigmenting Effect of Kojic Acid Esters in Hyperpigmented B16F1 Melanoma Cells

    Directory of Open Access Journals (Sweden)

    Ahmad Firdaus B. Lajis

    2012-01-01

    Full Text Available The depigmenting effect of kojic acid esters synthesized by the esterification of kojic acid using Rhizomucor miehei immobilized lipase was investigated in B16F1 melanoma cells. The depigmenting effect of kojic acid and kojic acid esters was evaluated by the inhibitory effect of melanin formation and tyrosinase activity on alpha-stimulating hormone- (α-MSH- induced melanin synthesis in B16F1 melanoma cells. The cellular tyrosinase inhibitory effect of kojic acid monooleate, kojic acid monolaurate, and kojic acid monopalmitate was found similar to kojic acid at nontoxic doses ranging from 1.95 to 62.5 μg/mL. However, kojic acid monopalmitate gave slightly higher inhibition to melanin formation compared to other inhibitors at doses ranging from 15.63 to 62.5 μg/mL. Kojic acid and kojic acid esters also show antioxidant activity that will enhance the depigmenting effect. The cytotoxicity of kojic acid esters in B16F1 melanoma cells was significantly lower than kojic acid at high doses, ranging from 125 and 500 μg/mL. Since kojic acid esters have lower cytotoxic effect than kojic acid, it is suggested that kojic acid esters can be used as alternatives for a safe skin whitening agent and potential depigmenting agents to treat hyperpigmentation.

  15. Bioequivalence Demonstration for Ω-3 Acid Ethyl Ester Formulations: Rationale for Modification of Current Guidance.

    Science.gov (United States)

    Maki, Kevin C; Johns, Colleen; Harris, William S; Puder, Mark; Freedman, Steven D; Thorsteinsson, Thorsteinn; Daak, Ahmed; Rabinowicz, Adrian L; Sancilio, Frederick D

    2017-02-08

    The US Food and Drug Administration (FDA) draft guidance for establishing bioequivalence (BE) of ω-3 acid ethyl esters (containing both eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA] as ethyl esters), used to treat severe hypertriglyceridemia, recommends the conduct of 2 studies: one with participants in the fasting state and one with participants in the fed state. For the fasting study, the primary measures of BE are baseline-adjusted EPA and DHA levels in total plasma lipids. For the fed study, the primary measures of BE are EPA and DHA ethyl esters in plasma. This guidance differs from that established for icosapent ethyl (EPA ethyl esters) in which the primary measure of BE is baseline-adjusted total EPA in plasma lipids for both the fasting and fed states. The FDA guidance for ω-3 acid ethyl esters is not supported by their physiologic characteristics and triglyceride-lowering mechanisms because EPA and DHA ethyl esters are best characterized as pro-drugs. This article presents an argument for amending the FDA draft guidance for ω-3 acid ethyl esters to use baseline-adjusted EPA and DHA in total plasma lipids as the primary measures of BE for both fasting and fed conditions. This change would harmonize the approaches for demonstration of BE for ω-3 acid ethyl esters and icosapent ethyl (EPA ethyl esters) products for future development programs and is the most physiologically rational approach to BE testing.

  16. Proteinuria with fumaric acid ester treatment for psoriasis.

    Science.gov (United States)

    Ogilvie, S; Lewis Jones, S; Dawe, R; Foerster, J

    2011-08-01

    Fumaric acid esters (FAE) have been used in the treatment of psoriasis for many years. In general, they are regarded as relatively safe compared with other antipsoriatic systemic treatments, with the most notable adverse effects being gastrointestinal upset, lymphopenia and transient flushing. Renal toxicity has only rarely been reported, and was not found in two independent prospective trials nor in a large retrospective evaluation of almost 1000 patients treated for a median of 44 months. We report three patients developing reversible proteinuria during FAE treatment. One of these displayed the same pattern upon repeated drug administration, thereby clearly indicating FAE treatment to be the causal trigger. The presented cases highlight proteinuria as a clinical concern in FAE treatment. Furthermore, as the novel FAE agent dimethylfumaric (DMF) ester (contained in BG00012/Panaclar) has previously been shown to be effective in psoriasis in a phase III trial and not shown renal toxicity in a large trial for multiple sclerosis, the current report suggests that market introduction of DMF for psoriasis should be pursued.

  17. Determining Phthalic Acid Esters Using Terahertz Time Domain Spectroscopy

    Science.gov (United States)

    Liu, L.; Shen, L.; Yang, F.; Han, F.; Hu, P.; Song, M.

    2016-09-01

    In this report terahertz time domain spectroscopy (THz-TDS) is applied for determining phthalic acid esters (PAEs) in standard materials. We reported the THz transmission spectrum in the frequency range of 0.2 to 2.0 THz for three PAEs: di-n-butyl phthalate (DBP), di-isononyl phthalate (DINP), and di-2-ethylhexyl phthalate ester (DEHP). The study provided the refractive indices and absorption features of these materials. The absorption spectra of three PAEs were simulated by using Gaussian software with Density Functional Theory (DFT) methods. For pure standard PAEs, the values of the refractive indices changed between 1.50 and 1.60. At 1.0 THz, the refractive indices were 1.524, 1.535, and 1.563 for DINP, DEHP, and DBP, respectively. In this experiment different concentrations of DBP were investigated using THz-TDS. Changes were measured in the low THz frequency range for refractive indices and characteristic absorption. The results indicated that THz-TDS is promising as a new method in determining PAEs in many materials. The results of this study could be used to support the practical application of THz-TDS in quality detection and food monitoring. In particular, this new technique could be used in detecting hazardous materials and other substances present in wine or foods.

  18. Physicochemical and electrochemical characterization of battery separator prepared by radiation induced grafting of acrylic acid onto microporous polypropylene membranes

    Directory of Open Access Journals (Sweden)

    2009-05-01

    Full Text Available Mutual radiation grafting technique was used to graft acrylic acid on micrometer thick micro-porous polypropylene membrane using high-energy gamma radiation. Grafting could not be achieved in aqueous acrylic acid solution. The presence of Mohr’s salt effectively retarded the homopolymerization of acrylic acid but did not lead to grafting enhancement. Mohr’s salt in presence of acids was found to be effective in enhancing the grafting yield. Contact angle measurement studies of the grafted and radiation treated polypropylene showed that initial grafting as well as radiation treatment of poly(propylene in aqueous medium and in presence of Mohr’s salt enhances its affinity towards the grafting solution. The enhancement in the polar component of surface energy of treated polypropylene membrane is the primary cause of grafting enhancement. The membranes grafted to an extent of ~20% were found to perform comparably with the battery separator presently being used by battery industry.

  19. Pluronic-poly (acrylic acid)-cysteine/Pluronic L121 mixed micelles improve the oral bioavailability of paclitaxel.

    Science.gov (United States)

    Zhao, Yanli; Li, Yanli; Ge, Jianjun; Li, Na; Li, Ling-Bing

    2014-11-01

    The aim of the study is to synthesize a thiolated Pluronic copolymer, Pluronic-poly (acrylic acid)-cysteine copolymer, to construct a mixed micelle system with the Pluronic-poly (acrylic acid)-cysteine copolymer and Pluronic L121 (PL121) and to evaluate the potential of these mixed micelles as an oral drug delivery system for paclitaxel. Compared with Pluronic-poly (acrylic acid)-cysteine micelles, drug-loading capacity of Pluronic-poly (acrylic acid)-cysteine/PL121 mixed micelles was increased from 0.4 to 2.87%. In vitro release test indicated that Pluronic-poly (acrylic acid)-cysteine/PL121 mixed micelles exhibited a pH sensitivity. The permeability of drug-loaded micelles in the intestinal tract was studied with an in situ perfusion method in rats. The presence of verapamil and Pluronic both improved the intestinal permeability of paclitaxel, which further certified the inhibition effect of thiolated Pluronic on P-gp. In pharmacokinetic study, the area under the plasma concentration-time curve (AUC0→∞) of paclitaxel-loaded mixed micelles was four times greater than that of the paclitaxel solution (p cysteine/PL121 micelles were proven to be a potential oral drug delivery system for paclitaxel.

  20. Kinetically controlled synthesis of monoglyceryl esters from chiral and prochiral acids methyl esters catalyzed by immobilized Rhizomucor miehei lipase.

    Science.gov (United States)

    Acosta, Andreina; Filice, Marco; Fernandez-Lorente, Gloria; Palomo, Jose M; Guisan, Jose M

    2011-01-01

    Partial acylation of only one primary hydroxyl group of glycerol generates a chiral center at position 2. Rhizomucor miehei lipase (RML) catalyzes the kinetically controlled transesterification of different aromatic carboxylic acids methyl esters with glycerol. High synthetic yields of glyceryl esters (around 70-80%) were obtained even in the presence of significant concentrations of water (from 5% to 20%). After a long incubation of the reaction mixture in the presence of the biocatalyst only pure free acid was obtained. Other lipases (from Geobacillus thermocatenulatus and from Thermomyces lanuginose) also catalyzed similar kinetically controlled transesterifications although less efficiently. RML immobilized on Sepharose-Q showed a high activity and specificity, compared to the immobilization by other techniques, only producing monoglyceryl esters with all substrates. In particular, monoglyceryl-phenylmalonate product was synthesized in 82% overall yield and >99% diastereomeric excess at pH 7.0 and 37°C and 90% glycerol.

  1. Synthesis of carboxymethylcellulose/acrylic acid hydrogels with superabsorbent properties by radiation-initiated crosslinking

    Science.gov (United States)

    Fekete, Tamás; Borsa, Judit; Takács, Erzsébet; Wojnárovits, László

    2016-07-01

    Superabsorbent hydrogels were prepared by gamma irradiation from aqueous solutions of carboxymethylcellulose (CMC) and acrylic acid (AAc) with varying CMC:AAc ratio. By partially replacing the CMC with AAc the gelation increased and led to a higher gel fraction and lower water uptake. Moreover, the gelation required significantly milder synthesis conditions. Decreasing both the dose and the solute concentration in the presence of AAc led to gels with higher gel fraction and higher degree of swelling compared to pure CMC gels. Increasing the AAc content up to 10% proved to be very effective, while very high AAc content (over 50%) hindered the gelation process.

  2. Mechanical and Thermal Properties of Compression Molded Poly (acrylic acid) Salts with Multivalent Metal Ions

    OpenAIRE

    Gotoh, Y.; Ohkoshi, Y; Nagura, M

    1999-01-01

    Films of zinc, calcium and aluminum salts of poly (acrylic acid) (PAA) were prepared from their powdery salts by compression molding at 190_??_200°C, 600MPa for 0.5hr and their mechanical and thermal properties were investigated. From the results of the dynamic mechanical thermal analysis the storage modulus of each PAA salts exhibited about 20GPa at room temperature because of highly intermolecular crosslinking of PAA by metal ions. Modulus of PAA calcium salt was 7GPa even at 400°C, while m...

  3. Tribological study of a highly hydrolytically stable phenylboronic acid ester containing benzothiazolyl in mineral oil

    NARCIS (Netherlands)

    Li, Zhipeng; Li, Xiufeng; Zhang, Yawen; Ren, T.; Zhao, Yidong; Zeng, X.; Heide, van der E.

    2014-01-01

    A novel long chain alkyl phenylboronic acid ester containing heterocyclic compound, bis (1-(benzothiazol-2-ylthio) propan-2-yl)-4-dodecylphenylboronic acid ester (DBBMT), was synthesized and characterized. The hydrolytic stability of the DBBMT was evaluated and the results show that DBBMT is of outs

  4. 21 CFR 178.3450 - Esters of stearic and palmitic acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Esters of stearic and palmitic acids. 178.3450 Section 178.3450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... SANITIZERS Certain Adjuvants and Production Aids § 178.3450 Esters of stearic and palmitic acids. The...

  5. Synthesis and Characteristics of an Aspartame Analogue, L-Asparaginyl L-3-Phenyllactic Acid Methyl Ester

    Institute of Scientific and Technical Information of China (English)

    Hu TAO; Da-Fu CUI; You-Shang ZHANG

    2004-01-01

    An aspartame analogue,L-asparaginyl L-3-phenyllactic acid methyl ester was synthesized with aspartic acid replaced by asparagine and peptide bond replaced by ester bond.The aspartic acid of aspartame could be replaced by asparagine as reported in the literature.In this analogue,the hydrogen ofamide group could still form a hydrogen bond with the oxygen of ester bond and the ester bond was isosteric with peptide bond.However,the product was not sweet,showing that the peptide bond could not be replaced by ester bond.The peptide C-N bond behaves as a double bond that is not free to rotate and the C,O,N and H atoms are in the same plane.The replacement of peptide bond by ester bond destroyed the unique conformation of peptide bond,resulting in the loss of sweet taste.

  6. Aliphatic amidase of Rhodococcus rhodochrous PA-34: Purification, characterization and application in synthesis of acrylic acid.

    Science.gov (United States)

    Thakur, Neerja; Kumar, Vijay; Sharma, Nirmal Kant; Thakur, Shikha; Bhalla, Tek Chand

    2016-01-01

    An intracellular aliphatic amide degrading inducible amidase produced by Rhodococcus rhodochrous PA-34 was characterized and acrylic acid synthesis from acrylamide was carried out using whole cell amidase. A bioprocess was developed at 50 ml fed batch reaction using 400 mM acrylamide feeding at an interval of 30 min resulted in the production of 4 g acrylic acid with volumetric and catalytic productivity of 80 g/l and 19 g/g/h respectively. The amidase of this organism had molecular weight of 40 kDa and was purified to 8.5 fold with 8% yield. This enzyme was active within the temperature range of 30 to 60 °C, with optimum temperature 45 °C and pH 7.5. The Vmax, Km, and kcat of purified amidase were calculated as 250 U/mg protein, 4.5 mM, and 166 sec-1 for acrylamide. The enzyme showed tolerance to metal chelating agent (EDTA) and was strongly inhibited by heavy metal ions Hg2+, Ag2+, Cu2+ and Co2+. R. rhodochrous PA-34 amidase preferentially hydrolyzed small aliphatic toxic amide such as acrylamide. Thus, the amidase of R. rhodochrous PA-34 is promising biocatalyst for the synthesis of industrially important acids and biodegradation of toxic amides.

  7. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of); Lim, Yun Kyong; Kook, Joong-Ki [Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Cho, Dong-Lyun [School of Applied Chemical Engineering and Center for Functional Nano Fine Chemicals, Chonnam National University, Gwangju (Korea, Republic of); Kim, Byung Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of)

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH{sub 2} of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  8. pH- and Electro-Responsive Properties of Poly(acrylic acid) and Poly(acrylic acid)-block-poly(acrylic acid-grad-styrene) Brushes Studied by Quartz Crystal Microbalance with Dissipation Monitoring.

    Science.gov (United States)

    Borisova, O V; Billon, L; Richter, R P; Reimhult, E; Borisov, O V

    2015-07-14

    We report on the synthesis of novel pH- and electro-responsive polyelectrolyte brushes from a gold substrate by direct one-step nitroxide-mediated polymerization of acrylic acid (AA) or copolymerization of AA and styrene (S). In the latter case, amphiphilic brushes of block-gradient copolymers PAA-b-(PAA-grad-PS) comprising one PAA block and one block with the gradient sequence of AA and S were obtained. The block-gradient copolymers are initiated from the surface by the start of the PAA block. The brushes were characterized by XPS and ellipsometry. (1)H NMR confirmed the gradient sequence of the PAA-grad-PS copolymer block. The pH- and electro-responsive properties of the brushes were studied by quartz crystal microbalance with dissipation monitoring (QCM-D) in combination with electrochemistry. This method provides evidence of swelling of the PAA brushes proportional to the contour length of the chains at elevated pH, whereas the response functions of the block-gradient copolymers are more complex and point to intermolecular aggregation in the brush at low pH. Monitoring of the changes in resonance frequency and dissipation of the QCM-D also demonstrates that application of negative voltage to the substrate leads to swelling of the brush; application of a positive voltage provokes only a transient collapse of the brush in proportion to the applied voltage.

  9. Ferulic acid esters of glucosylglucose from Allium macrostemon Bunge.

    Science.gov (United States)

    Usui, Ayaka; Matsuo, Yosuke; Tanaka, Takashi; Ohshima, Kazusato; Fukuda, Shinji; Mine, Takara; Yakashiro, Ichiro; Ishimaru, Kanji

    2016-09-02

    Three new ferulic acid esters of glucosylglucose, 1-O-(E)-feruloyl-β-d-glucopyranosyl (1-2)-[β- d-glucopyranosyl (1-6)]-β-d-glucopyranose (allimacronoid A, 1), 1-O-(E)-feruloyl-{β-d-glucopyranosyl (1-4)-[β-d-glucopyranosyl (1-2)]}-[β- d-glucopyranosyl (1-6)]-β-d-glucopyranose (allimacronoid B, 2), and 1-O-(E)-feruloyl-{β-d-glucopyranosyl (1-6)-[β-d-glucopyranosyl (1-2)]}-[β- d-glucopyranosyl (1-6)]-β-d-glucopyranose (allimacronoid C, 3) were isolated together with tuberonoid A (4), from the leaves of Allium macrostemon Bunge. The chemical structures were elucidated based on the analyses of the spectroscopic and chemical data.

  10. Low Molecular Weight PEI-Based Vectors via Acid-Labile Ortho Ester Linkage for Improved Gene Delivery.

    Science.gov (United States)

    Zhang, Lei; Yu, Min; Wang, Jun; Tang, Rupei; Yan, Guoqing; Yao, Weijing; Wang, Xin

    2016-08-01

    A series of novel pH-sensitive gene delivery vectors (POEI 1, 2, and 3) are synthesized through Michael addition from low molecular weight PEI (LMW PEI) via acid-labile ortho ester linkage with terminal acrylates (OEAc) by various feed molar ratios. The obtained POEI 1 and POEI 2 can efficiently condense plasmid DNA into nanoparticles with size range of 200-300 nm and zeta-potentials of about +15 mV while protecting DNA from enzymatic digestion compared with POEI 3. Significantly, ortho ester groups of POEI main-chains can make an instantaneous degradation-response to acidic endosomal pH (≈5.0), resulting in accelerated disruption of polyplexes and intracellular DNA release. MTT assay reveals that all POEIs exhibit much lower cytotoxicity in different cells than branched PEI (25 KDa). As expected, POEI 1 and POEI 2 perform improved gene transfection in vitro, suggesting that such polycations might be promising gene vectors based on overcoming toxicity-efficiency contradiction.

  11. Preparation and characterization of polyacrylamide-modified kaolinite containing poly [acrylic acid-co-methylene bisacrylamide] nanocomposite hydrogels

    DEFF Research Database (Denmark)

    Zaharia, Anamaria; Sarbu, Andrei; Radu, Anita-Laura;

    2015-01-01

    Novel nanocomposite hydrogel structures based on cross-linked poly(acrylic acid) (PAA) and kaolinite (Kaol), modified with different loadings of polyacrylamide (PAAm), were prepared by inverse dispersion polymerization. Ceric ammonium nitrate as an initiator in the presence of nitric acid was used...

  12. Synthesis of new fatty acids amides from aminolysis of fatty acid methyl esters (FAMEs); Sintese de novas amidas graxas a partir da aminolise de esteres metilicos

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Carolina R.; Montes D' Oca, Caroline da Ros; Duarte, Rodrigo da C.; Kurz, Marcia H.S.; Primel, Ednei G.; Clementin, Rosilene M.; Villarreyes, Joaquin Ariel M.; Montes D' Oca, Marcelo G., E-mail: dqmdoca@furg.b [Universidade Federal do Rio Grande, RS (Brazil). Escola de Quimica e Alimentos

    2010-07-01

    Recent biochemical and pharmacological studies have led to the characterization of different fatty acid amides as a new family of biologically active lipids. Here, we describe the synthesis of new amides from C16:0, 18:0, 18:1 and 18:1, OH fatty acids (FFA) families with cyclic and acyclic amines and demonstrate for the first time that these compounds produce cytotoxic effects. Application of this method to the synthesis of fatty acid amides was performed using the esters aminolysis as a key step and various carboxylic amides were prepared in good yield from fatty acid methyl esters (FAMEs). (author)

  13. Acrylic acid grafted cellulosic Luffa cylindrical fiber for the removal of dye and metal ions.

    Science.gov (United States)

    Gupta, Vinod Kumar; Agarwal, Shilpi; Singh, Prerna; Pathania, Deepak

    2013-10-15

    Acrylic acid grafted cellulosic Luffa cylindrical fiber was utilized for the removal of methylene blue and metal ions from the water system using batch process. The grafted sample used was found to demonstrate a maximum grafting efficiency of 90.8% under concentrations of 0.432×10(-3) mol/L, temperature of 35 °C, time of 60 min and pH of 7.0 respectively. The remarkable improvement in thermal properties of the grafted sample was observed. The formation of new bands in FTIR spectra of grafted sample confirmed the grafting of acrylic acid onto the cellulosic fiber. The maximum adsorption capacity of dye onto adsorbent was observed to be 62.15 mg g(-1) at 175 min. A maximum removal of 45.8% was observed for Mg(2+) as compared to other metal ions. High values of correlation coefficient for methylene blue (0.995) and metal ions such as Mg(2+) (0.996), Ni(2+) (0.995), Zn(2+) (0.996) confirmed the applicability of Langmuir isotherm that assumed a monolayer coverage and uniform activity distribution on the adsorbent surface.

  14. Protein absorption and fouling on poly(acrylic acid)-graft-polypropylene microfiltration membrane

    Science.gov (United States)

    Liu, Yanjun; Ma, Huiying; Lv, Chunying; Yang, Jia; Fu, Xueqi

    2009-07-01

    A series of pH-sensitive poly (acrylic acid)-graft-polypropylene hollow fiber microfiltration membranes were prepared by UV-photo-irradiation. Bovine serum albumin (BSA) was chosen as the model protein to investigate its absorption and fouling behaviors on membranes. The results showed that the hydrophilicity of grafted membrane was improved by poly(acrylic acid) chains with parts of membrane pores blocked. The grafted membranes were markedly pH-dependent on the water permeability as pH was altered from 1 to 11. The zeta potential of grafted membranes calculated by streaming potential was negative in most pH range. Electrostatic interaction energy calculated by DLVO theory showed the electric interaction force between grafted membrane and BSA was attractive. With the rise of grafting degree, the electric attractive force between grafted membrane and BSA increased as pH=3 and decreased as pH=8, while it kept basically unchanged as pH=4.7. As a result, most serious fouling was observed as pH=4.7. Grafted membranes had a lower BSA absorption and better antifouling behavior as pH=8, while the opposite result was revealed as pH=3. In conclusion, the absorption and fouling behavior of BSA on membranes was pH-dependent due to the pH-dependence of membrane charge, and the conformation of BSA and grafting chains.

  15. Rheology and adhesion of poly(acrylic acid)/laponite nanocomposite hydrogels as biocompatible adhesives.

    Science.gov (United States)

    Shen, Muxian; Li, Li; Sun, Yimin; Xu, Jun; Guo, Xuhong; Prud'homme, Robert K

    2014-02-18

    Biocompatible nanocomposite hydrogels (NC gels) consisting of poly(acrylic acid) (PAA) and nanosized clay (Laponite) were successfully synthesized by in situ free-radical polymerization of acrylic acid (AA) in aqueous solutions of Laponite. The obtained NC gels were uniform and transparent. Their viscosity, storage modulus G', and loss modulus G″ increased significantly upon increasing the content of Laponite and the dose of AA, while exhibiting a maximum with increasing the neutralization degree of AA. They showed tunable adhesion by changing the dose of Laponite and monomer as well as the neutralization degree of AA, as determined by 180° peel strength measurement. The maximal adhesion was shown when reaching a balance between cohesion and fluidity. A homemade Johnson-Kendall-Roberts (JKR) instrument was employed to study the surface adhesion behavior of the NC gels. The combination of peel strength, rheology, and JKR measurements offers the opportunity of insight into the mechanism of adhesion of hydrogels. The NC gels with tunable adhesion should be ideal candidates for dental adhesive, wound dressing, and tissue engineering.

  16. Graft Polymerization of Acrylic Acid and Acrylamide onto BOPET Corona Films

    Institute of Scientific and Technical Information of China (English)

    SUN Jie; TIAN Hua-yu; BAI Yong-ping

    2004-01-01

    The graft polymerization of acrylic acid ( A ) and acrylamide (B) was carried out onto bi- ori ented polyester BOPET corona film. The influence of monomer concentration, reducer concentration and reaction time on the graft polymerization was investigated. The surface tension of the films increased with an increase of monomer concentration, till the concentration of monomer A reached 1.5 × 10-2 g/mL and the concentration of monomer B reached 4.0× 10-2 g/ mL. The surface tension of the films reached a maximum value at 7 × 10 4 M of reducer concentration and subsequently decreased with further increase in reducer concentration. The surface tension of the films increased with the increase of the reaction time apparently within 50min. The grafted corona BO PET films were characterized with IR and XPS. The presence of graft on the film surface was confirmed. The atten uation experiments on grafted corona BOPET films in air at 50℃ and in water were carried out to investigate the persistence of graft polymerization of acrylic acid and arylamide onto BOPET corona films.

  17. Influence of Glyoxal on Preparation of Poly(Vinyl Alcohol)/Poly(Acrylic Acid) Blend Film.

    Science.gov (United States)

    Park, Ju-Young; Hwang, Kyung-Jun; Yoon, Soon-Do; Lee, Ju-Heon; Lee, In-Hwa

    2015-08-01

    The preparation of a poly(vinyl alcohol)/poly(acrylic acid)/glyoxal film (PVA = poly(vinyl alcohol); PAA = poly(acrylic acid)) with high tensile strength and hydrophobic properties by using the crosslinking reaction for OH group removal is reported herein. PAA was selected as a crosslinking agent because the functional carboxyl group in each monomer unit facilitates reaction with PVA. The OH groups on unreacted PVA were removed by the addition of glyoxal to the PVA/PAA solution. The chemical properties of the PVA/PAA films were investigated using Fourier transformation infrared spectroscopy and the thermal properties of the PVA/PAA/glyoxal films were investigated by means of differential scanning calorimetry and thermogravimetric analysis. A tensile strength of 48.6 N/mm2 was achieved at a PVA/PAA ratio of 85/15 for the PVA/PAA film. The tensile strength of the cross-linked PVA/PAA/glyoxal film (10 wt% glyoxal) was increased by 55% relative to the pure PVA/PAA (85/15) film. The degree of swelling (DS) and solubility (S) of the 10 wt% (PVA/PAA = 85/15, wt%) film added 10 wt% glyoxal were 1.54 and 0.6, respectively.

  18. Development of thiolated poly(acrylic acid) microparticles for the nasal administration of exenatide.

    Science.gov (United States)

    Millotti, Gioconda; Vetter, Anja; Leithner, Katharina; Sarti, Federica; Shahnaz Bano, Gul; Augustijns, Patrick; Bernkop-Schnürch, Andreas

    2014-12-01

    The purpose of this study was to develop a microparticulate formulation for nasal delivery of exenatide utilizing a thiolated polymer. Poly(acrylic acid)-cysteine (PAA-cys) and unmodified PAA microparticles loaded with exenatide were prepared via coprecipitation of the drug and the polymer followed by micronization. Particle size, drug load and release of incorporated exenatide were evaluated. Permeation enhancing properties of the formulations were investigated on excised porcine respiratory mucosa. The viability of the mucosa was investigated by histological studies. Furthermore, ciliary beat frequency (CBF) studies were performed. Microparticles displayed a mean size of 70-80 µm. Drug encapsulation was ∼80% for both thiolated and non-thiolated microparticles. Exenatide was released from both thiolated and non-thiolated particles in comparison to exenatide in buffer only within 40 min. As compared to exenatide dissolved in buffer only, non-thiolated and thiolated microparticles resulted in a 2.6- and 4.7-fold uptake, respectively. Histological studies performed before and after permeation studies showed that the mucosa is not damaged during permeation studies. CBF studies showed that the formulations were cilio-friendly. Based on these results, poly(acrylic acid)-cysteine-based microparticles seem to be a promising approach starting point for the nasal delivery of exenatide.

  19. Radiation synthesis of chitosan beads grafted with acrylic acid for metal ions sorption

    Energy Technology Data Exchange (ETDEWEB)

    Benamer, S., E-mail: benamers@yahoo.fr [Division of Nuclear Applications, Centre de Recherche Nucleaire d' Alger, BP-399 Alger-Gare (Algeria); Mahlous, M.; Tahtat, D.; Nacer-Khodja, A.; Arabi, M. [Division of Nuclear Applications, Centre de Recherche Nucleaire d' Alger, BP-399 Alger-Gare (Algeria); Lounici, H.; Mameri, N. [Ecole Nationale Polytechnique d' El-Harrach Alger (Algeria)

    2011-12-15

    Radiation-induced grafting of acrylic acid onto chitosan beads was performed in solution at a dose rate of 20.6 Gy/min of cobalt-60 gamma rays. The effect of absorbed dose on grafting yield was investigated. The characterization of the grafted material was performed by FTIR spectroscopy and the swelling measurements at different pHs. The grafting yield increased with the increase in dose, it reached 80% at 40 kGy irradiation dose. The removal of Pb and Cd ions from aqueous solutions was investigated with both ungrafted and grafted chitosan beads. The sorption behavior of the sorbents was examined through pH, kinetics and equilibrium measurements. Grafted chitosan beads presented higher sorption capacity for both metal ions than unmodified chitosan beads. - Highlights: > Pb and Cd ions are removed from aqueous solution by adsorption on chitosan beads. > Crosslinking process improves chemical stability of chitosan beads. > Radiation grafting of acrylic acid onto chitosan improves its metal adsorption capacity. > Increase in grafting degree enhances the adsorption capacity of the material. > Gamma radiation is a powerful tool for an accurate control of the grafting yield.

  20. Lewis acid promoted ruthenium(II)-catalyzed etherifications by selective hydrogenation of carboxylic acids/esters.

    Science.gov (United States)

    Li, Yuehui; Topf, Christoph; Cui, Xinjiang; Junge, Kathrin; Beller, Matthias

    2015-04-20

    Ethers are of fundamental importance in organic chemistry and they are an integral part of valuable flavors, fragrances, and numerous bioactive compounds. In general, the reduction of esters constitutes the most straightforward preparation of ethers. Unfortunately, this transformation requires large amounts of metal hydrides. Presented herein is a bifunctional catalyst system, consisting of Ru/phosphine complex and aluminum triflate, which allows selective synthesis of ethers by hydrogenation of esters or carboxylic acids. Different lactones were reduced in good yields to the desired products. Even challenging aromatic and aliphatic esters were reduced to the desired products. Notably, the in situ formed catalyst can be reused several times without any significant loss of activity.

  1. Occurrence of fatty acid esters of 3-MCPD, 2-MCPD and glycidol in infant formula.

    Science.gov (United States)

    Wöhrlin, Friederike; Fry, Hildburg; Lahrssen-Wiederholt, Monika; Preiß-Weigert, Angelika

    2015-01-01

    The discovery of fatty acid esters of monochloropropanediol (MCPD) and glycidol generated during the refinement process in vegetable fats and oils caused concerns about possible adverse health effects. As these fats are components of infant formula, the current investigation of the MCPD and glycidyl ester contents in infant formula was necessary to update the data for risk assessment purposes. For the analysis of 3-MCPD, 2-MCPD and glycidyl esters in infant formula, an existing method for fats and oils had to be modified and validated. The fat fraction containing MCPD and glycidyl esters was extracted from infant formula by accelerated solvent extraction (ASE). The extracted fat was then analysed according to an established method for fats and oils. Glycidyl esters are converted to monobrompropanediol (3-MBPD) esters, MCPD and 3-MBPD esters hydrolysed subsequently and after derivatisation detected by GC-MS. Seven different products of infant formula, covering two types and five lots each, altogether 70 samples, were bought in retail markets and analysed. In all samples, 3-MCPD and glycidyl esters could be detected. Both 3-MCPD and glycidyl esters' concentration levels were found to be lower in comparison with earlier investigations described in the literature. The occurrence of 2-MCPD esters in infant formula was investigated for the first time and revealed concentrations about half of 3-MCPD ester concentrations.

  2. 75 FR 50926 - 2-propenoic acid, 2-methyl-, C12-16-alkyl esters, telomers with 1-dodecanethiol, polyethylene...

    Science.gov (United States)

    2010-08-18

    ... AGENCY 40 CFR Part 180 2-propenoic acid, 2-methyl-, C12-16-alkyl esters, telomers with 1-dodecanethiol... tolerance for residues of 2-propenoic acid, 2-methyl-, C12-16- alkyl esters, telomers with 1-dodecanethiol... residues of 2-propenoic acid, 2-methyl-, C12-16-alkyl esters, telomers with 1-dodecanethiol,...

  3. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl polycarboxylic acids, esters... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  4. 40 CFR 721.6100 - Phosphoric acid, C6-12-alkyl esters, compounds with 2-(dibutylamino) ethanol.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphoric acid, C6-12-alkyl esters... Significant New Uses for Specific Chemical Substances § 721.6100 Phosphoric acid, C6-12-alkyl esters... reporting. (1) The chemical substances identified as phosphoric acid, C6-12-alkyl esters, compounds with...

  5. 75 FR 70254 - Typographical Error in Summary Notice of Filing in Docket for Polymerized Fatty Acid Esters With...

    Science.gov (United States)

    2010-11-17

    ... AGENCY Typographical Error in Summary Notice of Filing in Docket for Polymerized Fatty Acid Esters With...), concerning the Notice of Filing (NOF) for Pesticide Petition (PP) 0E7699 for polymerized fatty acid esters... Notice of Filing (NOF) for Pesticide Petition (PP) 0E7699 for polymerized fatty acid esters...

  6. 75 FR 4292 - 2-Propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene and 2-methylpropyl 2-methyl-2...

    Science.gov (United States)

    2010-01-27

    ... AGENCY 40 CFR Part 180 2-Propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene and 2... residues of 2-propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene and 2-methylpropyl 2-methyl-2... permissible level for residues of 2-propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene and...

  7. 75 FR 20785 - Polyglyceryl Phthalate Ester of Coconut Oil Fatty Acids; Exemption from the Requirement of a...

    Science.gov (United States)

    2010-04-21

    ... AGENCY 40 CFR Part 180 Polyglyceryl Phthalate Ester of Coconut Oil Fatty Acids; Exemption from the..., concerning polyglyceryl phthalate ester of coconut oil fatty acids; exemption from the requirement of a... phthalate ester of coconut oil fatty acids'' pursuant to a petition by the Joint Inserts Task Force,...

  8. 40 CFR 721.3100 - Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Oligomeric silicic acid ester compound... Significant New Uses for Specific Chemical Substances § 721.3100 Oligomeric silicic acid ester compound with a... chemical substance identified generically as oligomeric silicic acid ester compound with...

  9. 40 CFR 721.304 - Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1-methyl hexyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acetic acid, , 1-methyl hexyl ester... Substances § 721.304 Acetic acid, , 1-methyl hexyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as acetic acid, -, 1-methylhexyl ester (PMN...

  10. Relative oral bioavailability of glycidol from glycidyl fatty acid esters in rats.

    Science.gov (United States)

    Appel, Klaus E; Abraham, Klaus; Berger-Preiss, Edith; Hansen, Tanja; Apel, Elisabeth; Schuchardt, Sven; Vogt, Carla; Bakhiya, Nadiya; Creutzenberg, Otto; Lampen, Alfonso

    2013-09-01

    In order to quantify the relative bioavailability of glycidol from glycidyl fatty acid esters in vivo, glycidyl palmitoyl ester and glycidol were orally applied to rats in equimolar doses. The time courses of the amounts of glycidol binding to hemoglobin as well as the excretion of 2,3-dihydroxypropyl mercapturic acids were determined. The results indicate that glycidol is released from the glycidyl ester by hydrolysis and rapidly distributed in the organism. In relation to glycidol, there was only a small timely delay in the binding to hemoglobin for the glycidol moiety released from the ester which may be certainly attributed to enzymatic hydrolysis. In both cases, however, an analogous plateau was observed representing similar amounts of hemoglobin binding. With regard to the urinary excretion of mercapturic acids, also similar amounts of dihydroxypropyl mercapturic acids could be detected. In an ADME test using a virtual double tag (³H, ¹⁴C) of glycidyl palmitoyl ester, a diverging isotope distribution was detected. The kinetics of the ¹⁴C-activity reflected the kinetics of free glycidol released after hydrolysis of the palmitoyl ester. In view of this experimental data obtained in rats, it is at present justified for the purpose of risk assessment to assume complete hydrolysis of the glycidyl ester in the gastrointestinal tract. Therefore, assessment of human exposure to glycidyl fatty acid ester should be regarded as an exposure to the same molar quantity of glycidol.

  11. ABS polymer electroless plating through a one-step poly(acrylic acid) covalent grafting.

    Science.gov (United States)

    Garcia, Alexandre; Berthelot, Thomas; Viel, Pascal; Mesnage, Alice; Jégou, Pascale; Nekelson, Fabien; Roussel, Sébastien; Palacin, Serge

    2010-04-01

    A new, efficient, palladium- and chromium-free process for the electroless plating of acrylonitrile-butadiene-styrene (ABS) polymers has been developed. The process is based on the ion-exchange properties of poly(acrylic acid) (PAA) chemically grafted onto ABS via a simple and one-step method that prevents using classical surface conditioning. Hence, ABS electroless plating can be obtained in three steps, namely: (i) the grafting of PAA onto ABS, (ii) the copper Cu(0) seeding of the ABS surface, and (iii) the nickel or copper metallization using commercial-like electroless plating bath. IR, XPS, and SEM were used to characterize each step of the process, and the Cu loading was quantified by atomic absorption spectroscopy. This process successfully compares with the commercial one based on chromic acid etching and palladium-based seed layer, because the final metallic layer showed excellent adhesion with the ABS substrate.

  12. Peptide immobilization onto radiation grafted PVDF-g-poly(acrylic acid) films

    Science.gov (United States)

    Clochard, M.-C.; Betz, N.; Goncalves, M.; Bittencourt, C.; Pireaux, J.-J.; Gionnet, K.; Déléris, G.; Moël, A. Le

    2005-07-01

    Introducing hydrophilic functions on poly(vinylidene fluoride) (PVDF) films surface allows the covalent immobilization of peptides. Therefore radiation grafting of acrylic acid (AA) in pre-irradiated PVDF films was achieved to allow surface functionalization with linear and cyclic peptides. Peptides were bound via spacer molecules using EDC as a coupling agent. The reactions were followed by Fourier Transform Infrared (FTIR) spectroscopy in attenuated total reflection (ATR) mode. The amount of immobilized peptides was determined by UV spectroscopy. As well, an uncommon method for PVDF characterization and reactions quantification was used: high-resolution-magic angle spinning nuclear mass spectroscopy (HR-MAS NMR). Spacer saturation of the film surface corresponded to 25 mol% yield meaning that one spacer on 4 carboxylic acids was covalently bound. XPS experiments were also performed to deepen analysis of the surface composition. Peptide density is governed by steric hindrance. ELISA tests showed that the peptides' activity is maintained.

  13. Poly(acrylic acid)-grafted graphene oxide as an intracellular protein carrier.

    Science.gov (United States)

    Kavitha, Thangavelu; Kang, Inn-Kyu; Park, Soo-Young

    2014-01-14

    A pH-sensitive poly(acrylic acid)-grafted graphene oxide (GO-PAA) nanocarrier was synthesized by in situ atom transfer radical polymerization to allow the oral delivery of hydrophilic macromolecular proteins in their active forms to specific cells or organs. The synthesis, morphology, and physiochemical properties of GO-PAA were examined. A model protein, bovine serum albumin (BSA) labeled with fluorescein isothiocyanate (FITC) (BSAFITC), was loaded onto GO-PAA through noncovalent interactions and its release was arrested at acidic pH similar to stomach, whereas at pH similar to intestine it was reduced, which paves way for site specific delivery without its degradation in the gastrointestinal tract. Confocal laser microscopy showed that the BSAFITC-loaded GO-PAA was internalized by KB cells by endocytosis and released into cytoplasm. Thus the GO-PAA as a transmembrane transporter is a new class of drug transporters with potential protein delivery applications.

  14. Pseudo catalytic transformation of volatile fatty acids into fatty acid methyl esters.

    Science.gov (United States)

    Jung, Jong-Min; Cho, Jinwoo; Kim, Ki-Hyun; Kwon, Eilhann E

    2016-03-01

    Instead of anaerobic digestion of biodegradable wastes for producing methane, this work introduced the transformation of acidogenesis products (VFAs) into fatty acid methyl esters (FAMEs) to validate the feasible production of short-chained fatty alcohols via hydrogenation of FAMEs. In particular, among VFAs, this work mainly described the mechanistic explanations for transforming butyric acid into butyric acid methyl ester as a case study. Unlike the conventional esterification process (conversion efficiency of ∼94%), the newly introduced esterification under the presence of porous materials via the thermo-chemical process reached up to ∼99.5%. Furthermore, the newly introduced esterification via the thermo-chemical pathway in this work showed extremely high tolerance of impurities: the conversion efficiency under the presence of impurities reached up to ∼99±0.3%; thus, the inhibition behaviors attributed from the impurities used for the experimental work were negligible.

  15. Metabolism of hydroxycinnamic acids and esters by Brettanomyces in different red wines

    Science.gov (United States)

    Depending on the cultivars and other factors, differing concentrations of hydroxycinnamic acids (caffeic, p-coumaric, and ferulic acids) and their corresponding tartaric acid esters (caftaric, coutaric, and fertaric acid, respectively) are found in red wines. Hydroxycinnamic acids are metabolized by...

  16. Synthesis of some glucose-fatty acid esters by lipase from Candida antarctica and their emulsion functions.

    Science.gov (United States)

    Ren, Kangzi; Lamsal, Buddhi P

    2017-01-01

    The synthesis of glucose esters with palmitic acid, lauric acid and hexanoic acid using lipase enzyme was studied and their emulsion functionality in oil-in-water system were compared. Reactions at 3:1M ratio of fatty acids-to-glucose had the highest conversion percentages (over 90% for each of the fatty acid). Initial conversion rate increased as substrate solubility increased. Ester bond formation was confirmed by nuclear magnetic resonance technique that the chemical shifts of glucose H-6 and α-carbon protons of fatty acids in the ester molecules shifted to the higher fields. Contact angle of water on esters' pelleted surface increased as the hydrophobicity increased. Glucose esters' and commercial sucrose esters' functionality as emulsifiers were compared. Glucose esters delayed, but did not prevent coalescence, because the oil droplets diameter doubled during 7days. Sucrose esters prevented coalescence during 7days since the droplets diameter did not have significant change.

  17. UV-induced graft polymerization of acrylic acid in the sub-micronchannels of oxidized PET track-etched membrane

    Energy Technology Data Exchange (ETDEWEB)

    Korolkov, Ilya V.; Mashentseva, Anastassiya A. [The L.N. Gumilyov Eurasian National University, Satpayev str., 2, 010008 Astana (Kazakhstan); Institute of Nuclear Physics Republic of Kazakhstan, 050032, Ibragimov str., 1, Almaty (Kazakhstan); Güven, Olgun [Department of Chemistry, Hacettepe University, 06800 Beytepe, Ankara (Turkey); Taltenov, Abzal A. [The L.N. Gumilyov Eurasian National University, Satpayev str., 2, 010008 Astana (Kazakhstan)

    2015-12-15

    In this article, we report on functionalization of track-etched membrane based on poly(ethylene terephthalate) (PET TeMs) oxidized by advanced oxidation systems and by grafting of acrylic acid using photochemical initiation technique for the purpose of increasing functionality thus expanding its practical application. Among advanced oxidation processes (H{sub 2}O{sub 2}/UV) system had been chosen to introduce maximum concentration of carboxylic acid groups. Benzophenone (BP) photo-initiator was first immobilized on the surfaces of cylindrical pores which were later filled with aq. acrylic acid solution. UV-irradiation from both sides of PET TeMs has led to the formation of grafted poly(acrylic acid) (PAA) chains inside the membrane sub-micronchannels. Effect of oxygen-rich surface of PET TeMs on BP adsorption and subsequent process of photo-induced graft polymerization of acrylic acid (AA) were studied by ESR. The surface of oxidized and AA grafted PET TeMs was characterized by UV–vis, ATR-FTIR, XPS spectroscopies and by SEM.

  18. Preparation and drug-loading properties of Fe3O4/Poly(styrene-co-acrylic acid) magnetic polymer nanocomposites

    Science.gov (United States)

    Lu, Wensheng; Shen, Yuhua; Xie, Anjian; Zhang, Weiqiang

    2013-11-01

    Fe3O4/poly(styrene-co-acrylic acid) magnetic polymer nanocomposites were synthesized by the dispersion polymerization method using styrene as hard monomer, acrylic acid as functional monomer, Fe3O4 nanoparticles modified with oleic acid as core, and poly(styrene-co-acrylic acid) as shell. Drug-loading properties of magnetic polymer nanocomposites with curcumin as a model drug were also studied. The results indicated that magnetic polymer nanocomposites with monodisperse were obtained, the particle size distribution was 50-120 nm, and the average size was about 100 nm. The contents of poly(styrene-co-acrylic acid) and Fe3O4 nanoparticles in magnetic polymer nanocomposites were 74% and 24.7%, respectively. The drug-loading capacity and entrapment efficiency were 2.5% and 44.4%, respectively. The saturation magnetization of magnetic polymer nanocomposites at 300 K was 20.2 emu/g without coercivity and remanence. The as-prepared magnetic polymer nanocomposites have not only lots of functional carboxyl groups but also stronger magnetic response, which might have potential applications in drug carrier and targeted drug release.

  19. Sugar fatty acid esters inhibit biofilm formation by food-borne pathogenic bacteria.

    Science.gov (United States)

    Furukawa, Soichi; Akiyoshi, Yuko; O'Toole, George A; Ogihara, Hirokazu; Morinaga, Yasushi

    2010-03-31

    Effects of food additives on biofilm formation by food-borne pathogenic bacteria were investigated. Thirty-three potential food additives and 3 related compounds were added to the culture medium at concentrations from 0.001 to 0.1% (w/w), followed by inoculation and cultivation of five biofilm-forming bacterial strains for the evaluation of biofilm formation. Among the tested food additives, 21 showed inhibitory effects of biofilm formation by Staphylococcus aureus and Escherichia coli, and in particular, sugar fatty acid esters showed significant anti-biofilm activity. Sugar fatty acid esters with long chain fatty acid residues (C14-16) exerted their inhibitory effect at the concentration of 0.001% (w/w), but bacterial growth was not affected at this low concentration. Activities of the sugar fatty acid esters positively correlated with the increase of the chain length of the fatty acid residues. Sugar fatty acid esters inhibited the initial attachment of the S. aureus cells to the abiotic surface. Sugar fatty acid esters with long chain fatty acid residues (C14-16) also inhibited biofilm formation by Streptococcus mutans and Listeria monocytogenes at 0.01% (w/w), while the inhibition of biofilm formation by Pseudomonas aeruginosa required the addition of a far higher concentration (0.1% (w/w)) of the sugar fatty acid esters.

  20. Novel one-dimensional lanthanide acrylic acid complexes: an alternative chain constructed by hydrogen bonding

    Science.gov (United States)

    Li, Hui; Hu, Chang Wen

    2004-12-01

    Novel one-dimensional (1D) chains of three lanthanide complexes La(L 1) 3(CH 3OH)]·CH 3OH (L 1=(E)-3-(2-hydroxyl-phenyl)-acrylic acid) 1, La(L 2) 3(H 2O) 2]·2.75H 2O (L 2=(E)-3-(3-hydroxyl-phenyl)-acrylic acid) 2, and La(L 3) 3(CH 3OH) 2(H 2O)]·CH 3OH (L 3=(E)-3-(4-hydroxyl-phenyl)-acrylic acid) 3 are reported. The crystal structure data are as follows for 1: C 29H 29LaO 11, monoclinic, P2 1/ n, a=15.4289(12) Å, b=7.9585(6) Å, c=23.041(2) Å, β=99.657(2)°, Z=4, R1=0.0637, w R2=0.0919; for 2: C 27H 30.50LaO 13.75, triclinic, P-1, a=8.4719(17) Å, b=13.719(3) Å, c=14.570(3) Å, α=62.19(3)°, β=99.657(2)°, γ=78.22(3)°, Z=2, R1=0.0384, w R2=0.0820; and for 3: C 30H 35LaO 13, monoclinic, P2(1)/ c, a=9.5667(6) Å, b=24.3911(15) Å, c=14.0448(9) Å, β=109.245(2)°, Z=4, R1=0.0374, w R2=0.0630. All the three structure data were collected using graphite monochromated molybdenum Kα radiation and refined using full-matrix least-squares techniques on F 2. These structures show that four kinds of the carboxylato bridge modes are included in these chains to link the La(III) ions. It is the first time that it has been found that the intra-chain hydrogen bonding can construct an alternative chain even, when the coordination bridge mode is the same along the chain (complex 2). There are 2D and 3D hydrogen bonding in the crystal lattices of complexes 1- 3.

  1. Technological Aspects of Chemoenzymatic Epoxidation of Fatty Acids, Fatty Acid Esters and Vegetable Oils: A Review

    Directory of Open Access Journals (Sweden)

    Eugeniusz Milchert

    2015-12-01

    Full Text Available The general subject of the review is analysis of the effect of technological parameters on the chemoenzymatic epoxidation processes of vegetable oils, fatty acids and alkyl esters of fatty acids. The technological parameters considered include temperature, concentration, amount of hydrogen peroxide relative to the number of unsaturated bonds, the amounts of enzyme catalysts, presence of solvent and amount of free fatty acids. Also chemical reactions accompanying the technological processes are discussed together with different technological options and significance of the products obtained.

  2. Lipase catalyzed synthesis of organic acid esters of lactic acid in non-aqueous media.

    Science.gov (United States)

    Kiran, K R; Divakar, S

    2001-05-04

    Lipases from Rhizomucor miehei (Lipozyme IM20) and porcine pancreas (PPL) were employed as catalysts for the esterification reaction between the hydroxyl group of lactic acid and the carboxyl group of organic acids. Reactions were carried out at both shake-flask and bench-scale levels. Various parameters, such as solvent, temperature, substrate and enzyme concentrations, effect of buffer volume, buffer pH and water volume, were investigated for optimization of yields. While ethylmethyl ketone (EMK) was found to be the best solvent for shake-flask reactions, chloroform gave higher yields at bench-scale level. Detailed studies were carried out with respect to the synthesis of palmitoyl and stearoyl lactic acids. At shake-flask level, maximum yields of 37.5 and 40% were observed in case of palmitoyl and stearoyl lactic acids, respectively, with Lipozyme IM20; at bench-scale level, the maximum yields were 85.1 and 99% respectively, when PPL was employed. Of all the organic acids employed (C(2)--C(18)), only lauric, palmitic and stearic acids gave yields above 50%. At bench-scale level, PPL could be reused for up to three cycles with yields above 40%. Esters prepared were found to conform to Food Chemical Codex (FCC) specifications in terms of acid value, ester value, sodium and lactic acid contents.

  3. Photoinduced Graft-Polymerization of Acrylic Acid on Polyethylene and Polypropylene Surfaces: Comparative Study Using IR-ATR Spectroscopy

    Science.gov (United States)

    Gorbachev, A. A.; Tretinnikov, O. N.; Shkrabatovskaya, L. V.; Prikhodchenko, L. K.

    2014-11-01

    Photoinduced graft-polymerization of acrylic acid on the surface of polyethylene and polypropylene films containing a photoinitiator pre-adsorbed from a thin layer of non-de-aerated aqueous monomer solution was investigated. Data about the monomer conversion and grafting depth as functions of the UV irradiation time and polymer nature were obtained using IR-ATR spectroscopy.

  4. Comparison of various models to describe the charge-pH dependence of poly(acrylic acid)

    NARCIS (Netherlands)

    Lützenkirchen, J.; Male, van J.; Leermakers, F.A.M.; Sjöberg, S.

    2011-01-01

    The charge of poly(acrylic acid) (PAA) in dilute aqueous solutions depends on pH and ionic strength. We report new experimental data and test various models to describe the deprotonation of PAA in three different NaCl concentrations. A simple surface complexation approach is found to be very success

  5. On the effect of treating poly(acrylic acid) with argon and tetrafluoromethane plasmas: Kinetics and degradation mechanism

    NARCIS (Netherlands)

    Terlingen, Johannes G.A.; Takens, Gijsbert A.J.; Gaag, van der Frederik J.; Hoffman, Allan S.; Feijen, Jan

    1994-01-01

    Poly(acrylic acid) (PAAc) films were treated with either an argon or a tetrafluoromethane (CF4) plasma and subsequently analyzed with X-ray photoelectron spectroscopy (XPS). PAAc films were decarboxylated during both types of plasma treatments. In addition, during the CF4 plasma treatment, the PAAc

  6. Introduction of poly[(2-acryloyloxyethyl trimethyl ammonium chloride)-co-(acrylic acid)] branches onto starch for cotton warp sizing.

    Science.gov (United States)

    Shen, Shiqi; Zhu, Zhifeng; Liu, Fengdan

    2016-03-15

    An attempt has been made to reveal the effect of amphoteric poly(2-acryloyloxyethyl trimethyl ammonium chloride-co-acrylic acid) [P(ATAC-co-AA)] branches grafted onto the backbones of starch upon the adhesion-to-cotton, film properties, and desizability of maize starch for cotton warp sizing. Starch-g-poly[(2-acryloyloxyethyl trimethyl ammonium chloride)-co-(acrylic acid) [S-g-P(ATAC-co-AA)] was prepared by the graft copolymerization of 2-acryloyloxyethyl trimethyl ammonium chloride (ATAC) and acrylic acid (AA) with acid-converted starch (ACS) in aqueous medium using Fe(2+)-H2O2 initiator. The adhesion was evaluated in term of bonding strength according to the FZ/T 15001-2008 whereas the film properties considered included tensile strength, work and percentage elongation at break. The evaluation was undertaken through the comparison of S-g-P(ATAC-co-AA) with ACS, starch-g-poly(acrylic acid), and starch-g-poly(2-acryloyloxyethyl trimethyl ammonium chloride). It was found that the amphoteric branch was able to significantly improve the adhesion and mitigate the brittleness of starch film. Zeta potential of cooked S-g-P(ATAC-co-AA) paste, depending on the mole ratio of ATAC to AA units on P(ATAC-co-AA) branches, had substantial effect on the adhesion and desizability. Increasing the mole ratio raised the potential, which favored the adhesion but disfavored the removal of S-g-P(ATAC-co-AA) from sized cotton warps. Electroneutral S-g-P(ATAC-co-AA) was superior to negatively grafted starch in adhesion and to positively grafted starch in desizability. Generally, it showed better sizing property than ACS, starch-g-poly(acrylic acid), and starch-g-poly(2-acryloyloxyethyl trimethyl ammonium chloride), and had potential in the application of cotton warp sizing.

  7. Fatty acid alkyl esters: perspectives for production of alternative biofuels.

    Science.gov (United States)

    Röttig, Annika; Wenning, Leonie; Bröker, Daniel; Steinbüchel, Alexander

    2010-02-01

    The global economy heads for a severe energy crisis: whereas the energy demand is going to rise, easily accessible sources of crude oil are expected to be depleted in only 10-20 years. Since a serious decline of oil supply and an associated collapse of the economy might be reality very soon, alternative energies and also biofuels that replace fossil fuels must be established. In addition, these alternatives should not further impair the environment and climate. About 90% of the biofuel market is currently captured by bioethanol and biodiesel. Biodiesel is composed of fatty acid alkyl esters (FAAE) and can be synthesized by chemical, enzymatic, or in vivo catalysis mainly from renewable resources. Biodiesel is already established as it is compatible with the existing fuel infrastructure, non-toxic, and has superior combustion characteristics than fossil diesel; and in 2008, the global production was 12.2 million tons. The biotechnological production of FAAE from low cost and abundant feedstocks like biomass will enable an appreciable substitution of petroleum diesel. To overcome high costs for immobilized enzymes, the in vivo synthesis of FAAE using bacteria represents a promising approach. This article points to the potential of different FAAE as alternative biofuels, e.g., by comparing their fuel properties. In addition to conventional production processes, this review presents natural and genetically engineered biological systems capable of in vivo FAAE synthesis.

  8. Dielectric properties of solution-grown-undoped and acrylic-acid-doped ethyl cellulose

    Indian Academy of Sciences (India)

    P K Khare; Sandeep K Jain

    2000-02-01

    Dielectric capacities and losses were measured, in the temperature (50–170°C) and frequency (01–100 kHz range), for undoped and acrylic acid (AA) doped ethyl cellulose (EC) films (thickness about 20 m) with progressive increase in the concentration of dopant in the polymer matrix. The variation of capacity with temperature is attributed to thermal expansion in the lower temperature region to the orientation of dipolar molecules in the neighbourhood of glass transition temperature () and random thermal motion of molecules above . The dielectric losses exhibit a broad peak. Doping with AA is found to affect the magnitude and position of the peak. AA is found to have a two-fold action. Firstly, it enhances the chain mobility and secondly, it increases the dielectric loss by forming charge transfer complexes.

  9. Radiation-induced grafting of diallyldimethylammonium chloride onto acrylic acid grafted polyethylene

    Science.gov (United States)

    Francis, Sanju; Dhanawade, B. R.; Mitra, D.; Varshney, Lalit; Sabharwal, Sunil

    2009-01-01

    Diallyldimethylammonium chloride (DADMAC) was grafted onto polyethylene (PE) films by a double grafting procedure. The PE film was initially modified by grafting acrylic acid (AA), through a mutual irradiation method. AA-g-PE film, thus obtained was subjected to subsequent radiation grafting reaction of DADMAC, to give a DADMAC-g-AA-g-PE film having a comb-type structure. The influence of different conditions, such as the extent of AA grafting, DADMAC concentration, absorbed dose and dose rate, on the grafting yield of DADMAC was investigated. A maximum DADMAC grafting of 30% was achieved. The equilibrium degree of swelling (EDS) of the grafted films were gravimetrically determined. TGA and FT-IR techniques were employed to characterize the grafted PE films.

  10. Radiation-induced grafting of diallyldimethylammonium chloride onto acrylic acid grafted polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Sanju [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)], E-mail: sanju@barc.gov.in; Dhanawade, B.R.; Mitra, D.; Varshney, Lalit; Sabharwal, Sunil [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2009-01-15

    Diallyldimethylammonium chloride (DADMAC) was grafted onto polyethylene (PE) films by a double grafting procedure. The PE film was initially modified by grafting acrylic acid (AA), through a mutual irradiation method. AA-g-PE film, thus obtained was subjected to subsequent radiation grafting reaction of DADMAC, to give a DADMAC-g-AA-g-PE film having a comb-type structure. The influence of different conditions, such as the extent of AA grafting, DADMAC concentration, absorbed dose and dose rate, on the grafting yield of DADMAC was investigated. A maximum DADMAC grafting of 30% was achieved. The equilibrium degree of swelling (EDS) of the grafted films were gravimetrically determined. TGA and FT-IR techniques were employed to characterize the grafted PE films.

  11. Synthesis and characterization of zinc chloride containing poly(acrylic acid) hydrogel by gamma irradiation

    Science.gov (United States)

    Park, Jong-Seok; Kuang, Jia; Gwon, Hui-Jeong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Seob Khil, Myung; Nho, Young-Chang

    2013-07-01

    In this study, the characterization of zinc chloride incorporated into a poly(acrylic acid) (PAAc) hydrogel prepared by gamma-ray irradiation was investigated. Zinc chloride powder with different concentrations was dissolved in the PAAc solution, and it was crosslinked with gamma-ray irradiation. The effects of various parameters such as zinc ion concentration and irradiation doses on characteristics of the hydrogel formed were investigated in detail for obtaining an antibacterial wound dressing. In addition, the gel content, pH-sensitive (pH 4 or 7) swelling ratio, and UV-vis absorption spectra of the zinc particles in the hydrogels were characterized. Moreover, antibacterial properties of these new materials against Staphylococcus aureus and Escherichia coli strains were observed on solid growth media. The antibacterial tests indicated that the zinc chloride containing PAAc hydrogels have good antibacterial activity.

  12. Poly-Acrylic Acid Derivatives as Diesel Flow Improver for Paraffin-Based Daqing Diesel

    Institute of Scientific and Technical Information of China (English)

    Cuiyu Jiang; Ming Xu; Xiaoli Xi; Panlun Qi; Hongyan Shang

    2006-01-01

    Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant (PPDs) that resulted from the high content of paraffin, certain poly-acrylic acid derivatives (PADE) with-COOR,-COOH,-CONHR, and -COO-NH3+R groups by molecular design on the mechanics of diesel; PPDs were synthesized and evaluated as cold flow improver for Daqing 0# diesel in this paper. The pure PADE was superior to the commercial PPDs and displayed a substantial ability of wax crystals dispersion. There was a synergistic effect among the PADE and T1804 and secondary amine. The synergism clearly improved the low temperature performance of Daqing diesel products and could reduce the cold filter plugging point of 0# diesel by 6-7 ℃.

  13. Study on swelling behaviour of hydrogel based on acrylic acid and pectin from dragon fruit

    Science.gov (United States)

    Abdullah, Mohd Fadzlanor; Lazim, Azwani Mat

    2014-09-01

    Biocompatible hydrogel based on acrylic acid (AA) and pectin was synthesized using gamma irradiation technique. AA was grafted onto pectin backbone that was extracted from dragon fruit under pH 3.5 and extracts and ethanol ratios (ER) 1:0.5. The optimum hydrogel system with high swelling capacity was obtained by varying the dose of radiation and ratio of pectin:AA. FTIR-ATR spectroscopy was used to verify the interaction while thermal properties were analyzed by TGA and DSC. Swelling studies was carried out in aqueous solutions with different pH values as to determine the pH sensitivity. The results show that the hydrogel with a ratio of 2:3 (pectin:AA) and 30 kGy radiation dose has the highest swelling properties at pH of 10.

  14. Synthesis of A Novel Photosensitive Prepolymer with Trimethylolpropane Triglycidylether and Acrylic Acid as Starting Materials

    Institute of Scientific and Technical Information of China (English)

    HUANG Biwu; HUANG Shuhuai; SHI Yusheng; MO Jianhua

    2005-01-01

    A novel photosensitive prepolymer of trimethylolpropane triglycidylether triacrylate was synthesized by utilizing trimethylolpropane triglycidylether and acrylic acid as two starting materials, triphenyl phosphine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthesis conditions were that the concentration of triphenyl phosphine was 0.85wt% of reactants, the concentration of p-hydroxyanisole was 0.3wt% of reactants, and the reaction temperature was at 90-110 ℃. Benzil dimethyl ketal of a UV-cured initiator was added to the synthesized trimethylolpropane triglycidylether triacrylate to prepare a kind of UV-cured coating. The mechanical properties of the UV-cured films were determined, giving 28.43 MPa of tensile strength, 965.59MPa of Young's modulus and 4.10% of elongation at tear.

  15. Poly(acrylic acid) microspheres loaded with lidocaine: preparation and characterization for arterial embolization.

    Science.gov (United States)

    Cui, Dai-Chao; Lu, Wan-Liang; Sa, Er-A; Gu, Meng-Jie; Lu, Xiao-Jing; Fan, Tian-Yuan

    2012-10-15

    A new embolic agent, poly(acrylic acid) microspheres (PMs), was synthesized and the cytocompatibility was proved by mouse L929 fibroblast cells. An analgesic drug, lidocaine, was loaded on the PMs to relief pain caused by embolization. PMs and lidocaine loaded microspheres (LMs) were characterized by investigating infrared spectrum, morphology, particle size, and equilibrium water contents (EWC). A series of tests were employed to evaluate the elasticity of PMs, LMs and Embosphere™, including once compression, twice compression, and stress relaxation test. The pressures of PMs and LMs passing through a catheter were measured on line by our new designed device. Drug release was studied with T-cell apparatus. The properties of PMs and LMs were proved to be suitable for embolization. Both PMs and LMs in this study might be potential embolic agents in the future.

  16. Surface photografting of acrylic acid on poly(dimethylsiloxane). Experimental and dissipative particle dynamics studies.

    Science.gov (United States)

    Ramírez-Gutiérrez, David; Nieto-Draghi, Carlos; Pannacci, Nicolas; Castro, Laura V; Álvarez-Ramírez, Fernando; Creton, Benoit

    2015-02-03

    This work includes both experimental and theoretical studies of the wetting property changes of water on a surface of poly(dimethylsiloxane) (PDMS) modified with different amounts of acrylic acid (AA). The default surface properties of PDMS were changed from hydrophobic to hydrophilic behavior which was characterized with contact angle measurements by two approaches: (i) experimental tests of samples subjected to a photografting polymerization procedure to obtain a functionalized surface and (ii) DPD (dissipative particle dynamics) simulations which also involve the calculation of sets of repulsive parameters determined following two methods: the use of the "Blends" module in the Materials Studio software and the calculation of cohesive energy density with molecular simulations. Changes of contact angle values observed from both experimental and numerical simulation results provide qualitative and quantitative information on the wetting behavior of photografted surfaces.

  17. Hydrophobically modified polyelectrolytes I. Dilute solution properties of fluorocarbon-containingpoly(acrylic acid)

    Institute of Scientific and Technical Information of China (English)

    ZHOU, Hui(周晖); SONG, Guo-Qiang(宋国强); ZHANG, Yun-Xiang(章云祥); DIEING, Reinhold; MA, Lian; HAEUSSLING, Lukas

    2000-01-01

    Dilute solution viscosity of fluorocarbon-containing hydrophobically modified poly(acrylic acid) was measured in aqueous solutions of various NaCl concentrations. The intrinsic viscosity ([η]) and Huggins coefficient (kH) were evaluated using Huggins equations. It is found that, at low NaCl concentration, the modified polymers exhibit values of intrinsic viscosity ( [η] ) and Huggins coefficient (kH) similar to those of unmodified polymers. For both of the modified and unmodified polymers, the intrinsic viscosity decreases with increase of NaCl concentration, while the Huggins coefficient increases upon addition of NaCl. But the variation of [η] and kH is more significant for the modified polymers, which reflects the enhanced intra- and intermolecular hydrophobic association at higher NaCl concentration.

  18. Poly(acrylic acid surface grafted polypropylene films: Near surface and bulk mechanical response

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available Radical photo-grafting polymerization constitutes a promising technique for introducing functional groups onto surfaces of polypropylene films. According to their final use, surface grafting should be done without affecting overall mechanical properties. In this work the tensile drawing, fracture and biaxial impact response of biaxially oriented polypropylene commercial films grafted with poly(acrylic acid (PAA were investigated in terms of film orientation and surface modification. The variations of surface roughness, elastic modulus, hardness and resistance to permanent deformation induced by the chemical treatment were assessed by depth sensing indentation. As a consequence of chemical modification the optical, transport and wettability properties of the films were successfully varied. The introduced chains generated a PAA-grafted layer, which is stiffer and harder than the neat polypropylene surface. Regardless of the surface changes, it was proven that this kind of grafting procedure does not detriment bulk mechanical properties of the PP film.

  19. Poly(acrylic acid)-stabilized colloidal gold nanoparticles: synthesis and properties.

    Science.gov (United States)

    Jans, Hilde; Jans, Karolien; Lagae, Liesbet; Borghs, Gustaaf; Maes, Guido; Huo, Qun

    2010-11-12

    Combining the intriguing optical properties of gold nanoparticles with the inherent physical and dynamic properties of polymers can give rise to interesting hybrid nanomaterials. In this study, we report the synthesis of poly(acrylic acid) (PAA)-capped gold nanoparticles. The polyelectrolyte-wrapped gold nanoparticles were fully characterized and studied via a combination of techniques, i.e. UV-vis and infrared spectroscopy, dark field optical microscopy, SEM imaging, dynamic light scattering and zeta potential measurements. Although PAA-capped nanoparticles have been previously reported, this study revealed some interesting aspects of the colloidal stability and morphological change of the polymer coating on the nanoparticle surface in an electrolytic environment, at various pH values and at different temperatures.

  20. Poly (acrylic acid)-capped lanthanide-doped BaFCl nanocrystals: synthesis and optical properties.

    Science.gov (United States)

    Ju, Qiang; Luo, Wenqin; Liu, Yongsheng; Zhu, Haomiao; Li, Renfu; Chen, Xueyuan

    2010-07-01

    Water-soluble lanthanide-doped BaFCl nanophosphors with the surface functionalized by a layer of poly (acrylic acid) are synthesized via a facile one-step solvothermal method. Intense long-lived luminescence is realized from visible to near-infrared (NIR) by doping with different lanthanide ions. The emission and excitation spectra of Eu(3+) indicate that the doped lanthanide ions occupy a site close to the surface of the nanoparticles. Strong NIR emissions of Nd(3+) and green luminescence of Tb(3+) using Ce(3+) as sensitizers are also achieved in BaFCl nanoparticles. The synthesized nanoparticles featuring long-lived luminescence in either visible or NIR regions may have potential applications as luminescent labels for biological applications.

  1. Cascade enzymatic catalysis in poly(acrylic acid) brushes-nanospherical silica for glucose detection.

    Science.gov (United States)

    Zhao, Yan; Wang, Ying; Zhang, Xiaobin; Kong, Rongmei; Xia, Lian; Qu, Fengli

    2016-08-01

    The ultrasensitive monitoring of glucose with a fast and accurate method is significant in potential therapeutics and optimizes protein biosynthesis. Incorporation of enzyme into matrix is considered as promising candidates for constructing highly sensitive glucose-responsive systems. In this study, three-dimensional poly(acrylic acid) brushes-nanospherical silica (PAA-nano silica) with high amplification capability and stability were used to covalently immobilize bienzymes for cascade enzymatic catalysis. The major advantages of PAA-nano silica-bienzyme co-incorporation is that the enzymes are proximity distribution, and such close confinement both minimized the diffusion of intermediates among the enzymes in the consecutive reaction and improve the utilization efficiency of enzymes, thereby enhancing the overall reaction efficiency and specificity. Thus, this present bienzymatic biosensor shows robust signal amplification and ultrasensitivity of glucose-responsive properties with a detection limit of 0.04μM.

  2. 77 FR 20314 - 2-Propenoic Acid, 2-Methyl-, 2-Ethylhexyl Ester, Telomer With 1-Dodecanethiol, Ethenylbenzene and...

    Science.gov (United States)

    2012-04-04

    ... AGENCY 40 CFR Part 180 2-Propenoic Acid, 2-Methyl-, 2-Ethylhexyl Ester, Telomer With 1- Dodecanethiol...-methyl-, 2- ethylhexyl ester, telomer with 1-dodecanethiol, ethenylbenzene and 2- methyloxirane polymer...-Propenoic acid, 2-methyl-, 2-ethylhexyl ester, telomer with 1-dodecanethiol, ethenylbenzene and...

  3. 40 CFR 721.10074 - Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester.

    Science.gov (United States)

    2010-07-01

    ...-dimethylcyclohexyl)ethyl ester. 721.10074 Section 721.10074 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10074 Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester. (a... acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester (PMN P-05-568; CAS No. 477218-59-0)...

  4. 40 CFR 721.4097 - 7-Oxabicyclo[4.1.0]heptane-3-carboxylic acid, methyl ester.

    Science.gov (United States)

    2010-07-01

    ..., methyl ester. 721.4097 Section 721.4097 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4097 7-Oxabicyclo heptane-3-carboxylic acid, methyl ester. (a) Chemical...-oxabicyclo heptane-3-carboxylic acid, methyl ester (PMN P-98-101) is subject to reporting under this...

  5. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Science.gov (United States)

    2010-07-01

    ...-oxopropenyloxy)ethyl) ester . 721.1950 Section 721.1950 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  6. 78 FR 5761 - Proposed Modification of Significant New Uses of Ethaneperoxoic Acid, 1,1-Dimethylpropyl Ester

    Science.gov (United States)

    2013-01-28

    ..., 1,1-Dimethylpropyl Ester AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule... rule (SNUR) for the chemical substance identified as ethaneperoxoic acid, 1,1-dimethylpropyl ester..., process, or use the chemical substance identified as ethaneperoxoic acid, 1,1-dimethylpropyl ester (PMN...

  7. Synthesis of Hydrophobically Modified Poly(acrylic acid) Gels and Interaction of the Gels with Cationic/Anionic Surfactants

    Institute of Scientific and Technical Information of China (English)

    TIAN,Qin(田琴); TANG,Xiao-Zhen(唐小真); ZHUANG,Dong-Qing(庄东青); ZHANG,Yun-Xiang(章云祥)

    2002-01-01

    Poly( acrylic acid) (PAA) gel network with only chemical crosslinking and hydrophobically modified PAA (HM-PAA)gels with both chemical and physical crosslinking were synthesized by radical polymerization in tert-butanol, using ethylene glycol dimethacrylate (EGDMA) as crosslinker, and 2-(Nethylperfiuorooctanesulfoamido) ethyl methacrylate ( FMA ),stearyl acrylate (SA) or lauryl acrylate (LA) as hydrophobic comonomer respectively. The effect of the fractions and the species of the hydrophobes on swelling properties of HM-PAA gels and the interaction of gels and surfactants were studied.The results showed that the swelling ratio of HM-PAA gels exhibited a sharp decrease with increasing hydrophobic comonomer concentration, which could be ascribed to the formation of strong hydrophobic association among hydrophobic groups. It was proved that two kinds of binding mechanisms of surfactant/gel and different kinds of hydrophobic dusters existed in gels containing both physical and chemical networks.

  8. Fluorescence and Judd-Ofelt analysis of rare earth complexes with maleic anhydride and acrylic acid

    Institute of Scientific and Technical Information of China (English)

    WEN Shipeng; ZHANG Xiaoping; HU Shui; ZHANG Liqun; LIU Li

    2008-01-01

    Two kinds of Eu-complexes, Eu(TTA)2(Phen)(AA) and Eu(TTA)2(Phen)(MA) (HTFA=2-Thenoyltrifluoroacetone, Phen=1,10-phenanthroline, AA=acrylic acid, MA=Maleic anhydride), which combined the excellent fluorescence properties of Eu(TTA)2(Phen)(H2O) and the reactivity of acrylic acid and maleic anhydride with radicals, were synthesized. The two complexes were characterized by elemental analysis, infrared (IR) spectra, and X-ray photoelectron spectroscopy (XPS). Based on the data shown from the fluorescent spectra of the Eu-MA and Eu-AA complexes, the Ωλ (λ=2 and 4) experimental intensity parameters were calculated. The results demonstrated that the Ω2 intensity parameters for the two complexes were smaller than those for the Eu(TTA)2(Phen)(H2O) complex, indicating that a less symmetri-cal chemical environment existed in the complexes. It implied that the radiative efficiency of the 5D0 of these two complexes could be en-hanced by ligand of MA and AA, respectively. The luminescent lifetime of the Eu-AA (τ=7.26×10-4 s) or Eu-MA complex (τ=-8.12×10-4 s) was higher than that of the Eu(TTA)2(Phen)(H2O) complex, which was attributed to the substitution of the water molecule (H2O) in Eu(TTA)2(Phen)(H2O) by the MA or AA ligand.

  9. Preparation of porous chitosan-poly(acrylic acid)-calcium phosphate hybrid nanoparticles via mineralization

    Institute of Scientific and Technical Information of China (English)

    CHEN ChangJing; DENG Yu; YAN ErYun; HU Yong; JIANG XiQun

    2009-01-01

    In this work,the preparation of chitosan-poly(acrylic acid)-calcium phosphate hybrid nanoparticles (CS-PAA-CaP NP) based on the mineralization of calcium phosphate (CAP) on the surface of chitosan-poly (acrylic acid) nanoparticles (CS-PAA NPs) was reported. CS-PAA-CaP NPs were achieved by directly adding ammonia to the aqueous solution of CS-PAA nanoparticles or by thermal decomposition of urea in the aqueous solution of CS-PAA nanoparticles,resulting in the mineralization of CaP on the surface of CS-PAA NPs. Through these two routes,especially using urea as a pH-regulator,the precipitation of CS-PAA NPs,a common occurrence in basic environment,was avoided. The size,morphology and ingredient of CS-PAA-CaP hybrid nanoparticles were characterized by dynamic light scattering (DLS),transmission electron microscope (TEM),scanning electron microscope (SEM),thermogravimetry analysis (TGA) and X-ray diffractometer (XRD). When urea was used as the pH regulator to facilitate the mineralization during the thermal urea decomposition procedure,regular CS-PAA-CaP hybrid nanoparticles with a porosity-structural CaP shells and 400-600 nm size were obtained. TGA result revealed that the hybrid NPs contained approximately 23% inorganic component,which was consistent with the ratio of starting materials. The XRD spectra of hybrid nanoparticles indicated that dicalcium phosphate (DCP:CaHPO4) crystal was a dominant component of mineralization.The porous structure of the CS-PAA-CaP hybrid NPs might be greatly useful in pharmaceutical and other medical applications.

  10. Ultrasound-assisted synthesis of aliphatic acid esters at room temperature.

    Science.gov (United States)

    Hobuss, Cristiane B; Venzke, Dalila; Pacheco, Bruna S; Souza, Alexander O; Santos, Marco A Z; Moura, Sidnei; Quina, Frank H; Fiametti, Karina G; Vladimir Oliveira, J; Pereira, Claudio M P

    2012-05-01

    This work describes the ultrasound-assisted synthesis of saturated aliphatic esters from synthetic aliphatic acids and either methanol or ethanol. The products were isolated in good yields after short reaction times under mild conditions.

  11. Enhancement of Emulsifying Properties of Cuttlefish Skin Gelatin by Modification with N-hydroxysuccinimide Esters of Fatty Acids

    NARCIS (Netherlands)

    Aewsiri, T.; Benjakul, S.; Visessanguan, W.; Encarnacion, A.B.; Wierenga, P.A.; Gruppen, H.

    2013-01-01

    Cuttlefish (Sepia pharaonis) skin gelatin modified with N-hydroxysuccinimide esters of various fatty acids including capric acid (C10:0), lauric acid (C12:0), and myristic acid (C14:0) at different molar ratios was characterized and determined for emulsifying property. Fatty acid esters were incorpo

  12. Isolation and characterization of esters of indole-3-acetic acid from the liquid endosperm of the horse chestnut (Aesculus species)

    Science.gov (United States)

    Domagalski, W.; Schulze, A.; Bandurski, R. S.

    1987-01-01

    Esters of indole-3-acetic acid were extracted and purified from the liquid endosperm of immature fruits of various species of the horse chestnut (Aesculus parviflora, A. baumanni, A. pavia rubra, and A. pavia humulis). The liquid endosperm contained, at least 12 chromatographically distinct esters. One of these compounds was purified and characterized as an ester of indole-3-acetic acid and myo-inositol. A second compound was found to be an ester of indole-3-acetic acid and the disaccharide rutinose (glucosyl-rhamnose). A third compound was partially characterized as an ester of indole-3-acetic acid and a desoxyaminohexose.

  13. Long-chain alkanoic acid esters of lupeol from Dorstenia harmsiana Engl. (Moraceae).

    Science.gov (United States)

    Poumale, Herve Martial P; Awoussong, Kenzo Patrice; Randrianasolo, Rivoarison; Simo, Christophe Colombe F; Ngadjui, Bonaventure Tchaleu; Shiono, Yoshihito

    2012-01-01

    In addition to lupeol (1a), three long-chain alkanoic acid esters of lupeol, in which two were new, were isolated from the hexane and ethyl acetate twigs extract of Dorstenia harmsiana Engl. (Moraceae). The structures of the new compounds were elucidated on the basis of 1D and 2D NMR experiments. Some isolated compounds were evaluated for their antimicrobial activities. The lupeol and its three long-chain alkanoic acid esters showed antifungal and antibacterial activities.

  14. High Performance Fatty Acid-Based Vinyl Ester Resin for Liquid Molding

    Science.gov (United States)

    2007-07-01

    novolac epoxy, and Epon 828, a diglycidyl ether of bisphenol A ( DGEBA ), were purchased from Hexion Specialty Chemicals and was used to synthesize vinyl... DGEBA vinyl ester resins with n~0.1 and containing no styrene, CN 151 and RDX 26936, were obtained from Sartomer and Cytec Surface Specialties Inc...Diglycidyl ether of bisphenol-A ( DGEBA ) Methacrylic Acid Figure 1: The reaction of DGEBA and methacrylic acid to produce the vinyl ester 2.3

  15. Synthesis and characterization of new biodegradable thermosensitive polyphosphazenes with lactic acid ester and methoxyethoxyethoxy side groups

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Two novel biodegradable thermosensitive polyphosphazenes with lactic acid ester and methoxyethoxyethoxy side groups were synthesized via the macromolecular substitution reactions of poly(dichlorophosphazene) with the sodium salt of lactic acid ester and sodium methoxyethoxyethoxide.Their structures were confirmed by ~(31)p NMR,~1H NMR,~(13)C NMR,IR,DSC,and elemental analysis.The lower critical solution temperature(LCST) behavior in water and in vitro degradation property of the polymers was investigated....

  16. Research on the Sizing Performance of Starch Grafted Poly-hydroxy Alkyl-acid Esters

    Institute of Scientific and Technical Information of China (English)

    GUO La-mei; GUO Liang-hong

    2010-01-01

    Starch grafted poly-hydroxy alkyl-acid esters were prepared via graft polymerization. Different characteristics of grafted starches were tested such as viscosity, viscosity stability, adhesion as well as properties of sized yams. Sizing performance was analyzed from the aspect of physical and chemical reactions between polymer molecules. It shows that starch grafted poly-hydroxy alkyl-acid esters have excellent sizing performance and could absolutely be used as sizes for polyester-cotton yarns.

  17. Synthesis, characterization and swelling behavior investigation of gela-tin-g-poly(acrylic acid-co-itaconic acid

    Directory of Open Access Journals (Sweden)

    Hossein Hosseinzadeh

    2014-07-01

    Full Text Available A novel pH-responsive superabsorbent hydrogel based on gelatin was prepared through crosslinking copolymerization of poly (acrylic acid and poly (itaconic acid. The copolymerization conditions including monomers, initiator, gelatin and crosslinker concentration, reaction temperature, and neutralization percent were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The hydrogels structure was confirmed using Fourier-transform infrared, thermogravimetric analysis, differential scanning calorimetric and scanning electron microscopy. The swelling of the superabsorbing hydrogel was examined in buffer solutions with pH ranged 3-12. Moreover, the swelling of the hydrogel was conducted in 0.15 M aqueous solutions of NaCl, CaCl2, and AlCl3. Due to the high swelling capacity in salt solutions, the hydrogel may be referred to as "low-salt sensitive" superabsorbent.

  18. Spectroscopic and quantum chemical analysis of Isonicotinic acid methyl ester

    Science.gov (United States)

    Shoba, D.; Periandy, S.; Govindarajan, M.; Gayathri, P.

    2015-02-01

    In this present study, an organic compound Isonicotinic acid methyl ester (INAME) was structurally characterized by FTIR, FT-Raman, and NMR and UV spectroscopy. The optimized geometrical parameters and energies of all different and possible conformers of INAME are obtained from Density Functional Theory (DFT) by B3LYP/6-311++G(d,p) method. There are three conformers (SI, SII-1, and SII-2) for this molecule (ground state). The most stable conformer of INAME is SI conformer. The molecular geometry and vibrational frequencies of INAME in the ground state have been calculated by using HF and density functional method (B3LYP) 6-311++G (d,p) basis set. Detailed vibrational spectral analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The computed vibrational frequencies were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. A study on the electronic properties, such as HOMO and LUMO energies were performed by time independent DFT approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (μ) and first hyper polarizability (β) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results show that the INAME molecule may have microscopic nonlinear optical (NLO) behavior with non zero values. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by gauge independent atomic orbital (GIAO) method.

  19. Pemisahan dan Pemurnian Phthalic Acid Ester dari Minyak Nyamplung

    Directory of Open Access Journals (Sweden)

    William Ekaputra Taifan

    2013-09-01

    Full Text Available Minyak nyamplung dikenal sebagai minyak yang tidak dapat dikonsumsi. Oleh sebab itu, penelitian tentang minyak ini hanya fokus pada konversi minyak menjadi biodiesel. Pada penelitian ini, kami berusaha untuk memisahkan resin beracun dari fraksi metanol menggunakan ekstraksi pelarut diikuti kolom kromatografi. Resin beracun ini diidentifikasi sebagai phthalic acid ester (PAE. PAE ini biasanya digunakan sebagai zat aditif di industri polimer. Minyak nyamplung mengandung 1,8% PAE, yang masih jauh melebihi nilai ambang batas. Isolasi PAE dari minyak ini diharapkan dapt mengubah minyak yang tidak dapat dikonsumsi menjadi suplemen makanan yang bernilai. Proses isolasi PAE dimulai dengan memisahkan senyawa yang diinginkan dari lipid menggunakan ekstraksi pelarut bertingkat dengan metanol dan n-heksan. Analisa mass spectra dari fraksi pertama dan fraksi kedua metanol menunjukkan kandungan PAE sebesar 60% dan 6% pada tiap fraksi. Fraksi heksan tidak mengandung PAE. PAE yang terkandung pada fraksi metanol diisolasi lebih lanjut dari asam lemak menggunakan liquid column chromatography dengan n-heksan – etil asetat sebagai mobile phase. Bis- 2ethylhexyl phthalate diidentifikasi pada ketiga fraksi sesuai dengan hasil analisa GC-MS. Fraksi pertama diambil pada kondisi mobile phase 5% etil asetat, sedangkan fraksi kedua merupakan campuran 5% etil asetat dan 10% etil asetat. Fraksi ketiga diambil pada kondisi mobile phase 10% etil asetat mengandung PAE sebesar 98%. Fraksi keempat merupakan campuran 10% dan 15% mobile phase dan mengandung PAE sebesar 97%. Akhirnya, kandungan PAE pada fraksi metanol sebesar 58%. Dari hasil analisa, dapat disimpulkan bahwa mobile phase yang optimum untuk kromatografi adalah 10- 15% etil asetat dalam n-heksan.

  20. Controlled release of insulin through hydrogels of (acrylic acid)/trimethylolpropane triacrylate

    Science.gov (United States)

    Raymundi, Vanessa C.; Aguiar, Leandro G.; Souza, Esmar F.; Sato, Ana C.; Giudici, Reinaldo

    2016-10-01

    Hydrogels of poly(acrylic acid) crosslinked with trimethylolpropane triacrylate (TMPTA) were produced through solution polymerization. After these hydrogels were loaded with insulin solution, they evidenced swelling. Experiments of controlled release of insulin through the hydrogels were performed in acidic and basic media in order to evaluate the rates of release of this protein provided by the referred copolymer. Additionally, a mathematical description of the system based on differential mass balance was made and simulated in MATLAB. The model consists of a system of differential equations which was solved numerically. As expected, the values of swelling index at the equilibrium and the rates of insulin release were inversely proportional to the degree of crosslinking. The mathematical model provided reliable predictions of release profiles with fitted values of diffusivity of insulin through the hydrogels in the range of 6.0 × 10-7-1.3 × 10-6 cm2/s. The fitted and experimental values of partition coefficients of insulin between the hydrogel and the medium were lower for basic media, pointing out good affinity of insulin for these media in comparison to the acidic solutions.

  1. Stereocontrolled Synthesis of (E)-β, γ-Unsaturated Esters via Palladium-Catalyzed Cross-Coupling of (E)-Alkenylboronic Acids with a-Bromoacetic Esters

    Institute of Scientific and Technical Information of China (English)

    DUAN Yazhen; ZHANG Jianshe; YANG Jun; DENG Minzhi

    2009-01-01

    The cross-coupling reaction of trans-alkenylboronic acids with α-bromoacetic esters was firstly studied. It was found that using Pd(OAc)2 as catalyst, a bulky electron-rich phospine, (2-dicyclohexylphospino-biphenyl) as ligand, the reaction can be readily accomplished to give specific (E)-β,γ-unsaturated esters in high yields.

  2. Thermophysical properties of starch and whey protein composite prepared in presence of organic acid and esters

    Science.gov (United States)

    Previously, we prepared starch and protein composite by reactive mixing in presence of various organic acids and found that use of these acid esters resulted in composites with good mechanical properties. In this study, concentration (% w/w) of acid citrates in the starch-protein composites were var...

  3. Selective synthesis of thiodiglycol dicarboxylic acid esters via -TsOH/C-catalysed direct esterification

    Indian Academy of Sciences (India)

    Dahong Jiang; Min Huang

    2012-09-01

    The esterification of thiodiglycol and long alkyl-chain carboxylic acids is reported. Reaction of thiodiglycol with carboxylic acid via -TsOH/C-catalysed direct esterification afforded thiodiglycol dicarboxylic acid esters in good yields and chemoselectivity. The use of immobilized -TsOH on activated carbon as catalyst is crucial for the transformation.

  4. Fabrication and Characterization of Gd-DTPA-Loaded Chitosan-Poly(Acrylic Acid) Nanoparticles for Magnetic Resonance Imaging.

    Science.gov (United States)

    Ahmed, Arsalan; Zhang, Chao; Guo, Jian; Hu, Yong; Jiang, Xiqun

    2015-08-01

    Gd-DTPA-loaded chitosan-poly(acrylic acid) nanoparticles (Gd-DTPA@CS-PAA NPs) were formulated based on the reaction system of water-soluble polymer-monomer pairs of acrylic acid in chitosan solution followed by sorption of Gd-DTPA. Morphological investigations revealed the spherical shape of these NPs with about 220 nm particle size. These NPs showed charge reversal characteristic in acidic solution. In vitro and in vivo magnetic characteristics of these NPs were explored to estimate their utilization in targeted enhanced magnetic resonance imaging. Relaxation studies showed that these NPs possessed pH susceptible relaxation properties, which could introduce in vivo-specific distribution of contrast agent. MRI experiment showed that these nanoparticles had better results in contrast enhancement, and the concentration of contrast agent increased in liver and brain with increment in time. Thus, these NPs could maintain in vivo long circulation and high relaxation rate and were suitable agents for magnetic resonance imaging.

  5. In vitro skin permeation and retention of 5-aminolevulinic acid ester derivatives for photodynamic therapy.

    Science.gov (United States)

    De Rosa, Fernanda Scarmato; Tedesco, Antônio Cláudio; Lopez, Renata Fonseca Vianna; Pierre, Maria Bernadete Riemma; Lange, Norbert; Marchetti, Juliana Maldonado; Rotta, Jeane Cristina Gomes; Bentley, Maria Vitória Lopes Badra

    2003-04-29

    In photodynamic therapy (PDT), 5-aminiolevulinic acid (5-ALA) applied topically is converted, via the heme cycle, into protoporphyrin IX (PpIX), a photosensitizing agent, which upon excitation with light can induce tumor destruction. Due to its hydrophilic and zwitterionic characteristics, 5-ALA has limited penetration into the skin. More lipophilic 5-ALA ester derivatives are expected to cross stratum corneum more easily than 5-ALA. According to the determination of the partition coefficients of 5-ALA methyl, n-butyl, n-hexyl and n-octyl esters, these compounds showed an increased affinity to the SC, with 5-ALA hexyl ester and 5-ALA-octyl ester having the highest partition coefficients. Our in vitro skin permeation studies demonstrated an increased permeated amount for hexyl-ALA after 6 h of incubation, compared to other esters and 5-ALA. After 6 h, more 5-ALA-hexyl ester and -octyl ester were retained at viable epidermis and dermis than 5-ALA. According to these results, and considering that the conversion of 5-ALA into PpIX occurs preferentially in epidermis, it can be supposed that topical use of ester derivatives with longer chains (C(6) or C(8)) is an interesting proposal to optimize topical 5-ALA-PDT

  6. A MORPHOLOGICAL STUDY OF POLY(DIVINYLBENZENE-co-ACRYLIC ACID) IN CROSSLINKING PRECIPITATION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Feng Bai; Xin-lin Yang; Wen-qiang Huang

    2006-01-01

    Divinylbenzene-80 (DVB-80) and polar monomer acrylic acid (AA) having hydrogen bonding at a total monomer loading of 5 vol% were precipitated-copolymerized in a variety of organic solvents with 2,2'-azobis(isobutyronitrile) (AIBN) as initiator. The experiments were investigated from a two-dimensional matrix, i.e., the actual crosslinking degree of DVB varying from 0 to 80% and the solvent composition varying from 0 to 100% of toluene mixture with acetonitrile, when the mixture of acetonitrile and toluene was used as the reaction solvent. Under various reaction conditions, six distinct morphologies including soluble polymers, swellable microgels, coagulum, irregular microparticles, and nano-/micrometer microspheres were formed and the structures of these polymer architectures were described. A morphological map was utilized to discuss the effects of both crosslinking degree of DVB and composition of solvent on the transitions between morphology domains. The results demonstrated that the microspheres are formed by an internal contraction due to the marginal solvency of the continuous phase and the crosslinking of the polymer network through the covalent bonding from DVB as well as the interchain hydrogen-bonding between the carboxylic acid units.

  7. Ultra-Thin Films of Poly(acrylic acid/Silver Nanocomposite Coatings for Antimicrobial Applications

    Directory of Open Access Journals (Sweden)

    Alaa Fahmy

    2016-01-01

    Full Text Available In this work not only colloids of poly(acrylic acid (PAA embedded with silver nanoparticles (Ag-NPs but thin films (10 nm also were deposited using electrospray deposition technique (ESD. A mixture of sodium borohydride (NaBH4 and ascorbic acid (AA were utilized to reduce the silver ions to generate Ag-NPs in the PAA matrix. Moreover, sodium tricitrate was used to stabilize the prepared colloids. The obtained colloids and films were characterized using UV-visible, transmission electron microscopy (TEM. UV-Vis results reveal that an absorption peak at 425 nm was observed in presence of PAA-AgNO3-AA-citrate-NaBH4. This peak is attributed to the well-known surface plasmon resonance of the silver bound in Ag-NPs, while the reduction was rendering and/or inhibiting in absence of the AA and citrate. FTIR spectroscopy was used to study the mechanism of the reaction process of silver nitrate with PAA. TEM images showed the well dispersion of Ag-NPs in the PAA matrix with average particle size of 8 nm. The antimicrobial studies showed that the Ag-NPs embedded in the PAA matrix have proven to have a significant antimicrobial activity against E. coli, B. subtilis, and C. albicans.

  8. Shell and core cross-linked poly(L-lysine)/poly(acrylic acid) complex micelles.

    Science.gov (United States)

    Hsieh, Yi-Hsuan; Hsiao, Yung-Tse; Jan, Jeng-Shiung

    2014-12-21

    We report the versatility of polyion complex (PIC) micelles for the preparation of shell and core cross-linked (SCL and CCL) micelles with their surface properties determined by the constituent polymer composition and cross-linking agent. The negatively and positively charged PIC micelles with their molecular structure and properties depending on the mixing weight percentage and polymer molecular weight were first prepared by mixing the negatively and positively charged polyions, poly(acrylic acid) (PAA) and poly(L-lysine) (PLL). The feasibility of preparing SCL micelles was demonstrated by cross-linking the shell of the negatively and positively charged micelles using cystamine and genipin, respectively. The core of the micelles can be cross-linked by silica deposition to stabilize the assemblies. The shell and/or core cross-linked micelles exhibited excellent colloid stability upon changing solution pH. The drug release from the drug-loaded SCL micelles revealed that the controllable permeability of the SCL micelles can be achieved by tuning the cross-linking degree and the SCL micelles exhibited noticeable pH-responsive behavior with accelerated release under acidic conditions. With the versatility of cross-linking strategies, it is possible to prepare a variety of SCL and CCL micelles from PIC micelles.

  9. Synthesis of poly acrylic acid modified silver nanoparticles and their antimicrobial activities

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Zhihui [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Wang, Zhihua [Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004 (China); Sun, Lei, E-mail: sunlei@henu.edu.cn [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Li, Binjie [Key Laboratory of Cellular and Molecular Immunology, Henan University, Kaifeng 475004 (China); Zhao, Yanbao [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China)

    2014-08-01

    Poly acrylic acid modified silver (Ag/PAA) nanoparticles (NPs) have been successfully synthesized in the aqueous solution by using tannic acid as a reductant. The structure, morphology and composition of Ag/PAA NPs were characterized by various techniques such as X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible absorption spectroscopy (UV–vis) and thermogravimetry analysis (TGA). The results show that PAA/Ag NPs have a quasi-ball shape with an average diameter of 10 nm and exhibit well crystalline, and the reaction conditions have some effect on products morphology and size distribution. In addition, the as-synthesized Ag/PAA NPs antimicrobial activities against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) were evaluated by the methods of broth dilution, cup diffusion, optical density (OD600) and electron microscopy observation. The as-synthesized Ag/PAA NPs exhibit excellent antibacterial activity. The antimicrobial mechanism may be attributed to the damaging of bacterial cell membrane and causing leakage of cytoplasm. - Highlights: • Dispersed Ag/PAA NPs with small size were synthesized. • Ag/PAA NPs exhibited excellent antimicrobial properties. • Interaction mechanism between Ag/PAA NPs and bacteria was verified.

  10. Synthesis of esters of androgens with unsaturated fatty acids for androgen requiring therapy.

    Science.gov (United States)

    Aiello, F; Garofalo, A; Aloisi, A M; Lamponi, S; Magnani, A; Petroni, A

    2013-06-01

    Androgens' metabolism and activity are gaining a more and more important role in human physiology particularly referring to aging and to neurodegenerative diseases. Androgen treatment is often required for long-lasting disorders. In order to improve their duration and effects, androgens can be administered as esters of carboxylic acids. The novelty of our research is the use of esters of androgens with specific unsaturated fatty acids, in order to reduce possible side effects particularly related to chronic pathologies with altered lipid homeostasis such as X-linked adrenoleukodystrophy and cardiovascular disorders. Thus the esters of the main androgenic substances testosterone, dihydrotestosterone (DHT) and their metabolite 5α-androstan-3α,17β-diol were chemically obtained by coupling with different unsaturated fatty acids. To this aim, fatty acids with various degree of unsaturation and belonging to different series were selected. Specifically, oleic acid (18:1, n-9), linoleic acid (18:2, n-6), and the n-3 fatty acids, α-linolenic acid (18:3), eicosapentaenoic acid (EPA, 20:5), and docosahexaenoic acid (DHA, 22:6) were used obtaining corresponding esters with acceptable yields and good degree of purity. All the synthesized compounds were tested for their cytotoxic activities in mouse NIH3T3 and human astrocyte cell lines. The esters demonstrated good tolerability and no in vitro cytotoxic effect in both cell cultures. After these promising preliminary results, the esters will be suitable for in vivo studies in order to ascertain their pharmacokinetic characteristics and their biological effects.

  11. Resolution of 4-amino-cyclopentanecarboxylic acid methyl esters using hydrolytic enzymes.

    Science.gov (United States)

    Mahmoudian, M; Baines, B S; Dawson, M J; Lawrence, G C

    1992-11-01

    A number of esterases (EC 3.1.1.1) and lipases (EC 3.1.1.3) of microbial and mammalian origin were screened for the ability to resolve racemic 4-amino-cyclopentanecarboxylic acid methyl ester derivatives as potential intermediates in the production of carbocyclic nucleosides. Surprisingly, functionalization of the remote amino group had a profound effect on both the rate and enantioselectivity of hydrolysis of the methyl ester. 4-(Benzoylamino)-2-cyclopentenecarboxylic acid, methyl ester (V) with pig liver esterase gave the highest enantioselectivity. The residual ester, which was of the correct absolute stereochemistry [(+) 1S, 4R] for carbocyclic nucleoside synthesis, could be obtained in high optical purity. Optimization of pH, solvent type, and concentration improved the enantioselectivity of the process by a further twofold.

  12. A Convenient Route to 4-Carboxy-4-Anilidopiperidine Esters and Acids

    Directory of Open Access Journals (Sweden)

    Gjermund Henriksen

    2012-03-01

    Full Text Available The route selection and development of a convenient synthesis of 4-carboxy-4-anilidopiperidines is described. Previous routes were hampered by the low yield of the target esters as well as the inability to convert the esters to the required free acids. Considerations for large-scale production led to a modified synthesis that utilised a tert-butyl ester of 4-carboxy-4-anilidopiperidines which resulted in a dramatic increase in the overall yield of the target N-propionylated- 4-anilidopiperidine-4-carboxylic acids and their corresponding methyl esters. These compounds are now available for use as precursors and reference standards, of particular value for the production of 11C and 18F-labelled 4-carboxy-4-anilidopiperidine radiotracers.

  13. 40 CFR 721.8500 - 2-Propenoic acid, 2-methyl-, 7-oxabicyclo [4.1.0]hept-3-ylmethyl ester.

    Science.gov (United States)

    2010-07-01

    ...-oxabicyclo hept-3-ylmethyl ester. 721.8500 Section 721.8500 Protection of Environment ENVIRONMENTAL... hept-3-ylmethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance 2-propenoic acid, 2-methyl-, 7-oxabicyclo hept-3-ylmethyl ester (PMN P-89-30) is...

  14. 40 CFR 721.4792 - 2-propenoic acid, 2-methyl-, C11-14-isoalkyl esters, C13-rich.

    Science.gov (United States)

    2010-07-01

    ...-isoalkyl esters, C13-rich. 721.4792 Section 721.4792 Protection of Environment ENVIRONMENTAL PROTECTION... esters, C13-rich. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, C11-14-isoalkyl esters, C13-rich (PMN P-99-1189; CAS...

  15. 40 CFR 721.1578 - 1,4-Benzenedicarboxylic acid, bis[[4-[(ethenyloxy)methyl] cyclohexyl] methyl] ester.

    Science.gov (United States)

    2010-07-01

    ... cyclohexyl] methyl] ester. 721.1578 Section 721.1578 Protection of Environment ENVIRONMENTAL PROTECTION...] methyl] ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,4-benzenedicarboxylic acid, bis cyclohexyl] methyl] ester (PMN P-98-1164; CAS...

  16. 40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

    Science.gov (United States)

    2010-07-01

    ... amino-, di-2-propenyl ester. 721.1725 Section 721.1725 Protection of Environment ENVIRONMENTAL...-, di-2-propenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The..., Benzoic acid, 3,3′-methylenebis [6 amino-, di-2-propenyl ester. (2) The significant new uses are: (i)...

  17. 40 CFR 721.1576 - 1,3-Benzenedicarboxylic acid, bis[[4-[(ethenyloxy)methyl] cyclohexyl] methyl] ester.

    Science.gov (United States)

    2010-07-01

    ... cyclohexyl] methyl] ester. 721.1576 Section 721.1576 Protection of Environment ENVIRONMENTAL PROTECTION...] methyl] ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,3-benzenedicarboxylic acid, bis cyclohexyl] methyl] ester (PMN P-98-1162; CAS...

  18. Myo-inositol esters of indole-3-acetic acid are endogenous components of Zea mays L. shoot tissue

    Science.gov (United States)

    Chisnell, J. R.

    1984-01-01

    Indole-3-acetyl-myo-inositol esters have been demonstrated to be endogenous components of etiolated Zea mays shoots tissue. This was accomplished by comparison of the putative compounds with authentic, synthetic esters. The properties compared were liquid and gas-liquid chromatographic retention times and the 70-ev mass spectral fragmentation pattern of the pentaacetyl derivative. The amount of indole-3-acetyl-myo-inositol esters in the shoots was determined to be 74 nanomoles per kilogram fresh weight as measured by isotope dilution, accounting for 19% of the ester indole-3-acetic acid of the shoot. This work is the first characterization of an ester conjugate of indole-3-acetate acid from vegetative shoot tissue using multiple chromatographic properties and mass spectral identification. The kernel and the seedling shoot both contain indole-3-acetyl-myo-inositol esters, and these esters comprise approximately the same percentage of the total ester content of the kernel and of the shoot.

  19. Orally administered glycidol and its fatty acid esters as well as 3-MCPD fatty acid esters are metabolized to 3-MCPD in the F344 rat.

    Science.gov (United States)

    Onami, Saeko; Cho, Young-Man; Toyoda, Takeshi; Akagi, Jun-ichi; Fujiwara, Satoshi; Ochiai, Ryosuke; Tsujino, Kazushige; Nishikawa, Akiyoshi; Ogawa, Kumiko

    2015-12-01

    IARC has classified glycidol and 3-monochloropropane-1,2-diol (3-MCPD) as group 2A and 2B, respectively. Their esters are generated in foodstuffs during processing and there are concerns that they may be hydrolyzed to the carcinogenic forms in vivo. Thus, we conducted two studies. In the first, we administered glycidol and 3-MCPD and associated esters (glycidol oleate: GO, glycidol linoleate: GL, 3-MCPD dipalmitate: CDP, 3-MCPD monopalmitate: CMP, 3-MCPD dioleate: CDO) to male F344 rats by single oral gavage. After 30 min, 3-MCPD was detected in serum from all groups. Glycidol was detected in serum from the rats given glycidol or GL and CDP and CDO in serum from rats given these compounds. In the second, we examined if metabolism occurs on simple reaction with rat intestinal contents (gastric, duodenal and cecal contents) from male F344 gpt delta rats. Newly produced 3-MCPD was detected in all gut contents incubated with the three 3-MCPD fatty acid esters and in gastric and duodenal contents incubated with glycidol and in duodenal and cecal contents incubated with GO. Although our observation was performed at 1 time point, the results showed that not only 3-MCPD esters but also glycidol and glycidol esters are metabolized into 3-MCPD in the rat.

  20. The influence of poly(acrylic) acid number average molecular weight and concentration in solution on the compressive fracture strength and modulus of a glass-ionomer restorative.

    LENUS (Irish Health Repository)

    Dowling, Adam H

    2011-06-01

    The aim was to investigate the influence of number average molecular weight and concentration of the poly(acrylic) acid (PAA) liquid constituent of a GI restorative on the compressive fracture strength (σ) and modulus (E).

  1. Preparation, characterization, and antibacterial activity studies of silver-loaded poly(styrene-co-acrylic acid) nanocomposites.

    Science.gov (United States)

    Song, Cunfeng; Chang, Ying; Cheng, Ling; Xu, Yiting; Chen, Xiaoling; Zhang, Long; Zhong, Lina; Dai, Lizong

    2014-03-01

    A simple method for preparing a new type of stable antibacterial agent was presented. Monodisperse poly(styrene-co-acrylic acid) (PSA) nanospheres, serving as matrices, were synthesized via soap-free emulsion polymerization. Field-emission scanning electron microscopy micrographs indicated that PSA nanospheres have interesting surface microstructures and well-controlled particle size distributions. Silver-loaded poly(styrene-co-acrylic acid) (PSA/Ag-NPs) nanocomposites were prepared in situ through interfacial reduction of silver nitrate with sodium borohydride, and further characterized by transmission electron microscopy and X-ray diffraction. Their effects on antibacterial activity including inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bactericidal kinetics were evaluated. In the tests, PSA/Ag-NPs nanocomposites showed excellent antibacterial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. These nanocomposites are considered to have potential application in antibacterial coatings on biomedical devices to reduce nosocomial infection rates.

  2. A Novel Approach for the Desalination of Seawater by Means of Reusable Poly(acrylic acid) Hydrogels and Mechanical Force.

    Science.gov (United States)

    Höpfner, Johannes; Klein, Christopher; Wilhelm, Manfred

    2010-08-01

    Desalination of a sodium chloride solution is achieved by the incorporation of salt depleted water into an acrylic acid based hydrogel and the subsequent deswelling of the gel by mechanical force to gain water with a lower salt content. This is a new approach towards the problem of desalination of seawater that has, to the best of our knowledge, not been presented before. In a proof-of-principle experiment the salt content of a 10 g/L NaCl solution could be reduced by 35% in one cycle. The influence of main chemical parameters, e.g. degree of crosslinking, degree of neutralization and experimental parameters like particle size and salt concentration on the desalination process are examined. Possible optimum conditions for the desalination using a poly(acrylic acid) network are discussed and the construction of a simple apparatus for deswelling by mechanical force is described.

  3. Synthesis, characterization, and swelling behaviors of salt-sensitive maize bran-poly(acrylic acid) superabsorbent hydrogel.

    Science.gov (United States)

    Zhang, Mingyue; Cheng, Zhiqiang; Zhao, Tianqi; Liu, Mengzhu; Hu, Meijuan; Li, Junfeng

    2014-09-01

    A novel composite hydrogel was prepared via UV irradiation copolymerization of acrylic acid and maize bran (MB) in the presence of composite initiator (2,2-dimethoxy-2-phenylacetophenone and ammonium persulfate) and cross-linker (N,N'-methylenebis(acrylamide)). Under the optimized conditions, maize bran-poly(acrylic acid) was obtained (2507 g g(-1) in distilled water and 658 g g(-1) in 0.9 wt % NaCl solution). Effects of granularity, salt concentration, and various cations and anions on water absorbency were investigated. It was found that swelling was extremely sensitive to the ionic strength and cation and anion type. Swelling kinetics and water diffusion mechanism in distilled water were also discussed. Moreover, the product showed excellent water retention capability under the condition of high temperature or high pressure. The salt sensitivity, good water absorbency, and excellent water retention capability of the hydrogels give this intelligentized polymer wide potential applications.

  4. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical... acid, mono-C9-11-alkyl esters, sodium salts (PMN P-01-149; CAS No. 84501-49-5) is subject to...

  5. Synthesis and biological evaluation of nigranoic acid esters as novel human neutrophil elastase inhibitors.

    Science.gov (United States)

    Huang, Guoli; Feng, Li; Liu, Bo; He, Yi; Li, Yiming; Chen, Yegao

    2015-01-01

    Human neutrophil elastase (HNE) has been implicated as a major contributor in the pathogenesis of diseases, such as lung disorders and other inflammatory diseases. A series of 12 new nigranoic acid esters were regioselectively synthesised in good yields and evaluated for HNE inhibitory activity. Nigranoic acid exhibited significant inhibitory activity against HNE with the IC50 value of 3.77 μM, and six esters displayed considerable inhibitory effects on HNE with IC50 values in the range of 2.61-8.95 μM. The nigranoic acid esters having phenyls substituted with bromine and trimethoxyls (3h and 3b) showed stronger inhibitory activity on HNE than nigranoic acid.

  6. Identification of 19 phthalic acid esters in dairy products by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Wu, Pinggu; Cai, Chenggang; Yang, Dajin; Wang, Liyuan; Zhou, Yan; Shen, Xianghong; Ma, Bingjie; Tang, Jun

    2015-01-01

    A detection method for 19 kinds of phthalic acid ester compounds analyzed by n-hexane/ether/acetonitrile 1:7:8 v/v/v mixed solvent extraction, quick, easy, cheap, effective, rugged, and safe purification and internal standard method of quantitative gas chromatography with mass spectrometry was established. This method can effectively remove interfering materials, such as lipids, fatty acids, and pigments, from dairy products. The 19 kinds of phthalic acid ester compounds were within a 0.025-0.2 mg/kg range, the recovery rate was 65.2-125.7%, relative standard deviation was 7.9-15.4% (n = 6), and the limit of detection was 0.005-0.02 mg/kg. Concentrations of the 19 kinds of phthalic acid ester compounds ranged between 0.01 and 0.12 mg/kg in ten dairy materials and 20 dairy products. The established method is simple, rapid, accurate, and highly sensitive.

  7. Novel Approach: Tungsten Oxide Nanoparticle as a Catalyst for Malonic Acid Ester Synthesis via Ozonolysis

    Directory of Open Access Journals (Sweden)

    Bilal A. Wasmi

    2014-01-01

    Full Text Available Malonic acid ester was synthesized via the one-step ozonolysis of palm olein. Malonic acid ester was spectroscopically characterized using gas chromatography mass spectroscopy (GC-MS. Tungsten oxide nanoparticles were used as the catalyst, which was characterized via X-ray powder diffraction (XRD and field emission scanning electron microscopy (FE-SEM. Tungsten oxide provided several advantages as a catalyst for the esterification malonic acid such as simple operation for a precise ozonation method, an excellent yield of approximately 10%, short reaction times of 2 h, and reusability due to its recyclability.

  8. Characterization and Antimicrobial Property of Poly(Acrylic Acid) Nanogel Containing Silver Particle Prepared by Electron Beam

    OpenAIRE

    Jong-Bae Choi; Jong-Seok Park; Myung-Seob Khil; Hui-Jeong Gwon; Youn-Mook Lim; Sung-In Jeong; Young-Min Shin; Young-Chang Nho

    2013-01-01

    In this study, we developed a one step process to synthesize nanogel containing silver nanoparticles involving electron beam irradiation. Water-soluble silver nitrate powder is dissolved in the distilled water and then poly(acrylic acid) (PAAc) and hexane are put into this silver nitrate solution. These samples are irradiated by an electron beam to make the PAAc nanogels containing silver nanoparticles (Ag/PAAc nanogels). The nanoparticles were characterized by scanning electron microscopy (S...

  9. Tuning of thermally induced sol-to-gel transitions of moderately concentrated aqueous solutions of doubly thermosensitive hydrophilic diblock copolymers poly(methoxytri(ethylene glycol) acrylate)-b-poly(ethoxydi(ethylene glycol) acrylate-co-acrylic acid).

    Science.gov (United States)

    Jin, Naixiong; Zhang, Hao; Jin, Shi; Dadmun, Mark D; Zhao, Bin

    2012-03-15

    We report in this article a method to tune the sol-to-gel transitions of moderately concentrated aqueous solutions of doubly thermosensitive hydrophilic diblock copolymers that consist of two blocks exhibiting distinct lower critical solution temperatures (LCSTs) in water. A small amount of weak acid groups is statistically incorporated into the lower LCST block so that its LCST can be tuned by varying solution pH. Well-defined diblock copolymers, poly(methoxytri(ethylene glycol) acrylate)-b-poly(ethoxydi(ethylene glycol) acrylate-co-acrylic acid) (PTEGMA-b-P(DEGEA-co-AA)), were prepared by reversible addition-fragmentation chain transfer polymerization and postpolymerization modification. PTEGMA and PDEGEA are thermosensitive water-soluble polymers with LCSTs of 58 and 9 °C, respectively, in water. A 25 wt % aqueous solution of PTEGMA-b-P(DEGEA-co-AA) with a molar ratio of DEGEA to AA units of 100:5.2 at pH = 3.24 underwent multiple phase transitions upon heating, from a clear, free-flowing liquid (sol-to-gel transition temperature (T(sol-gel)) shifted to higher values, while the gel-to-sol transition (T(gel-sol)) and the clouding temperature (T(clouding)) of the sample remained essentially the same. These transitions and the tunability of T(sol-gel) originated from the thermosensitive properties of two blocks of the diblock copolymer and the pH dependence of the LCST of P(DEGEA-co-AA), which were confirmed by dynamic light scattering and differential scanning calorimetry studies. Using the vial inversion test method, we mapped out the C-shaped sol-gel phase diagrams of the diblock copolymer in aqueous buffers in the moderate concentration range at three different pH values (3.24, 5.58, and 5.82, all measured at ~0 °C). While the upper temperature boundaries overlapped, the lower temperature boundary shifted upward and the critical gelation concentration increased with the increase of pH. The AA content in PTEGMA-b-P(DEGEA-co-AA) was found to have a significant

  10. Inhibitory effects of caffeic acid phenethyl ester derivatives on replication of hepatitis C virus.

    Directory of Open Access Journals (Sweden)

    Hui Shen

    Full Text Available Caffeic acid phenethyl ester (CAPE has been reported as a multifunctional compound. In this report, we tested the effect of CAPE and its derivatives on hepatitis C virus (HCV replication in order to develop an effective anti-HCV compound. CAPE and CAPE derivatives exhibited anti-HCV activity against an HCV replicon cell line of genotype 1b with EC50 values in a range from 1.0 to 109.6 µM. Analyses of chemical structure and antiviral activity suggested that the length of the n-alkyl side chain and catechol moiety are responsible for the anti-HCV activity of these compounds. Caffeic acid n-octyl ester exhibited the highest anti-HCV activity among the tested derivatives with an EC50 value of 1.0 µM and an SI value of 63.1 by using the replicon cell line derived from genotype 1b strain Con1. Treatment with caffeic acid n-octyl ester inhibited HCV replication of genotype 2a at a similar level to that of genotype 1b irrespectively of interferon signaling. Caffeic acid n-octyl ester could synergistically enhance the anti-HCV activities of interferon-alpha 2b, daclatasvir, and VX-222, but neither telaprevir nor danoprevir. These results suggest that caffeic acid n-octyl ester is a potential candidate for novel anti-HCV chemotherapy drugs.

  11. Thermolytic reactions of esters. Part IV. The methyl esters of cyanoacetic, acetoacetic and malonic acid

    NARCIS (Netherlands)

    Tonkelaar, W.A.M. den; Louw, R.; Kooyman, E.C.

    1968-01-01

    The compounds on the title proved to be more stable than their ethyl analogues, 1,2-acid elimination being impossible. Acetic acid causes a pronounced rate enhancement. Kinetic as well as product data - including the effect of added water and/or alcohols - are interpreted on the basis of acetic acid

  12. Determination of 4-Chloroindole-3-Acetic Acid Methyl Ester in Lathyrus Vicia and Pisum by Gas Chromatography - Mass Spectrometry

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen; Egsgaard, Helge; Larsen, Elfinn

    1980-01-01

    4-Chloroindole-3-acetic acid methyl ester was identified unequivocally in Lathyrus latifolius L., Vicia faba L. and Pisum sativum L. by thin layer chromatography, gas chromatography and mass spectrometry. The gas chromatographic system was able to separate underivatized chloroindole-3-acetic acid...... methyl ester isomers. The quantitative determination of 4-chloroindole-3-acetic acid methyl ester in immature seeds of these three species was performed by gas chromatography – mass spectrometry using deuterium labelled 4-chloro-indole-3-acetic acid methyl ester as an internal standard. P. sativum...

  13. Synthesis and characterization of acrylamide/acrylic acid hydrogel and its application for crystal violet dye adsorption

    Directory of Open Access Journals (Sweden)

    Chaisuksan, Y.

    2006-03-01

    Full Text Available Acrylamide/acrylic acid (AAm/AAc hydrogel was prepared by free radical polymerization in aqueous solution of acrylamide and acrylic acid as a comonomer using ammonium persulfate and N,N,N’,N’-tetramethylethylenediamine as an initiator system and N,N’-methylenebisacrylamide as a crosslinker at room temperature. The hydrogels were prepared from acrylamide/acrylic acid with the ratios of 2.5/97.5, 5/95, 10/90, 20/80, 30/70, 40/60 and 50/50. The swelling property and the equilibrium water content of the hydrogel were determined in distilled water and in a solution of pH 3, 5, 7 and 8 for 96 hours. The result showed that the maximum swelling and equilibrium water content of the hydrogel obtaining from AAm/ AAc in the ratio of 10/90 were found to be 3,945% and 0.9747 at pH 8, respectively. The adsorption capacity of AAm/AAc (10/90 for crystal violet was also investigated at pH 3, 5, 7, 8 and 9 for 48 hours. It was found that the optimum adsorption capacity of the hydrogel was in the range of 5-8. The adsorption rate was 90% of the sorption completion within 48 hours. The equilibrium data fitted well to the Langmuir isotherm with the maximum adsorption capacity of 116.28 mg/g at pH 7.

  14. Preparation and electro-response of chitosan-g-poly (acrylic acid) hydrogel elastomers with interpenetrating network

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jianli [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi' an, 710062 (China); School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi' an, 710062 (China); Gao, Ling-xiang, E-mail: gaolx@snnu.edu.cn [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi' an, 710062 (China); School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi' an, 710062 (China); Han, Xuewu; Chen, Tao; Luo, Jue; Liu, Kaiqiang; Gao, Ziwei; Zhang, Weiqiang [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi' an, 710062 (China); School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi' an, 710062 (China)

    2016-02-01

    In this article, novel chitosan-g-poly (acrylic acid) hydrogel elastomers were successfully sythesised by grafting chitosan (CTS) onto poly acrylic acid (PAA) through radical polymerization in the presence/absence of direct current electric field. Their structure and electro-response were evaluated through scanning electron microscopy (SEM), infrared spectroscopy (IR), and dynamic mechanical analyser (DMA), respectively. Stress-strain test showed that the toughness of the chitosan-g-PAA elastomer is higher than the PAA gel. The result demonstrates the elastomers obtained in the presence/absence of electric field with similar chemical composition possess different microstructure. The positive electro responsive effect appeared on the elastomers, and both of storage modulus increment and increment sensitivity yielded maximum value at the AA concentration of 14.09 wt% under the applied electric field of 1.5 kV/mm. Thermo gravimetry and differential scanning calorimetry (TG-DSC) showed the elastomers cured under an applied electric field have stronger intramolecular bonding and higher cross-linking density. - Highlights: • The chitosan-g-poly (acrylic acid) hydrogel elastomers have been prepared. • They have ordered structure and positive electro-response under an electric field. • The maximum electro-response occurs near or at the AA wt% of 14.09 under 1.5 kV/mm.

  15. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    Directory of Open Access Journals (Sweden)

    Fangfang LIU

    2015-12-01

    Full Text Available The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA as cross linking agent, and (NH42S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that water absorbency of the resin is 311 g/g, the tap water absorbency is 102 g/g, the normal saline absorbency is 55 g/g, and the artificial urine absorbency is 31 g/g under the optimal synthesis conditions, so the resin has great water absorption rate and water retaining capacity. The FT-IR and SEM analysis shows that the resin with honeycomb network structure is prepared. The successfully synthesized of the resin means that the hemicellulose waste liquid can be highly effectively recycled, and it provides a kind of new raw material for the synthesis of super water absorbent resin.

  16. KINETICS STUDY ON MELT GRAFTING ACRYLIC ACID ONTO LLDPE USING REACTIVE EXTRUSION

    Institute of Scientific and Technical Information of China (English)

    Qiang Shi; Lian-chao Zhu; Chuan-lun Cai; Jing-hua Yin

    2005-01-01

    The kinetics of melt grafting acrylic acid (AA) onto linear low density polyethylene (LLDPE) by using reactive extrusion was investigated. The polymeric peroxides (POOP and POOH) generated by electron beam irradiation were used to initiate the graft reaction. The samples taken out from the barrel at five ports along screw axis were analyzed by FTIR. The spectra show that both the graft copolymerization and homopolymerization proceed in two stages: the graft degree (or mass of homopolymer) increases linearly with the reaction time in the initial stage, and then gradually in the second stage. The rate of graft copolymerization Rg is always faster than that of homopolymerization Rh in the present system and the activation interpreted in terms of solubility and diffusion of monomer, as well as the reactivity and the concentration of reactive species.The relationships between reaction rate and monomer concentration and peroxide concentration were found to be. Rg ∝ [M]1.46[POOP+POOH]0.53 and Rh ∝ [M]1.08[POOH]0.51, which indicate that the addition of monomer to polymeric radicals is a slow step for the graft copolymerization.

  17. Synthesis and characterization of polycaprolactone/acrylic acid (PCL/AA) hydrogel for controlled drug delivery

    Indian Academy of Sciences (India)

    Nazar Mohammad Ranjha; Jahanzeb Mudassir; Sajid Majeed

    2011-12-01

    In the present work biodegradable pH-sensitive polycaprolactone/acrylic acid (PCL/AA) hydrogels have been developed using ethylene glycol dimethacrylate (EGDMA) as a cross-linker and benzoyl peroxide as initiator. For these prepared hydrogels swelling studies, sol–gel fraction analysis and porosity measurements were performed. Results show that swelling of the hydrogels decreases on increasing the concentration of PCL and EGDMA, however swelling of hydrogels increases on increasing the concentration of AA. Results of sol–gel fraction analysis show that gel fraction increases on increasing concentration of monomer AA, polymer PCL as well as cross-linker EGDMA. As far as porosity is concerned, it increases on increasing the concentration of AA and PCL while porosity decreases on increasing the concentration of EGDMA. Hydrogels were characterized by measuring diffusion coefficient () and equilibrium water content (EWC). Network formation, morphology and crystallinity of PCL/AA hydrogels were investigated using FTIR, SEM and XRD, respectively. Tramadol hydrochloride was loaded as model drug and its release pattern was analysed using various kinetic models like zero order, first order, Higuchi and Peppas. Results indicated that most of the samples followed non-Fickian release mechanism.

  18. Optical spectroscopy of Nd{sup 3+} ions in poly(acrylic acid)

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Lara, F [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 Mexico, DF (Mexico); C, A Lira [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 Mexico, DF (Mexico); Ramirez, M O [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Flores, M [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 Mexico, DF (Mexico); Arroyo, R [Departamento de Quimica, Universidad Autonoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 Mexico, DF (Mexico); Caldino, U [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2006-08-30

    Nd{sup 3+} dissolved in solid poly(acrylic acid) was synthesized by polymerization of the monomer partially neutralized with neodymium hydroxide in aqueous solution. The monomer modification and the coordination of ligands to Nd{sup 3+} were confirmed by {sup 1}H NMR spectroscopy. The measured oscillator strengths for transitions from the ground state to the main excited state manifolds compared favourably with calculated electric dipole oscillator strengths. The spontaneous emission rates, the fluorescence branching ratios and the stimulated emission cross sections of the {sup 4}F{sub 3/2} {yields} {sup 4}I{sub 9/2}, {sup 4}F{sub 3/2} {yields} {sup 4}I{sub 11/2} and {sup 4}F{sub 3/2} {yields} {sup 4}I{sub 13/2} transitions, as well as the radiative lifetime and the quantum efficiency of the {sup 4}F{sub 3/2} emitting level, were determined.

  19. Syntheses and Crystal Structures of Two Complexes with 3-(3-Pyridyl)acrylic Acid

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The reaction of 3-(3-pyridyl)acrylic acid (H(3-PYA)) with Co(NO3)2·6H2O or Complex 1 crystallizes in monoclinic, space group C2/c with a = 9.9473(12), b = 13.7227(16), c =14.7376(18) (A), β = 99.043(2)°, V = 1986.7(4) (A)3, Z = 4, Dc = 1.549 g/cm3, μ = 0.921 mm 1, F(000)= 964, R = 0.0786 and wR = 0.1443. Six types of hydrogen bonds and π-π packing interactions molecular architecture. Complex 2 crystallizes in monoclinic, space group P21/n with a =11.3630(16), b = 7.0346(10), c = 12.1365(18) (A), β = 112.545(3)°, V = 896.0(2) (A)3, Z = 2, Dc =1.997 g/cm3,μ = 0.785 mm-1, F(000) = 438, R = 0.0787 and wR = 0.1550. The discrete entity Mn(Ⅱ)(3-PYD)2(H2O)4 is extended into a 3-D supramolecular architecture by four kinds of hydrogen bonds.

  20. Dynamic wettability and contact angles of poly(vinylidene fluoride nanofiber membranes grafted with acrylic acid

    Directory of Open Access Journals (Sweden)

    2010-09-01

    Full Text Available Wettability has been recognized as one of the most important properties of fibrous materials for both fundamental and practical applications. In this study, the plasma induced grafting of acrylic acid (AAc was applied to improve the wettability of the electrospun poly(vinylidene fluoride (PVDF nanofiber membranes. The diameter and chemical structure of the modified PVDF nanofibers were characterized by scanning electron microscopy (SEM and Fourier transform infrared (FTIR. Nitrogen adsorption based on BET (Brunauer, Emmett and Teller principle was employed to measure the specific surface areas and porosities of the modified nanofiber membrances. The contact angles of the modified membrane were evaluated by drop shape analysis (DSA and the modified Washburn method. The dependence of contact angles on specific surface area and porosity was also discussed in this paper. Water adsorptions were used to evaluate the dynamic wetting behavior of the grafted membranes by a dynamic adsorption apparatus (CDCA100-F. The experimental results revealed that the wettablity of the modified PVDF membrane was significantly affected by both surface and porous contact angles.

  1. Isotherm and kinetics study for acrylic acid removal using powdered activated carbon.

    Science.gov (United States)

    Kumar, Arvind; Prasad, B; Mishra, I M

    2010-04-15

    The potential of powdered activated carbon (PAC) for the adsorption of acrylic acid (AA) from aqueous solution was studied at the initial concentration (C(0)) in the range of 50-500 mg/l over the temperature range of 303-348 K. The equilibrium adsorption studies were carried out to evaluate the effect of adsorbent dosage and contact time, change in pH by adding adsorbents and the initial concentration. Langmuir, Freundlich and Redlich-Peterson (R-P) equilibrium isotherm models were tested to represent the data. Error functions were used to test their validity to fit of the adsorption data with the isotherm and kinetic models. The Freundlich isotherm equation is found to best represent the equilibrium separation data in the temperature range of 303-348 K. The maximum adsorption capacity of AA onto PAC was obtained as q(m)=36.23 mg/g with an optimum PAC dosage w=20 g/l at 303 K for C(0)=100 mg/l. The pseudo-second-order kinetics is found to represent the experimental AA-PAC data. The negative value of DeltaG(ad)(o) (-16.60 to -18.18 kJ/mol K) indicate the feasibility and spontaneity of the adsorption process.

  2. Poly(acrylic acid) coating induced 2-line ferrihydrite nanoparticle transport in saturated porous media

    Science.gov (United States)

    Xiang, Aishuang; Yan, Weile; Koel, Bruce E.; Jaffé, Peter R.

    2013-07-01

    Iron oxide and iron nanoparticles (NPs) have been used effectively for environmental remediation, but are limited in their applications by strong retention in groundwater-saturated porous media. For example, delivery of NPs to large groundwater reservoirs would require large numbers of injection wells. To address this problem, we have explored polymer coatings as a surface engineering strategy to enhance transport of oxide nanoparticles in porous media. We report here on our studies of 2-line ferrihydrite NPs and the influence of poly (acrylic acid) (PAA) polymer coatings on the colloidal stability and transport in natural sand-packed column tests simulating flow in groundwater-saturated porous media. Measurements were also made of zeta potential, hydrodynamic diameter, and polymer adsorption and desorption properties. The coated NPs have a diameter range of 30-500 nm. We found that NP transport was improved by PAA coating and that the transport properties could be tuned by adjusting the polymer concentration. Our results demonstrate that a high stability of oxide particles and improved transport can be achieved in groundwater-saturated porous media by introducing negatively charged polyelectrolytes and optimizing polymer concentrations.

  3. Synthesis and Biomedical Applications of Poly((meth)acrylic acid) Brushes.

    Science.gov (United States)

    Qu, Zhenyuan; Xu, Hong; Gu, Hongchen

    2015-07-15

    Poly((meth)acrylic acid) (P(M)AA) brushes possess a number of distinctive properties that are particularly attractive for biomedical applications. This minireview summarizes recent advances in the synthesis and biomedical applications of P(M)AA brushes and brushes containing P(M)AA segments. First, we review different surface-initiated polymerization (SIP) methods, with a focus on recent progress in the surface-initiated controlled/living radical polymerization (SI-CLRP) techniques used to generate P(M)AA brushes with a tailored structure. Next, we discuss biomolecule immobilization methods for P(M)AA brushes, including physical adsorption, covalent binding, and affinity interactions. Finally, typical biomedical applications of P(M)AA brushes are reviewed, and their performance is discussed based on their unique properties. We conclude that P(M)AA brushes are promising biomaterials, and more potential biomedical applications are expected to emerge with the further development of synthetic techniques and increased understanding of their interactions with biological systems.

  4. Preparation and Biophysical Characterization of Poly(amidoamine) Dendrimer-Poly(acrylic acid) Graft.

    Science.gov (United States)

    Dung, Tran Huu; Do, Le Thanh; Loan, Ta Thi; Yoo, Hoon

    2015-01-01

    A series of PAMAM dendrimer generation 5-poly(acrylic acid) grafts were prepared to evaluate the potential use of dendritic grafts as a drug encapsulated nanocarrier. The structural features of the synthesized polymer graft were identified by FT-IR and 1H-NMR spectra and the biophysical properties were characterized by measuring its particle size and zeta potential. The prepared dendrimer G5-PAA grafts had particle size in the range of 600 to 900 nm and the size increased proportionally with the number of PAA on dendrimer surface. The electrostatic property of the dendrimer G5-PAA, carried out by HPLC reversed phase column analysis and the measurement of zeta potential, revealed that both migration time and zeta potential were dependent on the number of grafted PAA. The number of free amino groups on dendrimer G5-PAA, determined quantitatively by fluorescamine assay, was in a reverse order with the reaction mole ratio of dendrimer to PAA. In addition, dendrimer G5-PAA showed a pH-dependent solubility in aqueous solution with characteristic pH region of solubility, depending on the dendrimer generation. The observed biophysical properties indicate that PAMAM dendrimer G5-PAA is promising as a drug encapsulated nanocarrier.

  5. Poly(acrylic acid)-cysteine for oral vitamin B12 delivery.

    Science.gov (United States)

    Sarti, Federica; Iqbal, Javed; Müller, Christiane; Shahnaz, Gul; Rahmat, Deni; Bernkop-Schnürch, Andreas

    2012-01-01

    The aim of this study was to investigate the potential of poly(acrylic acid)-cysteine (PAA-cys) solution and microparticles to enhance the transport of vitamin B12 (VB 12) across Caco-2 cell monolayer and rat intestinal mucosa. Thiolated PAA was synthesized by covalent attachment of L-cysteine. Microparticles were prepared by spray-drying and characterized regarding their size, morphology, thiol group content, VB 12 payload and release, swelling behavior, mucoadhesion, permeation-enhancing effect, and cytotoxicity. Particles with a mean diameter of 2.452±2.26 μm, a payload of 1.11±0.72%, and 190.2±8.85 μmol of free thiol groups per gram were prepared. Swelling behavior studies revealed that the stability of thiolated particles was improved compared with unmodified ones. Of the total VB 12 loaded, 95±0.12% was released within 3 h from thiolated particles. PAA-cys particles exhibited 2.24-fold higher mucoadhesive properties compared with unmodified particles. Permeation experiments with Caco-2 cells proved that permeability of VB 12 with PAA-cys solution and particles was 3.8- and 3.6-fold higher than control, respectively, and with rat intestinal mucosa it was 4.8- and 4.4-fold higher than control, respectively. Negligible cytotoxicity was assessed. PAA-cys is a promising excipient for oral delivery of VB 12 as a solution and as microparticles.

  6. Mechanically stable thermally crosslinked poly(acrylic acid)/reduced graphene oxide aerogels.

    Science.gov (United States)

    Ha, Heonjoo; Shanmuganathan, Kadhiravan; Ellison, Christopher J

    2015-03-25

    Graphene oxide (GO) aerogels, high porosity (>99%) low density (∼3-10 mg cm(-3)) porous materials with GO pore walls, are particularly attractive due to their lightweight, high surface area, and potential use in environmental remediation, superhydrophobic and superoleophilic materials, energy storage, etc. However, pure GO aerogels are generally weak and delicate which complicates their handling and potentially limits their commercial implementation. The focus of this work was to synthesize highly elastic, mechanically stable aerogels that are robust and easy to handle without substantially sacrificing their high porosity or low density. To overcome this challenge, a small amount of readily available and thermally cross-linkable poly(acrylic acid) (PAA) was intermixed with GO to enhance the mechanical integrity of the aerogel without disrupting other desirable characteristic properties. This method is a simple straightforward procedure that does not include multistep or complicated chemical reactions, and it produces aerogels with mass densities of about 4-6 mg cm(-3) and >99.6% porosity that can reversibly support up to 10,000 times their weight with full recovery of their original volume. Finally, pressure sensing capabilities were demonstrated and their oil absorption capacities were measured to be around 120 g oil per g aerogel(-1) which highlights their potential use in practical applications.

  7. Poly(acrylic acid) coating induced 2-line ferrihydrite nanoparticle transport in saturated porous media

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Aishuang [Princeton University, Chemical and Biological Engineering Department (United States); Yan, Weile [Texas Tech University, Civil and Environmental Engineering (United States); Koel, Bruce E., E-mail: bkoel@princeton.edu [Princeton University, Chemical and Biological Engineering Department (United States); Jaffe, Peter R., E-mail: jaffe@princeton.edu [Princeton University, Civil and Environmental Engineering Department (United States)

    2013-07-15

    Iron oxide and iron nanoparticles (NPs) have been used effectively for environmental remediation, but are limited in their applications by strong retention in groundwater-saturated porous media. For example, delivery of NPs to large groundwater reservoirs would require large numbers of injection wells. To address this problem, we have explored polymer coatings as a surface engineering strategy to enhance transport of oxide nanoparticles in porous media. We report here on our studies of 2-line ferrihydrite NPs and the influence of poly (acrylic acid) (PAA) polymer coatings on the colloidal stability and transport in natural sand-packed column tests simulating flow in groundwater-saturated porous media. Measurements were also made of zeta potential, hydrodynamic diameter, and polymer adsorption and desorption properties. The coated NPs have a diameter range of 30-500 nm. We found that NP transport was improved by PAA coating and that the transport properties could be tuned by adjusting the polymer concentration. Our results demonstrate that a high stability of oxide particles and improved transport can be achieved in groundwater-saturated porous media by introducing negatively charged polyelectrolytes and optimizing polymer concentrations.

  8. A novel poly(acrylic acid-co-acrylamide)/diatomite composite flocculant with outstanding flocculation performance.

    Science.gov (United States)

    Xu, Kun; Liu, Yao; Wang, Yang; Tan, Ying; Liang, Xuecheng; Lu, Cuige; Wang, Haiwei; Liu, Xiusheng; Wang, Pixin

    2015-01-01

    Series of anionic flocculants with outstanding flocculation performance, poly(acrylic acid-co-acrylamide)/diatomite composite flocculants (PAAD) were successfully prepared through aqueous solution copolymerization and applied to flocculate from oil-field fracturing waste-water. The structure of PAAD was characterized by Fourier transform infra-red spectroscopy, (13)C nuclear magnetic resonance and X-ray diffraction tests, and its properties were systematically evaluated by viscometer, thermogravimetry analysis and flocculation measurements. Furthermore, the influences of various reaction parameters on the apparent viscosity of flocculant solution were studied, and the optimum synthesis condition was determined. The novel composite flocculants exhibited outstanding flocculation properties. Specifically, the dosage of composite flocculants that could make the transmittance of treated wastewater exceed 90% was only approximately 12-35 ppm, which was far lower than that of conventional flocculants. Meanwhile, the settling time was lower than 5 s, which was similar to that of conventional flocculants. This was because PAAD flocculants had a higher absorption capacity, and larger chain extending space than conventional linear flocculants, which could refrain from the entanglement of linear polymer chains and significantly improve flocculation capacity.

  9. Low-temperature phase behavior of fatty acid methyl esters by differential scanning calorimetry (DSC)

    Science.gov (United States)

    Fatty acid methyl ester (FAME) mixtures have many uses including biodiesel, lubricants, metal-working fluids, surfactants, polymers, coatings, green solvents and phase-change materials. The physical properties of a FAME mixture depends on the fatty acid concentration (FAC) profile. Some products hav...

  10. Coriander Seed Oil Methyl Esters as Biodiesel Fuel: Unique Fatty Acid Composition and Excellent Oxidative Stability

    Science.gov (United States)

    Coriander (Coriandrum sativum L.) seed oil methyl esters were prepared and evaluated as an alternative biodiesel fuel and contained an unusual fatty acid (FA) hitherto unreported as the principle component in biodiesel fuels: petroselinic (6Z-octadecenoic; 68.5 wt %) acid. Most of the remaining FA...

  11. A study on the effect of the concentration of N,N-methylenebisacrylamide and acrylic acid toward the properties of Dioscorea hispida-starch-based hydrogel

    Science.gov (United States)

    Ashri, Airul; Lazim, Azwan

    2014-09-01

    The research investigated the effects of acrylic acid (monomer) and N,N,-methylenebisacrylamide, MBA (crosslinker) toward the percentage of gel content, swelling ratio and ionic strength of a starch-based hydrogel. Starch grafted on poly (sodium acrylate), St-g-PAANa hydrogel was prepared by incorporating starch extracted from Dioscorea hispida in NaOH/aqueous solution using different composition of acrylic acid (AA) and N,N-methylenebisacrylamide (MBA) in the presence of potassium persulfate (KPS) as chemical initiator. The highest gel content was observed at 1:30 ratio of starch to AA and 0.10 M of MBA. Results showed the highest swelling ratio was observed at 1:15 ratio of starch to acrylic acid and 0.02 M of MBA solution. The same results also gave the highest swelling ratio for the ionic strength study. The FTIR analysis was also conducted in order to confirm the grafting of AA onto starch backbone.

  12. Molecular assembly, interfacial rheology and foaming properties of oligofructose fatty acid esters.

    Science.gov (United States)

    van Kempen, Silvia E H J; Schols, Henk A; van der Linden, Erik; Sagis, Leonard M C

    2014-01-01

    Two major types of food-grade surfactants used to stabilize foams are proteins and low molecular weight (LMW) surfactants. Proteins lower the surface tension of interfaces and tend to unfold and stabilize the interface by the formation of a visco-elastic network, which leads to high surface moduli. In contrast, LMW surfactants lower the surface tension more than proteins, but do not form interfaces with a high modulus. Instead, they stabilize the interface through the Gibbs-Marangoni mechanism that relies on rapid diffusion of surfactants, when surface tension gradients develop as a result of deformations of the interface. A molecule than can lower the surface tension considerably, like a LMW surfactant, but also provide the interface with a high modulus, like a protein, would be an excellent foam stabilizer. In this article we will discuss molecules with those properties: oligofructose fatty acid esters, both in pure and mixed systems. First, we will address the synthesis and structural characterization of the esters. Next, we will address self-assembly and rheological properties of air/water interfaces stabilized by the esters. Subsequently, this paper will deal with mixed systems of mono-esters with either di-esters and lauric acid, or proteins. Then, the foaming functionality of the esters is discussed.

  13. Unsaturated Fatty Acid Esters Metathesis Catalyzed by Silica Supported WMe5

    KAUST Repository

    Riache, Nassima

    2015-11-14

    Metathesis of unsaturated fatty acid esters (FAEs) by silica supported multifunctional W-based catalyst is disclosed. This transformation represents a novel route towards unsaturated di-esters. Especially, the self-metathesis of ethyl undecylenate results almost exclusively on the homo-coupling product whereas with such catalyst, 1-decene gives ISOMET (isomerization and metathesis olefin) products. The olefin metathesis in the presence of esters is very selective without any secondary cross-metathesis products demonstrating that a high selective olefin metathesis could operate at 150 °C. Additionally, a cross-metathesis of unsaturated FAEs and α-olefins allowed the synthesis of the corresponding ester with longer hydrocarbon skeleton without isomerisation.

  14. Esterification Reaction of Glycerol and Palm Oil Oleic Acid Using Methyl Ester Sulfonate Acid Catalyst as Drilling Fluid Formulation

    Science.gov (United States)

    Sari, V. I.; Hambali, E.; Suryani, A.; Permadi, P.

    2017-02-01

    Esterification reaction between glycerol with palm oil oleic acid to produce glycerol ester and one of the utilization of glycerol esters is as ingredients of drilling fluids formula for oil drilling needs. The purpose of this research is to get the best conditions of the esterification process. The esterification reaction does with the reactants is glycerol with purity of 97.6%, palm oil oleic acid with the molar ratio is 1:1, Methyl Ester Sulfonate Acid (MESA) catalyst 0.5%, and stirring speed 400 rpm. The temperature range of 180°C to 240°C and the processing time between 120 to 180 minutes. The results showed that the best conditions of the esterification reaction at the temperature 240°C and time process are 180 minute. The increasing temperature resulted that the acid number decreases and causing the conversion increased. The maximum conversion is 99.24%, density 0.93 g/cm3, flash point 241°C, pour point -3°C, the boiling point of 244 °C, the acid value of 1.90 mg KOH/g sample, kinematic viscosity 31.51 cSt (40°C), surface tension 37.0526 dyne/cm and GCMS identification, glycerol ester at 22,256 retention time (minutes) and wide area 73.75 (%). From the research results obtained glycerol ester with characteristics suitable for drilling fluid formulations.

  15. Study of Graft Copolymerization of Acrylic Acid Onto Nata De Coco and its Application as Microfiltration Membrane

    Directory of Open Access Journals (Sweden)

    T. Puspitasari

    2006-07-01

    Full Text Available Chemical and physical modifications of membrane can be carried out by radiation induced graft copolymerization. The aim of this research is to prepare graft copolymers of acrylic acid onto nata de coco (NDC-g-AAc by radiation and to study the performance of grafted copolymer as microfiltration membrane. Using a total dose of 30 kGy, the highest degree of grafting obtained were 209% and 142% for r (weight ratio of monomers to nata de coco equal to 61.3 and 35.7 respectively. The increasing degree of grafting resulted in decreasing flux due to high hydrogen bonding between grafted acrylic groups and water. It was found that the degree of swelling of NDC-g-AAc membrane with r = 35.7 was higher than that of r = 63.1. The changes of chemical structure of membrane were characterized by FTIR spectroscopy which showed a new band at 1720 cm-1 attributed to the carbonyl group of acrylic acid

  16. Quantification of primary fatty acid amides in commercial tallow and tallow fatty acid methyl esters by HPLC-APCI-MS.

    Science.gov (United States)

    Madl, Tobias; Mittelbach, Martin

    2005-04-01

    Primary fatty acid amides are a group of biologically highly active compounds which were already identified in nature. Here, these substances were determined in tallow and tallow fatty acid methyl esters for the first time. As tallow is growing in importance as an oleochemical feedstock for the soap manufacturing, the surfactant as well as the biodiesel industry, the amounts of primary fatty acid amides have to be considered. As these compounds are insoluble in tallow as well as in the corresponding product e.g. tallow fatty acid methyl esters, filter plugging can occur. For the quantification in these matrices a purification step and a LC-APCI-MS method were developed. Although quantification of these compounds can be performed by GC-MS, the presented approach omitted any derivatization and increased the sensitivity by two orders of magnitude. Internal standard calibration using heptadecanoic acid amide and validation of the method yielded a limit of detection of 18.5 fmol and recoveries for the tallow and fatty acid methyl ester matrices of 93% and 95%, respectively. A group of commercially available samples were investigated for their content of fatty acid amides resulting in an amount of up to 0.54%m/m (g per 100 g) in tallow and up to 0.16%m/m (g per 100 g) in fatty acid methyl esters.

  17. The occurrence of 2-hydroxy-6-methoxybenzoic acid methyl ester in Securidaca longepedunculata Fresen root bark

    Directory of Open Access Journals (Sweden)

    Lognay G.

    2000-01-01

    Full Text Available As part of our ongoing search for natural fumigants from Senegalese plants, we have investigated Securicicidaca longepedunculata root barks and demonstrated that 2-hydroxy-benzoic acid methyl ester (methyl salicylate, I is responsible of their biocide effect against stored grain insects. A second unknown apparented product, II has been systematically observed in all analyzed samples. The present paper describes the identification of this molecule. The analytical investigations including GCMS, GLC and 1H-NMR. spectrometry led to the conclusion that II corresponds to the 2-hydroxy-6-methoxybenzoic acid methyl ester.

  18. Synthesis of (S)-ricinoleic acid and its methyl ester with the participation of ionic liquid.

    Science.gov (United States)

    Kula, Józef; Bonikowski, Radoslaw; Szewczyk, Malgorzata; Ciolak, Kornelia

    2014-10-01

    (R)-ricinoleic acid methyl ester obtained from commercial castor oil was transformed in a three-step procedure into its S-enantiomer in overall 36% yield using ionic liquid (1-butyl-3-methylimidazolium acetate) in the key step process. The developed procedure provides easy access to (S)-ricinoleic acid and its methyl ester of over 95% enantiomeric excess. Optical rotations of the newly obtained compounds as well as their chromatographic and spectral characteristics are provided and discussed in the context of enantiopurity both of the substrate material and the final products.

  19. Scalable preparation of high purity rutin fatty acid esters following enzymatic synthesis

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

    2010-01-01

    Investigations into expanded uses of modified flavonoids are often limited by the availability of these high purity compounds. As such, a simple, effective and relatively fast method for isolation of gram quantities of both long and medium chain fatty acid esters of rutin following scaled-up bios...... following a two-step solvent purification procedure whereby excess fatty acid substrate was first removed in a heptane/water (4:1, v/v) system, followed by selective ester extraction using an ethyl acetate/water system (1:6, v/v) at elevated temperature....

  20. Effect of sugar fatty acid esters on rumen fermentation in vitro

    OpenAIRE

    Wakita, M; Hoshino, S.

    1987-01-01

    1.The effect of sugar fatty acid esters (SFEs; currently used as food additives for human consumption) on rumen volatile fatty acids (VFA) and gas production was studied with sheep rumen contents in vitro.2. Some SFEs having monoester contents of more than 70% increased the molar proportion of propionate in conjunction with reduction in the acetate: propionate ratio when the individual SFE was added to rumen contents in a final concentration of 4 g/l. Laurate sugar ester was the most potent p...

  1. Characterization and properties of a polythiophene with a malonic acid dimethyl ester side group

    OpenAIRE

    Armelín Diggroc, Elaine Aparecida; Bertran Cànovas, Òscar; Estrany Coda, Francesc; Salvatella, Roser; Alemán Llansó, Carlos

    2009-01-01

    A new polythiophene derivative bearing a malonic acid dimethyl ester substituent attached to the 3-position of the repeat unit has been prepared by chemical oxidative-coupling polymerization. The chemical structure of poly(2-thiophen-3-yl-malonic acid dimethyl ester) has been analyzed by FTIR and 1H NMR spectroscopy and, additionally, the distribution of the head-to-tail and head-to-head diads arising from polymerization was found to be a 75–25%. The glass transition temperature identified fo...

  2. Anticancer Activities of Substituted Cinnamic Acid Phenethyl Esters on Human Cancer Cell Lines

    Institute of Scientific and Technical Information of China (English)

    LIShu-chun; LIHui; ZHANGFa; LIZhong-jun; CUIJing-rong

    2003-01-01

    Caffeic acid phenethyl ester (CAPE) and sixteen substituted cinnamic acid phenethyl esters were prepared via conventional procedures in order to test their in vitro anticancer activities by either MTT assay or SRB assay on six different human cancer cell lines. The results indicated that in the concentration of 10μmol·L-1 the lead compmuM CAPE possessed anficancer activities against human HL-60, Bel-7402, and Hela cell lines, and two other compounds possessed potent anticancer activities against Bel-7402 and Hela cell lines.

  3. Antifungal properties of 2-bromo-3-fluorosuccinic acid esters and related compounds.

    Science.gov (United States)

    Gershon, H; Shanks, L

    1977-04-01

    Twelve esters (C1-C6) of erythro- and threo-2-bromo-3-fluorosuccinic acid and related compounds were tested for antifungal activity against Candida albicans, Aspergillus niger, Mucor mucedo, and Trichophyton mentagrophytes at pH 5.7 and 7.0 in the absence and presence of 10% beef serum in Sabouraud dextrose agar. At pH 7.0 in the presence of 10% beef serum, no consistent pattern in the fungitoxicity of the erythro- and threo-2-bromo-3-fluorosuccinate esters was seen. Increasing the length of the ester function affects fungitoxicity as follows: C2 greater than C1 greater than C3 greater than C4 greater than C5 greater than C6. The most fungitoxic compound in this study was threo-ethyl 2-bromo-3-fluorosuccinate (C. albicans, 14 mug/ml; A. niger, 30 mug/ml; M. mucedo, 9 mug/ml; T. mentagrophytes, 5 mug/ml). Due to the ease of dehydrohalogenation, the fungitoxicity of 2-bromo-3-fluorosuccinic acid esters may be the result of a mixture composed of the parent compound, the bromo- and fluorofumaric acid esters, and HF and HBr of which part may be formed extracellularly and part within the cell.

  4. Synthesis of sulfur-containing lubricant additives on the basis of fatty acid ethyl esters

    Directory of Open Access Journals (Sweden)

    Iurii S. Bodachivskyi

    2016-12-01

    Full Text Available The study reveals an energy-, resource- and eco-friendly method for preparation of sulfur-containing lubricant additives via interaction of fatty acid ethyl esters of rapeseed oil with elemental sulfur. The structure of synthesized compounds under various reactants ratio (5–50 wt.% of sulfur, duration (30–240 min and temperature of the process (160–215°С was investigated using various analytical techniques. According to the established data, aside from addition to double bonds, the side reaction of hydrogen substitution at α-methylene groups near these bonds occurs and induces the formation of conjugated systems and chromophoric sulfur-rich derivatives. Also, we found that increase of process duration evokes growth of polysulfane chains, in contrast to the raise of temperature, which leads to the formation of sulfur-containing heterocycles and hydrogen sulfide, as a result of elimination. Influence of accelerators on sulfurization of fatty acid ethyl esters was also examined. The most effective among them are mixtures of zinc dibutyldithiocarbamate with zinc oxide or stearic acid, which soften synthesis conditions and doubly decrease duration of the high-temperature stage. In addition, sulfur-containing compositions of ethyl esters and α-olefins, vulcanized esters by benzoyl peroxide, nonylphenols and zinc dinonylphenyldithiophosphate were designed. The study identified that lithium lubricant with sulfurized vulcanized esters provides improved tribological properties, in comparison with base lubricant or lubricant with the non-modified product.

  5. Chelation in Metal Intoxication XLVI:Synthesis of Some α-Mercapto-β-Substituted Aryl Acrylic Acids and Their In vitro Cadmium Chelating Ability

    Institute of Scientific and Technical Information of China (English)

    MADHUMITA CHATTERJEE; VINOD K. DWIVEDI; KIRTI KHANDEKAR; SUSHIL K. TANDON

    2004-01-01

    Objective To synthesize some new α-mercapto-β-substituted aryl acrylic acids, characterize them and investigate their in vitro cadmium chelating ability. Methods Six α-mercapto-β-substituted aryl acrylic acids were prepared by the alkaline hydrolysis of 5-(aryl methylene)rhodanines, obtained from the condensation of substituted aldehydes and rhodanine following the reported procedure. The new compounds were characterized by elemental analysis, infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy. The liver and kidney from cadmium chloride pre-administered rats were homogenized and their nuclear mitochondrial fraction (NMF) and supernatant cytosol fraction (SCF) were separated. A measured volume of each fraction was dialyzed separately using "dialysis sack" against buffered-KCl medium containing a compound in the final concentration of 1×10-3 mol/L for 3 h at 37℃C. The whole content of "sack" was subjected to cadmiumestimation following digestion with conc. Nitric acid was detected using flame atomic absorption spectrometer. Results The in vitro screening showed that α-mercapto-β-(p-methoxyphenyl)acrylic acid (compound 2) and α-mercapto-β-(m-methoxy, p-hydroxyphenyl) acrylic acid (compound 4) were more effective than α-mercapto-β-thienyl acrylic acid (compound 1) and α-mercapto-β-(p-dimethylaminophenyl) acrylic acid (compound 3) in mobilizing cadmium as their dialyzable chelates. The presence of a methoxy group on the phenyl moiety (compounds 2 and 4) increases the metal chelating ability of mercapto acrylic acids. Conclusions Compounds 2 and 4 seem to have accessibility to the cellular system and capability of chelating-out the intracellularly bound cadmium.

  6. Fracture Mechanisms of Layer-By-Layer Polyurethane/Poly(Acrylic Acid) Nanocomposite

    Science.gov (United States)

    Kheng, Eugene R.

    A layer-by-layer(LBL) manufactured material is examined in detail in this thesis. Improvements are made to the method of its manufacture. Efforts are made to understand its fracture mechanisms and take advantage of these fracture mechanisms in the absorption of impact energy. A novel series of experiments has been performed on LBL manufactured thin films to demonstrate their unique fracture mechanisms. Polyurethane/Poly(Acrylic Acid) (PU/PAA) and PU/PAA/(PU/Clay)5 nanocomposite films readily undergo Interlaminar mode II fracture, because of the relatively weak elctrostatic bonds between monolayers. Tensile tests performed while under observation by a scanning electron microscope demonstrate the tendency of these nanocomposite films to undergo interlaminar mode II fracture even when loads are applied in the plane of nanocomposite film. It is concluded that these mechanisms of energy dissipation are responsible for the enhanced toughness of these films when used as layers between glass blocks in the prevention of impact damage to the glass. A novel automated manufacturing facility has been designed and built to deposit large sheets of Layer-by-Layer nanocomposite film. These large sheets are incorporated into a borosillicate glass composite in order to compare the ballistic characteristics of LBL PU based nanocomposite films to a single cast layer of polyurethane. It is demonstrated that shear fracture is the mode of failure in the blocks containing the nanocomposite film. The shear fracture surface in the nanocomposite after it has undergone a ballistic impact is characterized. Additional experiments are performed to characterize the interlaminar fracture stresses and toughnesses of the nanocomposite LBL layers, to assist in the implementation of a numerical crack band model that describes the nanocomposite film. The computational model predicts the failure of the ballistic nanocomposite samples, and the predicted V50 velocity is found to be in good agreement with

  7. Transport in Porous Media of Poly(Acrylic Acid) Coated Ferrihydrite Nanoparticles

    Science.gov (United States)

    Jaffe, P. R.; Xiang, A.; Koel, B. E.

    2012-12-01

    Augmentation of soils with iron to enhance biological processes such as uranium reduction via iron reducing bacteria, e.g., Geobacter sp., might be achieved via the injection of iron nanoparticles into the subsurface. The challenge is to make these nanoparticles transportable in the subsurface while not affecting the iron bioavailability. Poorly crystallized 2-line ferrihydrite iron oxide nanoparticles were synthesized and coated with different amounts of poly(acrylic acid) polymers (Na-PAA6K or Na-PAA140K). Analyses were then performed on these particles, including sorption/desorption of the polymer onto the iron nanoparticles, particle size, zeta potential, transport in sand and soil columns, and bioavailabity of the Fe(III) in the absence and presence of the coating to iron reducing organisms. Results showed that at pH values of environmental relevance, the zeta potential of the particles varied from about 3 mV (pH=8.2) for the non-coated particles to about -30 mV for the particles coated with the polymers to their highest sorption capacity. The coated particle diameter was shown to be in the range of 200 nm. Column transport experiments showed that for the highest polymer coating the nanoparticle breakthrough was virtually identical to that of bromide, while significant filtration was observed for particles with an intermediate coating, and complete particle removal via filtration was observed for the non-coated particles. These results held for sand as well as for soil, which had been previously characterized, from a field site at Rifle, CO. Bioavailability experiments showed no difference in the iron reduction rate between the untreated and treated nanoparticles. These results show that it is possible to manufacture iron nanoparticles to enhance biological iron reduction, and that the transport properties of these treated particles is tunable so that a desired retention in the porous medium can be achieved.

  8. Fabrication and mechanical characterization of graphene oxide-reinforced poly (acrylic acid)/gelatin composite hydrogels

    Science.gov (United States)

    Faghihi, Shahab; Gheysour, Mahsa; Karimi, Alireza; Salarian, Reza

    2014-02-01

    Hydrogels have found many practical uses in drug release, wound dressing, and tissue engineering. However, their applications are restricted due to their weak mechanical properties. The role of graphene oxide nanosheets (GONS) as reinforcement agent in poly (acrylic acid) (PAA)/Gelatin (Gel) composite hydrogels is investigated. Composite hydrogels are synthesized by thermal initiated redox polymerization method. Samples are then prepared with 20 and 40 wt. % of PAA, an increasing amount of GONS (0.1, 0.2, and 0.3 wt. %), and a constant amount of Gel. Subsequently, cylindrical hydrogel samples are subjected to a series of compression tests in order to measure their elastic modulus, maximum stress and strain. The results exhibit that the addition of GONS increases the Young's modulus and maximum stress of hydrogels significantly as compared with control (0.0 wt. % GONS). The highest Young's modulus is observed for hydrogel with GO (0.2 wt. %)/PAA (20 wt. %), whereas the highest maximum stress is detected for GO (0.2 wt. %)/PAA (40 wt. %) specimen. The addition of higher amounts of GONS leads to a decrease in the maximum stress of the hydrogel GO (0.3 wt. %)/PAA (40 wt. %). No significant differences are detected for the maximum strain among the hydrogel samples, as the amount of GONS increased. These results suggest that the application of GONS could be used to improve mechanical properties of hydrogel materials. This study may provide an alternative for the fabrication of low-cost graphene/polymer composites with enhanced mechanical properties beneficial for tissue engineering applications.

  9. Spray-On Polyaniline/Poly(acrylic acid) Electrodes with Enhanced Electrochemical Stability.

    Science.gov (United States)

    Jeon, Ju-Won; Kwon, Se Ra; Li, Fei; Lutkenhaus, Jodie L

    2015-11-04

    Polyaniline (PANI)-based electrodes are promising candidates for energy storage, but their cycle life remains poor. Recent work suggests that secondary interactions may enhance polyaniline's electrochemical stability and cycle life, but evidence to date is not conclusive. Here, we investigate spray-assisted layer-by-layer assemblies containing polyaniline nanofibers (PANI NFs) or conventional PANI and poly(acrylic acid) (PAA), which provides hydrogen bonding and electrostatic interactions. This spray-on approach may be suitable for the deposition of PANI onto a variety of surfaces. The effects of PANI type, PAA pH, and PAA molecular weight on the growth behavior, conductivity, and electrochemical performance are examined. It is shown that LbL films with PANI NFs, higher molecular weight PAA, and lower PAA pH yield the thickest films, whereas the thinnest films come from conventional PANI assembled under similar conditions. Electron microscopy imaging and density measurements show that LbL films containing PANI NFs are very porous, whereas those containing conventional PANI are very dense (0.28 vs 1.33 g/cm(3), respectively). The difference in density dramatically affects the electrochemical properties in terms of capacity and long-term cycling behavior. Upon extended cycling, PANI NFs alone rapidly lose their electrochemical activity. On the other hand, PANI NF-based LbL films exhibited somewhat enhanced stability, and PANI-based LbL films were exceptionally stable, maintaining 94.7% of their capacity after 1000 cycles when cycled up to 4.2 V vs Li/Li(+). These results show that secondary interactions from PAA enhance stability, as does the selection of PANI type and the electrode's density.

  10. Preparation of 9-hydroxynonanoic acid methyl ester by ozonolysis of vegetable oils and its polycondensation

    Directory of Open Access Journals (Sweden)

    Cvetković Ivana

    2008-01-01

    Full Text Available Vegetable oil-based and potentially biodegradable polyesters were prepared from 9-hydroxynonanoic acid methyl ester. This paper describes ozonolysis of vegetable oils and the method for preparation of useful monomers and in particular 9-hydroxynonanoic acid methyl ester. Ozonolysis of soybean oil and castor oil in methanol and methylene chloride solution, followed by reduction with sodium borohydride was used to obtain a mixture of triols, diols and monols. Triglyceride triols were separated from the rest of the mixture and transesterified with methanol to obtain methyl esters of fatty acids and glycerin. The main component of fatty acids was 9-hydroxynonanoic acid methyl ester, which was characterized and used for polycondensation by transesterification. High molecular weight polyhydroxy alcanoate was a solid having a melting point of 75°C. The molecular weight of the resulting polyester was affected by the purity of the monomer and side reactions such as cyclization. The polymer was characterized by chromatographic, thermal and analytical methods.

  11. Ionic liquids as novel solvents for the synthesis of sugar fatty acid ester.

    Science.gov (United States)

    Mai, Ngoc Lan; Ahn, Kihun; Bae, Sang Woo; Shin, Dong Woo; Morya, Vivek Kumar; Koo, Yoon-Mo

    2014-12-01

    Sugar fatty acid esters are bio-surfactants known for their non-toxic, non-ionic, and high biodegradability . With great emulsifying and conditioning effects, sugar fatty acids are widely used in the food, pharmaceutical, and cosmetic industries. Biosynthesis of sugar fatty acid esters has attracted growing attention in recent decades. In this study, the enzymatic synthesis of sugar fatty acid esters in ionic liquids was developed, optimized, and scaled up. Reaction parameters affecting the conversion yield of lipase-catalyzed synthesis of glucose laurate from glucose and vinyl laurate (i.e. temperature, vinyl laurate/glucose molar ratio, and enzyme loads) were optimized by response surface methodology (RSM). In addition, production was scaled up to 2.5 L, and recycling of enzyme and ionic liquids was investigated. The results showed that under optimal reaction conditions (66.86 °C, vinyl laurate/glucose molar ratio of 7.63, enzyme load of 73.33 g/L), an experimental conversion yield of 96.4% was obtained which is close to the optimal value predicted by RSM (97.16%). A similar conversion yield was maintained when the reaction was carried out at 2.5 L. Moreover, the enzymes and ionic liquids could be recycled and reused effectively for up to 10 cycles. The results indicate the feasibility of ionic liquids as novel solvents for the biosynthesis of sugar fatty acid esters.

  12. Synthesis and Structural Characterization of 1- and 2-Substituted Indazoles: Ester and Carboxylic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Isabel Bento

    2006-11-01

    Full Text Available A series of indazoles substituted at the N-1 and N-2 positions with ester-containing side chains -(CH2nCO2R of different lengths (n = 0-6, 9, 10 are described.Nucleophilic substitution reactions on halo esters (X(CH2nCO2R by 1H-indazole inalkaline solution lead to mixtures of N-1 and N-2 isomers, in which the N-1 isomerpredominates. Basic hydrolysis of the ester derivatives allowed the synthesis of thecorresponding indazole carboxylic acids. All compounds were fully characterised bymultinuclear NMR and IR spectroscopies, MS spectrometry and elemental analysis; theNMR spectroscopic data were used for structural assignment of the N-1 and N-2 isomers.The molecular structure of indazol-2-yl-acetic acid (5b was determined by X-raydiffraction, which shows a supramolecular architecture involving O2-H...N1intermolecular hydrogen bonds.

  13. 21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diacetyl tartaric acid esters of mono- and... Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils,...

  14. 21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Methyl esters of conjugated linoleic acid (cis-9... § 573.637 Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic acids). The food additive, methyl esters of conjugated linoleic acid (cis-9, trans-11 and...

  15. Substituent effects and pH profiles for stability constants of arylboronic acid diol esters.

    Science.gov (United States)

    Martínez-Aguirre, Mayte A; Villamil-Ramos, Raul; Guerrero-Alvarez, Jorge A; Yatsimirsky, Anatoly K

    2013-05-17

    Stability constants of boronic acid diol esters in aqueous solution have been determined potentiometrically for a series of meta-, para-substituted phenylboronic acids and diols of variable acidity. The constants β(11-1) for reactions between neutral forms of reactants producing the anionic ester plus proton follow the Hammett equation with ρ depending on pKa of diol and varying from 2.0 for glucose to 1.29 for 4-nitrocatechol. Observed stability constants (K(obs)) measured by UV-vis and fluorometric titrations at variable pH for esters of 4,5-dihydroxy-1,3-benzenedisulfonate (Tiron) generally agree with those expected on the basis of β(11-1) values, but the direct fitting of K(obs) vs pH profiles gives shifted pKa values both for boronic acids and diol as a result of significant interdependence of fitting parameters. The subsituent effects on absorption and fluorescence spectra of Tiron arylboronate esters are characterized. The K(obs) for Tiron determined by (11)B NMR titrations are approximately 1 order of magnitude smaller than those determined by UV-vis titrations under identical conditions. A general equation, which makes possible an estimate of β(11-1) for any pair of boronic acid and diol from their pKa values, is proposed on the basis of established Brönsted-type correlation of Hammett parameters for β(11-1) with acidity of diols. The equation allows one to calculate stability constants expected only on basis of acid-base properties of the components, thus permitting more strict evaluation of contributions of additional factors such as steric or charge effects to the ester stability.

  16. 40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Octadecanoic acid, ester with 1,2..., ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as octadecanoic acid,...

  17. Synthesis and evaluation of odour-active methionyl esters of fatty acids via esterification and transesterification of butter oil.

    Science.gov (United States)

    Li, Cheng; Sun, Jingcan; Fu, Caili; Yu, Bin; Liu, Shao Quan; Li, Tianhu; Huang, Dejian

    2014-02-15

    Methionol-derived fatty acid esters were synthesised by both chemical and lipase catalysed esterification between fatty acids and methionol. Beneficial effects of both methods were compared qualitatively and quantitatively by GC-MS/GC-FID results. And the high acid and heat stability of our designed methionyl esters meet the requirement of the food industry. Most importantly, the sensory test showed that fatty acid carbon-chain length had an important effect on the flavour attributes of methionyl esters. Moreover, through Lipozyme TL IM-mediated transesterification, valuable methionol-derived esters were synthesised from the readily available natural material butter oil as the fatty acid source. The conversion of methionol and yield of each methionyl ester were also elucidated by GC-MS-FID.

  18. Fatty acid esters of monochloropropanediol (MCPD) and glycidol in refined edible oils.

    Science.gov (United States)

    Craft, B D; Chiodini, A; Garst, J; Granvogl, M

    2013-01-01

    Recently, fatty acid esters of monochloropropanediol (MCPD) and that of glycidol have been reported in refined edible oils. Since then a wealth of research has been published on the factors influencing the formation of these contaminants in foods. It can be noted that the predominant precursors in a given matrix will not necessarily be the same as in other matrices. Further, proven relationships in the past between precursors responsible for free MCPD or free glycidol formation will not necessarily be valid for their fatty acid-esterified counterparts. This review attempts to summarise the current status of the literature as it pertains to the reasons surrounding the manifestation of MCPD esters and glycidyl esters in oils and fats. Recent efforts to mitigate the levels of these contaminants were highlighted and put into the context of their respective reaction matrices. As more accurate occurrence data for MCPD esters and glycidyl esters in other foods are collected, more targeted mitigation experiments can be formulated with respect to the reaction matrices under investigation.

  19. Hydrophobically Modified Polyelectrolytes: V. Interaction of Fluorocarbon Modified Poly (acrylic acid) with Various Added Surfactants

    Institute of Scientific and Technical Information of China (English)

    ZHOU,Hui(周晖); SONG,Guo-Qaiang(宋国强); GUO,Jin-Feng(郭金峰); ZHANG,Yun-xiang (章云祥); DIEING,Reinhold; MA,Lian(马莲); HAEUSSLING,Lukas

    2001-01-01

    The interactions between fiuorocarbon-medified pol(sodium acrylate) and various kinds of added surfactant have been studied by means of viscometric measurement. Association behavior was found in both hydrogenated and fluorinated anionic, nonionic and cationic surfactants. Among them, the interactions between fluorocarbon-modified poly ( sodium acrylate) and cationic surfactants are the strongest, owing to the cooperation of both electrostatic attractions and hydrophobic associations. The anionic surfactants have the weakest effects on the solution properties because of the existence of unfavorable electrostatic repulsion. The hydrophobic interactions between copolymers and fluorinated surfactants are much stronger than those between copolymers and hydrogenated surfactants.

  20. Synthesis and characterization of biodegradable polymer: Poly (ethene maleic acid ester-co-D,L-lactide acid)

    Institute of Scientific and Technical Information of China (English)

    Mei Na Huang; Yan Feng Luo; Jia Chen; Yong Gang Li; Chun Hua Fu; Yuan Liang Wang

    2007-01-01

    A novel biodegradable polymer-poly (ethene maleic acid ester-co-D,L-lactide acid) was synthesized by copolymerizing lactide and prepolymer, which was prepared by the condensation of maleic anhydride and glycol, using p-toluene sulphonic acid as a catalyst, attempting to improve the hydrophilicity, increase flexibility and modulate the degradation rate. FTIR, 1H NMR, MALLS and DSC were employed to characterize these polymers.

  1. Microbial dynamics in anaerobic enrichment cultures degrading di-n-butyl phthalic acid ester

    DEFF Research Database (Denmark)

    Trably, Eric; Batstone, Damien J.; Christensen, Nina

    2008-01-01

    in enrichment cultures degrading phthalic acid esters under methanogenic conditions. A selection pressure was applied by adding DBP at 10 and 200 mg L(-1) in semi-continuous anaerobic reactors. The microbial dynamics were monitored using single strand conformation polymorphism (SSCP). While only limited abiotic...

  2. Cold flow properties of fatty acid methyl esters: Additives versus diluents

    Science.gov (United States)

    Biodiesel is typically composed of fatty acid methyl esters (FAME) converted from agricultural lipids. Common feedstocks include soybean oil, canola oil, rapeseed oil, sunflower oil, and palm oil. Recent debate on the conversion of edible oils into non-food products has created opportunities to deve...

  3. Evaluation of Mosquito Repellent Activity of Isolated Oleic Acid, Eicosyl Ester from Thalictrum javanicum

    Science.gov (United States)

    Gurunathan, Abinaya; Senguttuvan, Jamuna; Paulsamy, S.

    2016-01-01

    To evaluate the traditional use, the mosquito repellent property of Thalictrum javanicum and to confirm the predicted larvicidal activity of the isolated compound, oleic acid, eicosyl ester from its aerial parts by PASS software, the present study was carried out using 4th instar stage larvae of the mosquitoes, Aedes aegypti (dengue vector) and Culex quinquefasciatus (filarial vector). Insecticidal susceptibility tests were conducted and the mortality rate was observed after 24 h exposure. The chitinase activity of isolated compound was assessed by using purified β-N-acetyl glucosaminidase (chitinase). Ecdysone 20-monooxygenase assay (radioimmuno assay) was made using the same larval stage of A. aegyptiand C. quinquefasciatus. The results were compared with the crude methanol extract of the whole plant. The isolated compound, oleic acid, eicosyl ester was found to be the most effective larvicide against A. aegypti (LC50/24 h -8.51 ppm) and C. quinquefasciatus (LC50/24 h - 12.5 ppm) than the crude methanol extract (LC50/24 h - 257.03 ppm and LC50/24 h - 281.83 ppm, respectively). The impact of oleic acid, eicosyl ester on reducing the activity of chitinase and ecdysone 20-monooxygenase was most prominent in both the target species, A. aegyptiand C. quinquefasciatus than the control. The results therefore suggest that the compound, oleic acid, eicosyl ester from Thalictrum javanicum may be considered as a potent source of mosquito larvicidal property. PMID:27168688

  4. Beyond fatty acid methyl esters: Expanding the renewable carbon profile with alkenones from Isochrysis sp.

    Science.gov (United States)

    In addition to characteristic fatty acid methyl esters (FAMEs), biodiesel produced from Isochrysis sp. contains a significant amount (14% dry weight) of predominantly C37 and C38 longchain alkenones. These compounds are members of a class of lipids known collectively as polyunsaturated long-chain al...

  5. Evaluation of Mosquito Repellent Activity of Isolated Oleic Acid, Eicosyl Ester from Thalictrum javanicum.

    Science.gov (United States)

    Gurunathan, Abinaya; Senguttuvan, Jamuna; Paulsamy, S

    2016-01-01

    To evaluate the traditional use, the mosquito repellent property of Thalictrum javanicum and to confirm the predicted larvicidal activity of the isolated compound, oleic acid, eicosyl ester from its aerial parts by PASS software, the present study was carried out using 4th instar stage larvae of the mosquitoes, Aedes aegypti (dengue vector) and Culex quinquefasciatus (filarial vector). Insecticidal susceptibility tests were conducted and the mortality rate was observed after 24 h exposure. The chitinase activity of isolated compound was assessed by using purified β-N-acetyl glucosaminidase (chitinase). Ecdysone 20-monooxygenase assay (radioimmuno assay) was made using the same larval stage of A. aegyptiand C. quinquefasciatus. The results were compared with the crude methanol extract of the whole plant. The isolated compound, oleic acid, eicosyl ester was found to be the most effective larvicide against A. aegypti (LC50/24 h -8.51 ppm) and C. quinquefasciatus (LC50/24 h - 12.5 ppm) than the crude methanol extract (LC50/24 h - 257.03 ppm and LC50/24 h - 281.83 ppm, respectively). The impact of oleic acid, eicosyl ester on reducing the activity of chitinase and ecdysone 20-monooxygenase was most prominent in both the target species, A. aegyptiand C. quinquefasciatus than the control. The results therefore suggest that the compound, oleic acid, eicosyl ester from Thalictrum javanicum may be considered as a potent source of mosquito larvicidal property.

  6. Evaluation of mosquito repellent activity of isolated oleic acid, eicosyl ester from Thalictrum javanicum

    Directory of Open Access Journals (Sweden)

    Abinaya Gurunathan

    2016-01-01

    Full Text Available To evaluate the traditional use, the mosquito repellent property of Thalictrum javanicumand to confirm the predicted larvicidal activity of the isolated compound, oleic acid, eicosyl ester from its aerial parts by PASS software, the present study was carried out using 4th instar stage larvae of the mosquitoes, Aedes aegypti(dengue vector and Culex quinquefasciatus(filarial vector. Insecticidal susceptibility tests were conducted and the mortality rate was observed after 24 h exposure. The chitinase activity of isolated compound was assessed by using purified β-N-acetyl glucosaminidase (chitinase. Ecdysone 20-monooxygenase assay (radioimmuno assay was made using the same larval stage of A. aegyptiand C. quinquefasciatus. The results were compared with the crude methanol extract of the whole plant. The isolated compound, oleic acid, eicosyl ester was found to be the most effective larvicide against A. aegypti (LC50/24 h -8.51 ppm and C. quinquefasciatus (LC50/24 h - 12.5 ppm than the crude methanol extract (LC50/24 h - 257.03 ppm and LC50/24 h - 281.83 ppm, respectively. The impact of oleic acid, eicosyl ester on reducing the activity of chitinase and ecdysone 20-monooxygenase was most prominent in both the target species, A. aegyptiand C. quinquefasciatusthan the control. The results therefore suggest that the compound, oleic acid, eicosyl ester from Thalictrum javanicummay be considered as a potent source of mosquito larvicidal property.

  7. SEPARATION OF T-MAZ ETHOXYLATED SORBITAN FATTY ACID ESTERS BY SUPERCRITICAL FLUID CHROMATOGRAPHY

    Science.gov (United States)

    The application of supercritical fluid chromatography (SFC) to the analysis of T-MAZ ethoxylated sorbitan fatty acid esters is described. FC separation methods utilize a density programming technique and a 50 um I.D. capillary column. his work demonstrates that capillary column S...

  8. Drug-induced Fanconi syndrome associated with fumaric acid esters treatment for psoriasis: A case series

    NARCIS (Netherlands)

    D.M.W. Balak (Deepak); J.N.B. Bavinck (Jan Nico Bouwes); De Vries, A.P.J. (Aiko P. J.); Hartman, J. (Jenny); Martino Neumann, H.A. (Hendrik A.); R. Zietse (Bob); H.B. Thio (Bing)

    2016-01-01

    textabstractBackground: Fumaric acid esters (FAEs), an oral immunomodulating treatment for psoriasis and multiple sclerosis, have been anecdotally associated with proximal renal tubular dysfunction due to a drug-induced Fanconi syndrome. Few data are available on clinical outcomes of FAE-induced Fan

  9. Esterification and transesterification of greases to fatty acid methyl esters with highly active diphanylammonium salts

    Science.gov (United States)

    We have conducted an investigation designed to identify alternate catalysts for the production of fatty acid methyl esters (FAME) to be used as biodiesel. Diphenylammonium sulfate (DPAS) and diphenylammonium chloride (DPA-HCl) salts were found to be highly active homogeneous catalysts for the simu...

  10. Esterification and Transesterification of greases to fatty acid methyl esters with highly active diphenylamine salts

    Science.gov (United States)

    Diphenylamine sulfate (DPAS) and diphenylamine hydrochloride (DPACl) salts were found to be highly active catalysts for esterification and transesterification of inexpensive greases to fatty acid methyl esters (FAME). In the presence of catalytic amounts of DPAS or DPACl and excess methanol, the fr...

  11. Chemically modified fatty acid methyl esters: their potential for use as lubrication fluids and surfactants

    Science.gov (United States)

    A review of recent developments in the synthesis and characterization of lubrication fluids and surfactants from methyl oleate. The synthesis of materials made using an epoxidation route is the focus. This versatile method of chemical modification of fatty acid methyl esters improves their oxidati...

  12. Low-temperature side-chain cleavage and decarboxylation of polythiophene esters by acid catalysis

    DEFF Research Database (Denmark)

    Søndergaard, Roar; Norrman, Kion; Krebs, Frederik C

    2012-01-01

    Solubility switching of polymers is very useful in thin layer processing of conjugated polymers, as it allows for multilayer processing and increases the stability of the polymer. Acid catalyzed thermocleavage of ester groups from thiophene polymers carrying primary, secondary, and tertiary subst...

  13. Synthesis and antiproliferative activity of new bioconjugates of Salinomycin with amino acid esters.

    Science.gov (United States)

    Antoszczak, Michał; Sobusiak, Maria; Maj, Ewa; Wietrzyk, Joanna; Huczyński, Adam

    2015-09-01

    New Salinomycin (SAL) bioconjugates with amino acid methyl esters were obtained and their antiproliferative activity against cancer cell lines including drug-resistant ones was studied. New compounds exhibit antiproliferative activity towards leukemia and doxorubicin-resistant colon adenocarcinoma cell line and are more effective and less toxic than the commonly currently used anticancer drugs.

  14. ESTIMATION OF PHOSPHATE ESTER HYDROLYSIS RATE CONSTANTS. II. ACID AND GENERAL BASE CATALYZED HYDROLYSIS

    Science.gov (United States)

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate acid and neutral hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition states of a ...

  15. 4-[(2-Hydroxy-4-pentadecyl-benzylidene-amino]-benzoic Acid Methyl Ester

    Directory of Open Access Journals (Sweden)

    Gadada Naganagowda

    2013-11-01

    Full Text Available A new Schiff base, 4-[(2-hydroxy-4-pentadecyl-benzylidene-amino]-benzoic acid methyl ester was synthesized and its UV, IR, 1H-NMR, 13C-NMR and ESI-MS spectroscopic data are presented.

  16. Synthesis of Versatile Building Blocks through Asymmetric Hydrogenation of Functionalized Itaconic Acid Mono-Esters

    NARCIS (Netherlands)

    Hekking, Koen F.W.; Lefort, Laurent; Vries, André H.M. de; Delft, Floris L. van; Schoemaker, Hans E.; Vries, Johannes G. de; Rutjes, Floris P.J.T.

    2008-01-01

    The rhodium-catalyzed asymmetric hydrogenation of several β-substituted itaconic acid mono-esters, using a library of monodentate phosphoramidite and phosphite ligands is described. Two β-alkyl-substituted substrates were readily hydrogenated by the rhodium complex Rh(COD)2BF4 in combination with (S

  17. SYNTHESIS AND IN VITRO CHARACTERIZATION OF HYDROXYPROPYL METHYLCELLULOSE-GRAFT-POLY (ACRYLIC ACID/2-ACRYLAMIDO-2-METHYL-1-PROPANESULFONIC ACID) POLYMERIC NETWORK FOR CONTROLLED RELEASE OF CAPTOPRIL.

    Science.gov (United States)

    Furqan Muhammad, Iqbal; Mahmood, Ahmad; Aysha, Rashid

    2016-01-01

    A super-absorbent hydrogel was developed by crosslinking of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and acrylic acid with hydroxypropyl methylcellulose (HPMC) for controlled release drug delivery of captopril, a well known antihypertensive drug. Acrylic acid and AMPS were polymerized and crosslinked with HPMC by free radical polymerization, a widely used chemical crosslinking method. N,N'-methylenebisacrylamide (MBA) and potassium persulfate (KPS) were added as cross-linker and initiator, respectively. The hydrogel formulation was loaded with captopril (as model drug). The concentration of captopril was monitored at 205 nm using UV spectrophotometer. Equilibrium swelling ratio was determined at pH 2, 4.5 and 7.4 to evaluate the pH responsiveness of the formed hydrogel. The super-absorbent hydrogels were evaluated by FTIR, SEM, XRD, and thermal analysis (DSC and TGA). The formation of new copolymeric network was determined by FTIR, XRD, TGA and DSC analysis. The hydrogel formulations with acrylic acid and AMPS ratio of 4: 1 and lower amounts of crosslinker had shown maximum swelling. Moreover, higher release rate of captopril was observed at pH 7.4 than at pH 2, because of more swelling capacity of copolymer with increasing pH of the aqueous medium. The present research work confirms the development of a stable hydrogel comprising of HPMC with acrylic acid and AMPS. The prepared hydrogels exhibited pH sensitive behav-ior. This superabsorbent composite prepared could be a successful drug carrier for treating hypertension.

  18. Diels-Alder Reactions of α-Amido Acrylates with N-Cbz-1,2-dihydropyridine and Cyclopentadiene.

    Science.gov (United States)

    Abas, Hossay; Frampton, Christopher S; Spivey, Alan C

    2016-10-21

    Thermal Diels-Alder reactions of α-amido acrylates with N-Cbz-1,2-dihydropyridine and cyclopentadiene have been explored to investigate the factors influencing the endo/exo selectivity. For the dihydropyridine, steric factors allowed the diastereoselectivity to be modulated to favor either endo- or exo-ester adducts. For cyclopentadiene, the endo-ester adducts were favored regardless of steric perturbation, although catalysis by bulky Lewis acids increased the proportion of exo-ester adducts in some cases. These Lewis acids were incompatible with the dihydropyridine diene as they induced its decomposition.

  19. Potentiation of insulin release in response to amino acid methyl esters correlates to activation of islet glutamate dehydrogenase activity

    DEFF Research Database (Denmark)

    Kofod, Hans; Lernmark, A; Hedeskov, C J

    1986-01-01

    Column perifusion of mouse pancreatic islets was used to study the ability of amino acids and their methyl esters to influence insulin release and activate islet glutamate dehydrogenase activity. In the absence of L-glutamine, L-serine and the methyl ester of L-phenylalanine, but neither L...... glutamate dehydrogenase activity showed that only the two methyl esters of L-phenylalanine and L-serine activated the enzyme. It is concluded that the mechanism by which methyl esters of amino acids potentiate insulin release is most likely to be mediated by the activation of pancreatic beta-cell glutamate...

  20. Enzymatic production of fructose fatty acid ester using lipases from C. antarctica and porcine pancreatic

    OpenAIRE

    2009-01-01

    The aim of this work was to produce fructose fatty acid ester by enzymatic esterification of a fatty acid (oleic acid or linoleic acid) with fructose, using lipases (CALB) from Candida antarctica type B and porcine pancreas. The esterification reaction was conducted at 150 rpm and 40 °C during 72 hours. Equimolar (0.5 mmol) amounts of fructose and fatty acid were mixed with 0.6 ml of ethanol and sodium sulfate anhydrous (0.1 g) was added for the adsorption of the water generate...

  1. Advances in the Research and Development of Acrylic Acid Production from Biomass%从生物量生产丙烯酸的研究和开发进展

    Institute of Scientific and Technical Information of China (English)

    许晓波; 林建平; 岑沛霖

    2006-01-01

    The shortage of petroleum has resulted in worldwide efforts to produce chemicals from renewable resources. Among these attempts, the possibility of producing acrylic acid from biomass has caught the eye of many researchers. Converting the carbohydrates first to lactic acid by fermentation and then dehydrating lactic acid to acrylic acid is hitherto the most effective way for producing acrylic acid from biomass. While the lactic acid fermentation has been commercialized since longer times, the dehydration process of lactic acid is still under development because of its low yield. Further efforts should be made before this process became economically feasible.Because of the existence of acrylic acid pathways in some microorganisms, strain improvement and metabolic engineering provides also a possibility to produce acrylic acid directly from biomass by fermentation.

  2. SYNTHESIS OF POLY(DIVINYLBENZENE-co-ACRYLIC ACID) HOLLOW MICROSPHERES WITH GOLD NANOPARTICLES ON THE INTERIOR SURFACE

    Institute of Scientific and Technical Information of China (English)

    Wei Liu; Xin-lin Yang; Xu-gang He

    2009-01-01

    Poly(divinylbenzene-co-acrylic acid) (poly(DVB-co-AA)) hollow microspheres with gold nanoparticles on the interior surfaces were prepared from the gold nanoparticles-coated poly(methacrylic acid) (PMAA@Au@poly(DVB-co-AA)) core-shell microspheres by removal of the PMAA core in water.Au nanoparticles-coated PMAA microspheres were afforded by the in-situ reduction of gold trichloride with PMAA microsphere as stabilizer via the interaction between carboxylic acid groups and Au nanoparticles.Gold nanoparticles-coated (PMAA@Au@poly(DVB-co-AA)) microspheres were formed during the distillation precipitation copolymerization of divinylbenzene and acrylic acid in acetonitrile with Au-coated PMAA microspheres as seeds.The thickness of the poly(DVB-co-AA) shell-layer was controlled by the amount of the solvent distilled off the polymerization system.The PMAA microspheres,Au nanoparticles-coated PMAA microspberes,core-shell microspheres,and hollow microspheres with Au nanoparticles on the interior surfaces were studied by transmission electron microscopy and scanning electron microscopy.The stabilization to L-cysteine and the preliminary catalytic property of the Au nanoparticles on the inner surface of hollow poly(DVB-co-AA) microspheres were investigated.

  3. PREPARATION OF POLY(ETHYLENEGLYCOL-co-ACRYLIC ACID) MICROSPHERES WITH DIVINYLBENZNE AS CROSSLINKER BY DISTILLATION-PRECIPITATION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Zhao Dai; Xin-lin Yang; Wen-qiang Huang

    2007-01-01

    Monodisperse poly(poly(ethyleneglycol) methyl ether acrylate-co-acrylic acid) (poly(PEGMA-co-AA))microspheres were prepared by distillation-precipitation polymerization with divinylbenzene (DVB) as crosslinker with 2,2'-azobisisobutyronitrile (AIBN) as initiator in neat acetonitrile without stirring. Under various reaction conditions, four distinct morphologies including the sol, microemulsion, microgels and microspheres were formed during the distillation of the solvent from the reaction system. A 2D morphological map was established as a function of crosslinker concentration and the polar monomer AA concentration, in comonomer feed in the transition between the morphology domains. The effect of the covalent crosslinker DVB on the morphology of the polymer network was investigated in detail at AA fraction of 40 vol%.The ratios of acid to ethylene oxide units presenting in the comonomers dramatically affected the polymer-polymer interaction and hence the morphology of the resultant polymer network. The covalent crosslinking by DVB and the hydrogen bonding crosslinking between two acid units as well as between the acid and ethylene oxide unit played key roles in the formation of monodisperse polymer microspheres.

  4. Synthesis of hollow silver spheres using poly-(styrene-methyl acrylic acid) as templates in the presence of sodium polyacrylate

    Science.gov (United States)

    Wang, Aili; Yin, Hengbo; Ge, Chen; Ren, Min; Liu, Yumin; Jiang, Tingshun

    2010-02-01

    Hollow silver spheres were successfully prepared by reducing AgNO 3 with ascorbic acid and using negatively charged poly-(styrene-methyl acrylic acid) (PSA) spheres as templates in the presence of sodium polyacrylate as a stabilizer. Firstly, silver cations adsorbed on the surface of PSA spheres via electrostatic attraction between the carboxyl groups and silver cations were reduced in situ by ascorbic acid. The silver nanoparticles deposited on the surface of PSA spheres served as seeds for the further growth of silver shells. After that, extra amount of AgNO 3 and ascorbic acid solutions were added to form PSA/Ag composites with thick silver shells. In order to obtain compact silver shells, the as-prepared PSA/Ag composites were heated at 150 °C for 3 h. Then hollow silver spheres were prepared by dissolving PSA templates with tetrahydrofuran.

  5. Asymmetric Meerwein–Ponndorf–Verley reduction of long chain keto alkanoic acid methyl esters

    Directory of Open Access Journals (Sweden)

    AYE YUSUFOGLU

    2007-05-01

    Full Text Available 3-, 7- and 13-Monoketo tetradecanoic acid methyl esters carrying a ketogroup at the ends and at the middle of the chain with 14 carbon atoms were reduced by a Meerwein–Ponndorf–Verley reaction in the presence of R-(+-1,1'-binaphthalene-2,2'-diol, 1,2:5,6-D-di-O-isopropylidene-D-mannitol and L-(–-menthol. The highest enantiomeric purity of 65% ee was found for 13-hydroxy ester isomer. The enantiomeric excess was determined by 1H-NMR shift with Eu(tfc3 and by optical rotation.

  6. Origin of Kinetic Resolution of Hydroxy Esters through Catalytic Enantioselective Lactonization by Chiral Phosphoric Acids.

    Science.gov (United States)

    Changotra, Avtar; Sunoj, Raghavan B

    2016-08-05

    Kinetic resolution is a widely used strategy for separation and enrichment of enantiomers. Using density functional theory computations, the origin of how a chiral BINOL-phosphoric acid catalyzes the selective lactonization of one of the enantiomers of α-methyl γ-hydroxy ester is identified. In a stepwise mechanism, the stereocontrolling transition state for the addition of the hydroxyl group to the si face of the ester carbonyl in the case of the S isomer exhibits a network of more effective noncovalent interactions between the substrate and the chiral catalyst.

  7. Preparation and Reactions of Amino Acid Ester Sulfones as New Remote Asymmetrical Induced Reagents

    Institute of Scientific and Technical Information of China (English)

    ZHOU,Cheng-He; BAI,Xue; LI,Tan-Qing; WU,Jun; Alfred Hassner

    2004-01-01

    @@ The development of chiral auxiliary-controlled asymmetric synthesis has been receiving increasing interest in recent yearsfi,2] Various chiral auxiliary reagents have been observed[3] and a lot of results showed that variation of the chiral auxiliary could influence asymmetric induction. Recently, it has been reported the reaction of the aminated sulfones as a remote chiral auxiliary with α,β-unsaturated carbonyl compounds.[4] Here we would like to report the preparation of amino acid ester sulfones as new remote asymmetrical induced reagents and their reactions with α,β-unsaturated esters.

  8. Synthesis and transdermal properties of acetylsalicylic acid and selected esters

    OpenAIRE

    2006-01-01

    The primary aim of this study was to determine the transdermal penetration of acetylsalicylic acid and some of its derivatives, to establish a correlation, if any, with selected physicochemical properties and to determine if transdermal application of acetylsalicylic acid and its derivatives will give therapeutic drug concentrations with respect to transdermal flux. Ten derivatives of acetylsalicylic acid were prepared by esterification of acetylsalicyloyl chloride with ten different alcohols...

  9. Synthesis of oleic acid based esters as potential basestock for biolubricant production

    OpenAIRE

    Salih, Nadia; Salimon, Jumat; Yousif, Emad

    2011-01-01

    Ester derivatives of 9, 10-dihydroxystearic acid were prepared and characterized. The processes involved were epoxidation of oleic acid, opening of the oxirane ring, and esterification. The structures of the products were confirmed by FTIR, 1H- and 13C-NMR. The low-temperature properties of each product were characterized using the pour point test. Other physical properties, such as flash point and viscosity, were also determined. The results show that desirable low temperature pro...

  10. Characterization of interpenetrating networks of acrylic acid (AAc) and N-isopropylacrylamide (NIPAAm) synthesized by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Adem, E. [Departamento de Fisica Experimental, Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico DF 04510 (Mexico); Burillo, G. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico DF 04510 (Mexico)], E-mail: burillo@nucleares.unam.mx; Bucio, E. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico DF 04510 (Mexico); Magana, C. [Departamento de Fisica Experimental, Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico DF 04510 (Mexico); Avalos-Borja, M. [Centro de Nanociencias y Nanotecnologia, Universidad Nacional Autonoma de Mexico, A. Postal 2681, Ensenada, B.C. 22800 (Mexico)

    2009-07-15

    Interpenetrating networks of poly(acrylic acid) (PAAc) and poly(N-isopropylacrylamide) (PNIPAAm) were synthesized in two consecutive steps utilizing ionizing radiation in the first step and chemical reaction in the second step. The first network of PAAc hydrogel was formed by ionizing radiation (gamma or electron beam). The secondary gel of PNIPAAm was synthesized directly within the primary gel of PAAc from an aqueous solution of N-isopropylacrylamide (NIPAAm) containing a crosslinking agent, accelerator and redox initiator. The interpenetrating networks (IPNs) were characterized morphologically by scanning electron microscopy (SEM), and their thermal behavior was analyzed by differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA)

  11. Electrochemical synthesis of polyaniline/poly(2-acryl-amido-2-methyl-1-propane-sulfonic acid) composite

    Energy Technology Data Exchange (ETDEWEB)

    Lapkowski, M. (Inst. of Physical Chemistry and Technology of Polymers, Silesian Technical Univ., Gliwice (Poland))

    1993-03-22

    Conducting polyaniline/poly(2-acryl-amido-2-methyl-1-propane sulfonic acid) (PANi/PAMPS) composite films were synthesized electrochemically on platinum electrodes using a 10% aqueous PAMPS solution as the electrolyte. The electrochemical properties of the resulting polymer are similar to those observed for polyaniline doped with classical non-polymeric anions. PANi/PAMPS exhibits high cycling stability within the potential range of the first redox couple, but it undergoes degradation when the potential range characteristic of the second redox couple is reached. The degradation occurs independently of the electrolytic medium (HCl or 10% aqueous PAMPS). (orig.)

  12. IPN's of acrylic acid and N-isopropylacrylamide by gamma and electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Burillo, G. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, UNAM, Ciudad Universitaria, 04510 Mexico DF (Mexico)], E-mail: burillo@nucleares.unam.mx; Briones, M. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, UNAM, Ciudad Universitaria, 04510 Mexico DF (Mexico); Adem, E. [Instituto de Fisica UNAM, Apartado Postal 20-364, 01000 Mexico DF (Mexico)

    2007-12-15

    Interpenetrating networks (IPN) of temperature sensitive N-isopropylacrylamide (NIPAAm) and pH sensitive acrylic acid (AAc) monomer were prepared in two consecutive steps. Hydrogels of AAc were synthesized by gamma radiation from a {sup 60}Co gamma source and an electron beam from a Van de Graaff accelerator. A second hydrogel of NIPAAm was synthesized within the first AAc hydrogel by polymerization and cross-linking with a redox initiator and cross-linking agent. The thermal and pH sensitivity of the hydrogels were determined by measuring the swelling, and the morphology and composition by SEM.

  13. Preparation and characterization of acrylic acid-grafted poly (vinyl alcohol) hydrogel actuators using γ-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    An, Sung Jun; Lim, Youn Mook; Gwon, Hui Jeong; Kim, Yun Hye; Youn, Min Ho; Nho, Young Chang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Han, Dong Hyun; Kim, Chong Yeal [Dept. of Radiation Science AND Technology, Graduate School of Chonbuk National University, Jeonju (Korea, Republic of)

    2008-01-15

    Active polymer gels expand and contract in response to certain environmental stimuli, such as the application of an electric field or a change in the pH level of the surroundings. This ability to achieve large, reversible deformations with no external mechanical loading has generated much interest in the use of these gels as biomimetic actuators and artificial muscles. In this study, poly (vinyl alcohol)(PVA) grafted acrylic acid monomer (PVA-g-AAc) hydrogels were prepared by {sup 60}Co γ-ray irradiation and their properties such as degree of grafting and weight swelling in electrostimulation as an artificial muscle and actuator were investigated.

  14. Microfiltration membranes prepared from polyethersulfone powder grafted with acrylic acid by simultaneous irradiation and their pH dependence

    Science.gov (United States)

    Deng, Bo; Li, Jingye; Hou, Zhengchi; Yao, Side; Shi, Liuqing; Liang, Guoming; Sheng, Kanglong

    2008-07-01

    Polyethersulfone (PES) powder was grafted with acrylic acid (AAc) by simultaneous γ-ray irradiation. The kinetics of the radiation induced graft polymerization was studied and the grafted PES powder was characterized. Then, microfiltration (MF) membranes were prepared from PES-g-PAAc powder with different degrees of grafting (DG) under phase inversion method. The swelling behavior and the mean pore size of MF membranes were measured, and the filtration property was tested. The results showed that the pore size and the flux of MF membranes increased with the increase in DG. And, MF membranes' properties were dependent on the pH value.

  15. 超声提取-毛细管气相色谱法检测酱腌菜中对羟基苯甲酸酯%Determination of p-Hydroxy Benzoic Acid Ethyl Ester in Pickles by Ultrasonic Extracting-Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    张全美; 黄锦燕; 王守卿

    2012-01-01

    采用超声提取法提取酱腌菜中的对羟基苯甲酸甲酯、对羟基苯甲酸乙酯及对羟基苯甲酸丙酯,在SE30毛细管柱(33 m×0.53 mm,2.65 μm)上得到了良好分离.对羟基苯甲酸甲酯、对羟基苯甲酸乙酯及对羟基苯甲酸丙酯在0~750 μg/mL浓度范围内与色谱峰面积呈良好的线性关系,相关系数为0.9999.对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯的检出限分别为0.1,0.1,0.2 μg/mL,测定结果的相对标准偏差小于3.6%(n=11),平均回收率为84.5%~97.1%.%Ultrasonic extraction method was used to extract p-hydroxy benzoic acid methyl ester, ethyl ester and acrylic ester, which were separated in SE30 column(33 m×0.53 mm,2.65 μm). The content of p-hydroxy benzoic acid methyl ester, ethyl ester and acrylic ester had a linear relationship with the chromatographpeak area in the range of 0-750 μg / mL, and results correlation coefficient was 0.9999. The detection limits of p-hydroxy benzoic acid methyl ester, p-hydroxy benzoic acid ethyl ester and p-hydroxy benzoic acid acrylic ester were 0.1, 0.1,0.2 μg/mL, repectively, the RSD of determination results was less than 3.6%(n=ll). The average recoveries were 84.5%-97.1%.

  16. Tribological study of a highly hydrolytically stable phenylboronic acid ester containing benzothiazolyl in mineral oil

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhipeng [School of Chemistry and Chemical Engineering, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Shanghai Jiao Tong University, 200240 (China); Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Li, Xiufeng; Zhang, Yawen [School of Chemistry and Chemical Engineering, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Shanghai Jiao Tong University, 200240 (China); Ren, Tianhui, E-mail: thren@sjtu.edu.cn [School of Chemistry and Chemical Engineering, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Shanghai Jiao Tong University, 200240 (China); Zhao, Yidong [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039 (China); Zeng, Xiangqiong; Heide, E. van der [Laboratory for Surface Technology and Tribology, University of Twente, Drienerlolaan 5, 7522 NB Enschede (Netherlands)

    2014-07-01

    A novel long chain alkyl phenylboronic acid ester containing heterocyclic compound, bis (1-(benzothiazol-2-ylthio) propan-2-yl)-4-dodecylphenylboronic acid ester (DBBMT), was synthesized and characterized. The hydrolytic stability of the DBBMT was evaluated and the results show that DBBMT is of outstanding hydrolytic stability compared with normal borate esters, which indicates that the designed molecular structure, by introducing benzene ring to conjugate with the electron-deficient boron and the benzothiazole as a hinder group, is effective on obtaining a hydrolytically stable long chain alkyl phenylboronic acid ester. The tribological properties of DBBMT and ZDDP in mineral base oil were evaluated using a four-ball tribometer, which suggests that the DBBMT possesses comprehensive tribological properties and could be a potential candidate for the replacement of ZDDP. Furthermore, in order to understand the tribological behaviors, the worn surface was analyzed by X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES) spectroscopy. The results indicate that the elements S, B, O and Fe perform complicated tribochemical reactions to form the compact tribological film composed of B{sub 2}O{sub 3}, FeS, Fe{sub 3}O{sub 4} and FeSO{sub 4}.

  17. Synthesis and Primary Research on Antitumor Activity of Three New Panaxadiol Fatty Acid Esters

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    For making use of Ginseng resources that exhibit an antitumor activity and for finding new anticancer drugs,three new fatty acid ester compounds: 3β-acetoxy panaxadiol ( Ⅰ ), 3β-palmitic acid aceloxy panaxadiol ( Ⅱ ), and 3β-octadecanoic acid aceloxy panaxadiol( Ⅰ , Ⅱ , and Ⅲ ) were synthesized with panaxadiol, diacetyl oxide, palmityl chloride and stearyl chloride, and their structures were determined via MS, 13C NMR, IR, TLC, and so on. The molar yields of the three compounds are 75.14%, 79. 08%, and 72. 57%, respectively. Meanwhile, the antitumor activity of the three new panaxadiol fatty acid ester derivatives and panaxadiol was compared by using the method of MTT. Tumor cell used was Vero cell line. Positive control was 5-FU, blank was an RPMI1640 culture medium, negative control was an RPMI1640 culture medium and the solvent for drugs to be tested. Compound Ⅰ has the strongest antitumor activity followed by panaxadiol; compounds Ⅱ and Ⅲ have similar and weakest antitumor activities.Furthermore, the antitumor activities of the panaxadiol fatty acid ester derivatives show positive correlation with the concentration of the test group, but show no relationship with the molecular weight of fatty acid. The methods that are used to synthesize the three compounds with high yields and strong antitumor activities are simple and show a great potential for meeting the needs of industrial manufacture of these drugs.

  18. Fatty acid esters of 3-chloropropane-1,2-diol in edible oils.

    Science.gov (United States)

    Zelinková, Z; Svejkovská, B; Velísek, J; Dolezal, M

    2006-12-01

    A series of 25 virgin and refined edible oils, obtained from retailers, was analyzed for levels of free 3-chloropropane-1,2-diol (3-MCPD) and 3-MCPD released from esters with higher fatty acids (bound 3-MCPD). Oils containing free 3-MCPD ranging from 280 degrees C, and heating at 230 degrees C (260 degrees C) for up to 8 h, led to an increase in bound 3-MCPD levels. On the other hand, heating of olive oil resulted in a decrease in bound 3-MCPD levels. For comparison, fat isolated from salami was analyzed for intact fatty acid esters of 3-MCPD. This fat contained bound 3-MCPD at a level of 1670 microg kg-1 and the fatty acid esters of 3-MCPD mainly consisted of 3-MCPD diesters; monoesters of 3-MCPD were present in smaller amounts. The major types of 3-MCPD diesters (about 85%) were mixed diesters of palmitic acid with C18 fatty acids (stearic, oleic, linoleic acids). These diesters were followed by 3-MCPD distearate (11%) and 3-MCPD dipalmitate (4%). Generally, very little 3-MCPD existed as the free compound (31 microg kg-1).

  19. Synthesis of acylamino acid esters of nucleoside 5'-phosphates and their investigation with PMR and CD spectra.

    Science.gov (United States)

    Azhayev, A V; Popovkina, S V; Tarussova, N B; Kirpichnikov, M P; Florentiev, V L; Krayevsky, A A; Kukhanova, M K; Gottikh, B P

    1977-01-01

    The acylamino acid esters of nucleoside 5'-phosphates are synthesized via condensation of N-(N'-acylaminoacyl) imidazoles with nucleoside 5'-phosphates. The PMR and CD spectra of the esters obtained are studied. The 3'-isomers of the substances under study are observed to have a shift in the conformational N in equilibrium S equilibrium of the carbohydrate moiety in favour of the S-form as compared to the initial nucleosides and their 2'-acyl esters. PMID:909771

  20. Chemically Cross-Linked Poly(acrylic-co-vinylsulfonic Acid Hydrogel for the Delivery of Isosorbide Mononitrate

    Directory of Open Access Journals (Sweden)

    Talib Hussain

    2013-01-01

    Full Text Available We report synthesis, characterization, and drug release attributes of a series of novel pH-sensitive poly(acrylic-co-vinylsulfonic acid hydrogels. These hydrogels were prepared by employing free radical polymerization using ethylene glycol dimethacrylate (EGDMA and benzyl peroxide (BPO as cross-linker and initiator, respectively. Effect of acrylic acid (AA, polyvinylsulfonic acid (PVSA, and EGDMA on prepared hydrogels was investigated. All formulations showed higher swelling at high pHs and vice versa. Formulations containing higher content of AA and EGDMA show reduced swelling, but one with higher content of PVSA showed increased swelling. Hydrogel network was characterized by determining structural parameters and loaded with isosorbide mononitrate. FTIR confirmed absence of drug polymer interaction while DSC and TGA demonstrated molecular dispersion of drug in a thermally stable polymeric network. All the hydrogel formulations exhibited a pH dependent release of isosorbide mononitrate which was found to be directly proportional to pH of the medium and PVSA content and inversely proportional to the AA contents. Drug release data were fitted to various kinetics models. Results indicated that release of isosorbide mononitrate from poly(AA-co-VSA hydrogels was non-Fickian and that the mechanism was diffusion-controlled.

  1. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Science.gov (United States)

    2010-07-01

    ...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. (a) Chemical substance and significant new uses...-mino-al-kyl-car-bo-mon-o-cyc-lic ester, halogen acid salt (PMN P-88-1682) is subject to reporting...

  2. Poly(ethylene glycol)-co-methacrylamide-co-acrylic acid based nanogels for delivery of doxorubicin.

    Science.gov (United States)

    Kumar, Parveen; Behl, Gautam; Sikka, Manisha; Chhikara, Aruna; Chopra, Madhu

    2016-10-01

    Polymeric nanogels have been widely explored for their potential application as delivery carriers for cancer therapeutics. The ability of nanogels to encapsulate therapeutics by simple diffusion mechanism and the ease of their fabrication to impart target specificity in addition to their ability to get internalized into target cells make them good candidates for drug delivery. The present study aims to investigate the applicability of poly(ethylene glycol)-co-methacrylamide-co-acrylic acid (PMA)-based nanogels as a viable option for the delivery of doxorubicin (DOX). The nanogels were synthesized by free radical polymerization in an inverse mini-emulsion and characterized by nuclear magnetic resonance spectroscopy ((1)H NMR), Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy (TEM), X-ray diffraction and differential scanning calorimetry. DOX was physically incorporated into the nanogels (PMA-DOX) and the mechanism of its in vitro release was studied. TEM experiment revealed spherical morphology of nanogels and the hydrodynamic diameter of the neat nanogels was in the range of 160 ± 46.95 nm. The size of the nanogels increased from 235.1 ± 28.46 to 403.7 ± 89.89 nm with the increase in drug loading capacity from 4.68 ± 0.03 to 13.71 ± 0.01%. The sustained release of DOX was observed upto 80 h and the release rate decreased with increased loading capacity following anomalous release mechanism as indicated by the value of diffusion exponent (n = 0.64-0.75) obtained from Korsmeyer-Peppas equation. Further, cytotoxicity evaluation of PMA-DOX nanogels on HeLa cells resulted in relatively higher efficacy (IC50~5.88 μg/mL) as compared to free DOX (IC50~7.24 μg/mL) thus demonstrating that the preparation is potentially a promising drug delivery carrier.

  3. Toxicological assessment of 3-chloropropane-1,2-diol and glycidol fatty acid esters in food.

    Science.gov (United States)

    Bakhiya, Nadiya; Abraham, Klaus; Gürtler, Rainer; Appel, Klaus Erich; Lampen, Alfonso

    2011-04-01

    Fatty acid esters of 3-chloropropane-1,2-diol (3-MCPD) and glycidol are a newly identified class of food process contaminants. They are widespread in refined vegetable oils and fats and have been detected in vegetable fat-containing products, including infant formulas. There are no toxicological data available yet on the 3-MCPD and glycidol esters, and the primary toxicological concern is based on the potential release of 3-MCPD or glycidol from the parent esters by lipase-catalyzed hydrolysis in the gastrointestinal tract. Although 3-MCPD is assessed as a nongenotoxic carcinogen with a tolerable daily intake (TDI) of 2 μg/kg body weight (bw), glycidol is a known genotoxic carcinogen, which induces tumors in numerous organs of rodents. The initial exposure estimates, conducted by Federal Institute for Risk Assessment (BfR) under the assumption that 100% of the 3-MPCD and glycidol are released from their esters, revealed especially that infants being fed commercial infant formula could ingest harmful amounts of 3-MCPD and glycidol. However, the real oral bioavailability may be lower. As this gives rise for toxicological concern, the currently available toxicological data of 3-MCPD and glycidol and their esters are summarized in this review and discussed with regard to data gaps and further research needs.

  4. Kinematic viscosity of biodiesel components (fatty acid alkyl esters) and related compounds at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Gerhard Knothe; Kevin R. Steidley [US Department of Agriculture, Peoria, IL (United States). National Center for Agricultural Utilization Research

    2007-11-15

    Biodiesel, defined as the mono-alkyl esters of vegetable oils and animal fats is, has undergone rapid development and acceptance as an alternative diesel fuel. Kinematic viscosity is one of the fuel properties specified in biodiesel standards, with 40{sup o}C being the temperature at which this property is to be determined and ranges of acceptable kinematic viscosity given. While data on kinematic viscosity of biodiesel and related materials at higher temperatures are available in the literature, this work reports on the kinematic viscosity of biodiesel and a variety of fatty acid alkyl esters at temperatures from 40{sup o}C down to -10{sup o}C in increments of 5{sup o}C using the appropriately modified standard reference method ASTM D445. Investigating the low-temperature properties of biodiesel, including viscosity, of biodiesel and its components is important because of the problems associated with the use of biodiesel under these conditions. Such data may aid in developing biodiesel fuels optimized for fatty ester composition. An index termed here the low-temperature viscosity ratio (LTVR) using data at 0{sup o}C and 40{sup o}C (divide viscosity value at 0{sup o}C by viscosity value at 40{sup o}C) was used to evaluate individual compounds but also mixtures by their low-temperature viscosity behavior. Compounds tested included a variety of saturated, monounsaturated, diunsaturated and triunsaturated fatty esters, methyl ricinoleate, in which the OH group leads to a significant increase in viscosity as well as triolein, as well as some fatty alcohols and alkanes. Esters of oleic acid have the highest viscosity of all biodiesel components that are liquids at low temperatures. The behavior of blends of biodiesel and some fatty esters with a low-sulfur diesel fuel was also investigated. 28 refs., 3 figs., 10 tabs.

  5. Synthesis and transdermal properties of acetylsalicylic acid and selected esters.

    Science.gov (United States)

    Gerber, Minja; Breytenbach, Jaco C; Hadgraft, Jonathan; du Plessis, Jeanetta

    2006-03-01

    The primary aim of this study was to determine the transdermal penetration of acetylsalicylic acid and some of its derivatives, to establish a correlation, if any, with selected physicochemical properties and to determine if transdermal application of acetylsalicylic acid and its derivatives will give therapeutic drug concentrations with respect to transdermal flux. Ten derivatives of acetylsalicylic acid were prepared by esterification of acetylsalicyloyl chloride with ten different alcohols. The experimental aqueous solubility, logD and transdermal flux values were determined for acetylsalicylic acid and its derivatives at pH 4.5. In vitro penetration was measured through excised female human abdominal skin in diffusion cells. The experimental aqueous solubility of acetylsalicylic acid (6.56 mg/ml) was higher than that of the synthesised acetylsalicylate derivatives (ranging from 1.76 x 10(-3) to 3.32 mg/ml), and the logD of acetylsalicylic acid (-0.85) was lower than that of its derivatives (ranging from -0.25 to 1.95). There was thus an inverse correlation between the aqueous solubility data and the logD values. The experimental transdermal flux of acetylsalicylic acid (263.83 nmol/cm(2)h) was much higher than that of its derivatives (ranging from 0.12 to 136.02 nmol/cm(2)h).

  6. Enzymatic esterification of tapioca maltodextrin fatty acid ester.

    Science.gov (United States)

    Udomrati, Sunsanee; Gohtani, Shoichi

    2014-01-01

    In this work new types of hydrophobically modified maltodextrin were prepared by enzyme-catalyzed reaction of maltodextrin and three fatty acids: decanoic acid (C-10), lauric acid (C-12) and palmitic acid (C-16). Lipase obtained from Thermomyces lanuginosus was found to be a useful biocatalyst in the maltodextrin esterification. Esterified maltodextrin with a degree of substitution (DS) 0.015-0.084 was prepared at the optimum conditions of 60 °C for 4 h. The DS was found to be at its highest when maltodextrin and fatty acids were taken in the ratio 1:0.5. The functional properties of these esterified maltodextrin were investigated. All esterified maltodextrin did not completely dissolve in water. Esterified maltodextrin at a concentration of 25% (w/w) exhibited Newtonian flow behavior similar to that of native maltodextrin. Esterified maltodextrin had a higher viscosity compare to native maltodextrin. X-ray diffraction pattern of esterified maltodextrin indicated crystallization of the fatty acid side chains. The thermal stability of esterified maltodextrin was checked by differential scanning calorimetry (DSC). Esterified maltodextrin was then used as an emulsifier to make n-hexadecane O/W emulsions. The emulsions were characterized according to their oil droplet characteristics and emulsification index.

  7. Parallel Synthesis of an Imidazole-4,5-dicarboxamide Library Bearing Amino Acid Esters and Alkanamines

    Directory of Open Access Journals (Sweden)

    Rosanna Solinas

    2008-12-01

    Full Text Available The imidazole-4,5-dicarboxylic acid scaffold is readily derivatized with amino acid esters and alkanamines to afford compounds with intramolecularly hydrogen bonded conformations that mimic substituted purines and therefore are hypothesized to be potential inhibitors of kinases through competitive binding to the ATP site. In this work, a total of 126 dissymmetrically disubstituted imidazole-4,5-dicarboxamides with amino acid ester and alkanamide substituents were prepared by parallel synthesis. The library members were purified by column chromatography on silica gel and the purified compounds characterized by LC-MS with LC detection at 214 nm. A selection of the final compounds was also analyzed by 1H-NMR spectroscopy. The analytically pure final products have been submitted to the Molecular Library Small Molecule Repository (MLSMR for screening in the Molecular Library Screening Center Network (MLSCN as part of the NIH Roadmap.

  8. Synergistic extraction of praseodymium with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qian; WU Dong-bei; BAO Bo-rong

    2009-01-01

    The synergistic extraction of Pr3+ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507, HL) and 8-Hydroxyquinoline (HQ) in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr3+ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration on extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinolinc was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr3+.

  9. Gas chromatography-vacuum ultraviolet spectroscopy for analysis of fatty acid methyl esters.

    Science.gov (United States)

    Fan, Hui; Smuts, Jonathan; Bai, Ling; Walsh, Phillip; Armstrong, Daniel W; Schug, Kevin A

    2016-03-01

    A new vacuum ultraviolet (VUV) detector for gas chromatography was recently developed and applied to fatty acid methyl ester (FAME) analysis. VUV detection features full spectral acquisition in a wavelength range of 115-240nm, where virtually all chemical species absorb. VUV absorption spectra of 37 FAMEs, including saturated, monounsaturated, and polyunsaturated types were recorded. Unsaturated FAMEs show significantly different gas phase absorption profiles than saturated ones, and these classes can be easily distinguished with the VUV detector. Another advantage includes differentiating cis/trans-isomeric FAMEs (e.g. oleic acid methyl ester and linoleic acid methyl ester isomers) and the ability to use VUV data analysis software for deconvolution of co-eluting signals. As a universal detector, VUV also provides high specificity, sensitivity, and a fast data acquisition rate, making it a powerful tool for fatty acid screening when combined with gas chromatography. The fatty acid profile of several food oil samples (olive, canola, vegetable, corn, sunflower and peanut oils) were analyzed in this study to demonstrate applicability to real world samples.

  10. Solid Phase Synthesis of 2-Substituted 1,3-Oxazin-6-ones Using Resin-bound Cyclic Malonic Acid Ester

    Institute of Scientific and Technical Information of China (English)

    LIU, Zhan-Xiang(刘占祥); RUAN, Xiu-Xiu(阮秀秀); HUANG, Xian(黄宪)

    2004-01-01

    A facile solid phase synthesis of 2-substituted 1,3-oxazin-6-ones using polymer-supported Meldrum's acid has been reported. Reaction of the resin-bound cyclic malonic acid ester with triethyl orthoformate and subsequent double substitution with amide, afforded the corresponding polymer-supported acylaminomethylene cyclic malonic acid ester, which upon thermal treatment led to 1, 3-oxazin-6-ones in good yields and with high purity.

  11. Synthesis of allyl esters of fatty acids and their ovicidal effect on Cydia pomonella (L.).

    Science.gov (United States)

    Escribà, Marc; Barbut, Montserrat; Eras, Jordi; Canela, Ramon; Avilla, Jesús; Balcells, Mercè

    2009-06-10

    Eight allyl esters of fatty acids were synthesized in moderate to high yields with a novel two-step procedure using glycerol as a starting material. The two-step methodology avoids the use of allyl alcohol. The first step consisted of heating at 80 degrees C for 48 h a 2:1:5 mmol mixture of glycerol, a fatty acid, and chlorotrimethylsilane in a solvent-free medium. The crude compound was then dissolved in butanone and heated at 115 degrees C in the presence of NaI. A tandem Finkelstein rearrangement-elimination reaction occurs, producing the corresponding allyl ester. The activity of these esters against Cydia pomonella (L.) (Lepidoptera: Tortricidae) eggs was tested in the laboratory by topical application of one 0.1 microL drop. All of the compounds showed a concentration-mortality response and caused 100% mortality at the highest concentration tested (10 mg/mL). There was an inverse relationship between the alkyl chain length and the ovicidal activity of the allyl ester; the LC(50) and the LC(90) of the two compounds that have the longer alkyl chains were significantly higher than those of the rest of the compounds. The ovicidal and IGR activities of this kind of compound appear to be unprecedented.

  12. 40 CFR 721.990 - 1,4-Benzedicarboxylic acid, dimethyl ester, polymer with 1,4 - butanediol, cyclized.

    Science.gov (United States)

    2010-07-01

    ... ester, polymer with 1,4 - butanediol, cyclized. 721.990 Section 721.990 Protection of Environment..., dimethyl ester, polymer with 1,4 - butanediol, cyclized. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,4-benzedicarboxylic acid, dimethyl...

  13. Direct analysis of intact glycidyl fatty acid esters in edible oils using gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    van Steenbergen, H.; Hrnčiřík, K.; Ermacora, A.; de Koning, S.; Janssen, H.-G.

    2013-01-01

    Glycidyl esters (GE), fatty acid esters of glycidol, are process contaminants formed during edible oil processing. A novel direct method for the determination of intact GE in oils and fats based on gas chromatography-mass spectrometry (GC-MS) is presented. The method consists of a simple extraction

  14. Linear and cyclic ester Oligomers of succinic acid and 1,4-butanediol: Biocatalytic synthesis and characterization

    NARCIS (Netherlands)

    Habeych Narvaez, D.I.; Eggink, G.; Boeriu, C.G.

    2011-01-01

    The lipase-catalyzed synthesis of cyclic ester oligomers from non-activated succinic acid (A) and 1,4-butanediol (B) in the presence of immobilized Candida antarctica lipase B was investigated. Batch and pulse fed-batch systems were implemented to increase the formation of cyclic ester products. The

  15. Understanding field variation, quantum chemical modeling and molecular orbital analyses of trans-3-(trans-4-imidazolyl) acrylic acid

    Science.gov (United States)

    Gayathri, R.; Arivazhagan, M.

    2017-02-01

    In this work, a joint experimental (FTIR and FT-Raman) and theoretical (DFT and ab-initio) study on the structure and the vibrations of Trans-3-(trans-4-imidazolyl) acrylic acid (TTIAA) are compared and analyzed. The assignment of each normal mode has been made using the observed and calculated frequencies. The optimized geometries, harmonic vibrational wavenumbers and intensities of vibrational bands of trans-3-(trans-4-imidazolyl) acrylic acid (TTIAA) have been carried out using the HF/B3LYP method using the standard 6311++G(d,p) basis set calculations in this investigation. The result describes the variation in electrostatic and transport properties for zero and various external applied field. The variation in MPA charges are small due to the application of EFs: however, in most cases it is found to be systematic and almost uniform. When the field increases from 0.00 to 0.02 VÅ-1, the hybridization of molecular levels broadens the DOS and decreases the HLG from 3.6609 to 1.2325 eV; the decrease of band gap at the high field indicates that this molecule exhibit considerable electrical conductivity. Fukui indices to determine the local reactive site for the molecular systems during electrophilic, nucleophilic, radical and dual descriptor attacks. The results clearly show the superiority of MPA scheme. This study may be useful to design new molecules with more electrical conductivity.

  16. Preparation, characterization, and antibacterial activity studies of silver-loaded poly(styrene-co-acrylic acid) nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Song, Cunfeng [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Chang, Ying; Cheng, Ling; Xu, Yiting [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Chen, Xiaoling, E-mail: tinachen0628@163.com [Department of Endodontics, Xiamen Stomatology Hospital, Teaching Hospital of Fujian Medical University, Xiamen 361003 (China); Zhang, Long; Zhong, Lina [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Dai, Lizong, E-mail: lzdai@xmu.edu.cn [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China)

    2014-03-01

    A simple method for preparing a new type of stable antibacterial agent was presented. Monodisperse poly(styrene-co-acrylic acid) (PSA) nanospheres, serving as matrices, were synthesized via soap-free emulsion polymerization. Field-emission scanning electron microscopy micrographs indicated that PSA nanospheres have interesting surface microstructures and well-controlled particle size distributions. Silver-loaded poly(styrene-co-acrylic acid) (PSA/Ag-NPs) nanocomposites were prepared in situ through interfacial reduction of silver nitrate with sodium borohydride, and further characterized by transmission electron microscopy and X-ray diffraction. Their effects on antibacterial activity including inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bactericidal kinetics were evaluated. In the tests, PSA/Ag-NPs nanocomposites showed excellent antibacterial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. These nanocomposites are considered to have potential application in antibacterial coatings on biomedical devices to reduce nosocomial infection rates. - Highlights: • A new type of antibacterial agent (PSA/Ag-NPs nanocomposites) was synthesized. • The antibacterial activity against S. aureus and E. coli was studied. • Inhibition zone, MIC, MBC, and bactericidal kinetics were evaluated. • PSA/Ag-NPs nanocomposites showed excellent antibacterial activity.

  17. Improved Method for Preparation of Amidoxime Modified Poly(acrylonitrile-co-acrylic acid: Characterizations and Adsorption Case Study

    Directory of Open Access Journals (Sweden)

    Nur Amirah Mohd Zahri

    2015-07-01

    Full Text Available Redox polymerization of poly(acrylonitrile-co-acrylic acid (poly(AN-co-AA is performed at 40 °C under N2 gas by varying the ratio of acrylonitrile (AN and acrylic acid (AA in the feed. The yield production of poly(acrylonitrile (PAN is 73% and poly(AN-co-AA with a feed ratio of 93:7 is the highest yield (72%. The PAN and poly(AN-co-AA are further chemically modify with hydroxylamine hydrochloride. The FTIR spectroscopy is used to confirm the copolymerization of poly(AN-co-AA and chemical modification of poly(AN-co-AA. Elemental microanalysis shows that the overall trend percentage of carbon, hydrogen, and nitrogen for all feed ratios are slightly decreasing as the feed ratio of AA is increasing except for poly(AN-co-AA 93:7. The SEM images shows that spherical diameter of poly(AN-co-AA is smaller compared to the PAN and amidoxime (AO modified poly(AN-co-AA. The TGA (thermogravimetric analysis analysis reveals that the poly(AN-co-AA degrades at lower temperatures compared to the PAN but higher than AO modified poly(AN-co-AA. The case study adsorption test showed that the AO modified poly(AN-co-AA 93:7 had the highest percentage removal of Cd2+ and Pb2+.

  18. Preparation of acrylic acid-modified chitin improved by an experimental design and its application in absorbing toxic organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chao-Ming, E-mail: charming@mail.ksu.edu.tw [Department of Materials Engineering, Kun Shan University, Tainan, Taiwan (China); Chen, Lung-Chuan, E-mail: lcchen@mail.ksu.edu.tw [Department of Materials Engineering, Kun Shan University, Tainan, Taiwan (China); Yang, Hui-Chia, E-mail: yang.junkdna@gmail.com [Department of Environmental Engineering, Kun Shan University, Tainan, Taiwan (China); Li, Min-Hsing, E-mail: a1487561a@yahoo.com.tw [Department of Environmental Engineering, Kun Shan University, Tainan, Taiwan (China); Pan, Ting-Chung, E-mail: tcpan@mail.ksu.edu.tw [Department of Environmental Engineering, Kun Shan University, Tainan, Taiwan (China)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Acrylic acid-modified chitin. Black-Right-Pointing-Pointer Experimental design. Black-Right-Pointing-Pointer Graft copolymerization. Black-Right-Pointing-Pointer Adsorption of toxic organic compounds. Black-Right-Pointing-Pointer Very high adsorption capacity. - Abstract: Chitin grafted poly (acrylic acid) (chi-g-PAA) is synthesized and characterized as an adsorbent of toxic organic compounds. Chi-g-PAA copolymers are prepared using of ammonium cerium (IV) nitrate (Ce{sup 4+}) as the initiator. The highest grafting percentage of AA in chitin obtained using the traditional technique is 163.1%. A maximum grafting percentage of 230.6% is obtained using central composite design (CCD). Experimental results are consistent with theoretical calculations. The grafted copolymer is characterized by Fourier transform Infrared spectroscopy and solid state {sup 13}C NMR. A representative chi-g-AA copolymer is hydrolyzed to a type of sodium salt (chi-g-PANa) and used in the adsorption of malachite green (MG), methyl violet (MV), and paraquat (PQ) in aqueous. The monolayer adsorption capacities of these substances are 285.7, 357.1, and 322.6 mg/g-adsorbent, respectively. Thermodynamic calculations show that the adsorption of MG, MV, and PQ are more favored at diluted solutions. The high adsorption capacity of chi-g-PANa for toxic matter indicates its potential in the treatment of wastewater and emergency treatment of PQ-poisoned patients.

  19. Controlled release of diclofenac sodium from pH-responsive carrageenan-g-poly(acrylic acid) superabsorbent hydrogel

    Indian Academy of Sciences (India)

    Hossein Hosseinzadeh

    2010-07-01

    In this paper, controlled release of diclofenac sodium (DS) from pH-sensitive carrageenan-gpoly(acrylic acid) superabsorbent hydrogels was investigated. The hydrogels were prepared by graft copolymerization of acrylic acid (AA) onto kappa-carrageenan, using ammonium persulfate (APS) as a free radical initiator in the presence of methylene bisacrylamide (MBA) as a crosslinker. Infrared spectroscopy was carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy (SEM). The synthesized hydrogels were subjected to equilibrium swelling studies in simulated gastric and intestinal fluids (SGF and SIF). Hydrogels containing drug DS, at different drug-to-polymer ratios, were prepared by direct adsorption method. The loading yield was found to depend on both the impregnation time and the amount of encapsulated drug. In vitro drug-release studies in different buffer solutions showed that the most important parameter affecting the drug-release behaviour of hydrogels is the pH of the solution. The mechanism involved in release was Fickian ( ≤ 0.43, = 0.348) and Super Case II kinetics ( > 1, = 1.231) at pH 1.2 and 7.4, respectively.

  20. The Synthesis and Evaluation of Arctigenin Amino Acid Ester Derivatives.

    Science.gov (United States)

    Cai, En-Bo; Yang, Li-Min; Jia, Cai-Xia; Zhang, Wei-Yuan; Zhao, Yan; Li, Wei; Song, Xing-Zhuo; Zheng, Man-Ling

    2016-10-01

    The use of arctigenin (ARG), a traditional medicine with many pharmacological activities, has been restricted due to its poor solubility in water. Five amino acid derivatives of ARG have been synthesized using glycine, o-alanine, valine, leucine, and isoleucine, which have t-butyloxy carbonyl (BOC) as a protective group. In this study, we examined the effects of removing these protective groups. The results showed that the amino acid derivatives have better solubility and nitrite-clearing ability than ARG. Among the compounds tested, the amino acid derivatives without protective group were the best. Based on these results, ARG and its two amino acid derivatives without protective group (ARG8, ARG10) were selected to evaluate their anti-tumor activity in vivo at a dosage of 40 mg/kg. The results indicated that ARG8 and ARG10 both exhibit more anti-tumor activity than ARG in H22 tumor-bearing mice. The tumor inhibition rates of ARG8 and ARG10 were 69.27 and 43.58%, which was much higher than ARG. Furthermore, the mice treated with these compounds exhibited less damage to the liver, kidney and immune organs compared with the positive group. Furthermore, ARG8 and ARG10 improved the serum cytokine levels significantly compared to ARG. In brief, this study provides a method to improve the water solubility of drugs, and we also provide a reference basis for new drug development.

  1. Gas chromatographic separation of fatty acid esters of cholesterol and phytosterols on an ionic liquid capillary column.

    Science.gov (United States)

    Hammann, Simon; Vetter, Walter

    2015-12-15

    Steryl esters are high molecular weight compounds (600-700g/mol) regularly present as a minor lipid class in animal and plant lipids. Different sterol backbones (e.g., cholesterol, β-sitosterol and brassicasterol) which can be esterified with various fatty acids can result in highly complex steryl ester patterns in food samples. The gas chromatographic (GC) analysis of intact steryl esters is challenging, since high elution temperatures are required for their elution. On nonpolar GC phases, steryl esters with fatty acids with differing degree of unsaturation (e.g., oleate and linoleate) cannot be separated and there are only few polar columns available with sufficient temperature stability. In this study, we used gas chromatography with mass spectrometry (GC/MS) and analyzed intact steryl esters on a commercial room temperature ionic liquid (RTIL) column which was shortened to a length of 12m. The column separated the steryl esters both by total carbon number and by degree of unsaturation of the fatty acid. For instance, cholesteryl esters with stearic acid (18:0), oleic acid (18:1n-9), linoleic acid (18:2n-6) and α-linolenic acid (18:3n-3) could be resolved (R≥1.3) from each other. By analysis of synthesized standard substances, the elution orders for different steryl backbones and different fatty acids on a given sterol backbone could be determined. Analysis of spreads and plant oils allowed to determine retention times for 37 steryl esters, although a few co-elutions were observed. The ionic liquid column proved to be well-suited for the analysis of intact steryl esters.

  2. The stereodirecting effect of the glycosyl C5-carboxylate ester: stereoselective synthesis of beta-mannuronic acid alginates.

    Science.gov (United States)

    Codée, Jeroen D C; van den Bos, Leendert J; de Jong, Ana-Rae; Dinkelaar, Jasper; Lodder, Gerrit; Overkleeft, Herman S; van der Marel, Gijsbert A

    2009-01-02

    Glycosylations of mannuronate ester donors proceed highly selectively to produce the 1,2-cis-linked products. We here forward a mechanistic rationale for this counterintuitive selectivity, based on the remote stereodirecting effect of the C5-carboxylate ester, which has been demonstrated using pyranosyl uronate ester devoid of ring substituents other than the C5- carboxylate ester. It is postulated that the C5-carboxylate ester prefers to occupy an axial position in the oxacarbenium intermediate, thereby favoring the formation of the (3)H4 half-chair over the (4)H3 conformer. Nucleophilic attack on the (3)H4 half-chair intermediate occurs in a beta-fashion, providing the 1,2-cis-mannuronates with excellent stereoselectivity. The potential of the mannuronate ester donors in the formation of the beta-mannosidic linkage has been capitalized upon in the construction of a mannuronic acid alginate pentamer using a convergent orthogonal glycosylation strategy.

  3. Unambiguous detection of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana).

    Science.gov (United States)

    Grynbaum, Marc David; Hentschel, Petra; Putzbach, Karsten; Rehbein, Jens; Krucker, Manfred; Nicholson, Graeme; Albert, Klaus

    2005-09-01

    HPLC atmospheric pressure chemical ionization (APCI)/MS, GC MS, HPLC diode array detection (DAD), and NMR were used for the identification of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana). Matrix solid phase dispersion was applied for the extraction of the carotenoids. This gentle and expeditious extraction technique for solid and viscous samples leads to distinct higher enrichment rates than the conventional liquid-liquid extraction. The chromatographic separation was achieved employing a C30 RP column that allows the separation of shape-constrained geometrical isomers. A methanol/tert-butylmethyl ether/water gradient was applied. (all-E) Astaxanthin and the geometrical isomers were identified by HPLC APCI/MS, by coelution with isomerized authentical standard, by UV spectroscopy (DAD), and three isomers were unambiguously assigned by microcoil NMR spectroscopy. In this method, microcoils are transversally aligned to the magnetic field and have an increased sensitivity compared to the conventional double-saddle Helmholtz coils, thus enabling the measurement on small samples. The carotenol fatty acid esters were saponified enzymatically with Lipase type VII from Candida rugosa. The fatty acids were detected by GC MS after transesterification, but also without previous derivatization by HPLC APCI/MS. C14:0, C16:0, C16:1, C18:1, C20:0, C20:5, and C22:6 were found in astaxanthin monoesters and in astaxanthin diesters. (all-E) Astaxanthin was identified as the main isomer in six fatty acid ester fractions by NMR. Quantitation was carried out by the method of internal standard. (13-cis) Astaxanthin (70 microg/g), 542 microg/g (all-E) astaxanthin, 36 microg/g unidentified astaxanthin isomer, 62 microg/g (9-cis) astaxanthin, and 7842 microg/g astaxanthin fatty acid esters were found.

  4. Antifungal properties of alpha,omega-alkanedicarboxylic acids and their dimethyl esters.

    Science.gov (United States)

    Gershon, H; Shanks, L

    1976-08-01

    Thirteen alpha, omega-alkanedicarboxylic acids (C2-C12, C14, and C16) and their dimethyl esters were tested against Aspergillus niger, Trichoderma viride, and Myrothecium verrucaria in Sabourauc dextrose agar at pH 4.0 AND 5.6. Toxicity to Canadida albicans, Trichophyton mentagrophytes, and Mucor mucedo was determined in the same medium at pH 5.6 and 7.0 in the absence and presence of 10% beef serum. The dicarboxylic acids possessed very poor to no antifungal activity against all six fungi. The fungitoxicity of the dimethyl esters to A. niger, T. viride, and M. verrucaria was C8 = C9 greater than C7 greater than C6 = C5 greater than C10 greater than C4 greater than C11 and to C. albicans, T. mentagrophytes, and M. mucedo C9 greater than C10 greater than C11 greater than C12 = C8 greater than C7 greater than C6 greater than C5 greater than C4 greater than C3. The fungitoxicity of the esters of fatty acids and alpha-omega-alkanedicarboxylic acids was influenced by chain length and not by the pH of the medium or the absence or presence of beef serum.

  5. NaY zeolites modified by La~(3+) and Ba~(2+): the effect of synthesis details on surface structure and catalytic performance for lactic acid to acrylic acid

    Institute of Scientific and Technical Information of China (English)

    闫婕; 余定华; 李恒; 孙鹏; 黄和

    2010-01-01

    Modified NaY zeolites have been widely studied and the modification metal element is normally single, while few researches have been conducted on NaY zeolites modified by two kinds of metals. In our study, a series of La3+ and Ba2+ modified NaY zeolites were synthesized through different impregnation procedures. Lactic acid dehydration to acrylic acid was selected as a probe reaction to test the catalytic performance of these zeolites synthesized. The effects of synthesis details on their pore structures an...

  6. Physicochemical properties of poly(lactic acid-co-glycolic acid film modified via blending with poly(butyl acrylate-co-methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Guoquan Zhu

    2013-01-01

    Full Text Available A series of poly(lactic acid-co-glycolic acid (PLGA/poly(butyl acrylate-co-methyl methacrylate (P(BA-co-MMA blend films with different P(BA-co-MMA mole contents were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLGAP(BA-co-MMA blend films were studied by scanning electron microscopy (SEM. Thermal, mechanical, and chemical properties of PLGAP(BA-co-MMA blend films were investigated by differential scanning calorimeter (DSC, thermogravimetric analysis (TGA, tensile tests, and surface contact angle tests. The introduction of P(BA-co-MMA could modify the properties of PLGA films.

  7. Fatty acid esters of phloridzin induce apoptosis of human liver cancer cells through altered gene expression.

    Directory of Open Access Journals (Sweden)

    Sandhya V G Nair

    Full Text Available Phloridzin (phlorizin or phloretin 2'-O-glucoside is known for blocking intestinal glucose absorption. We have investigated the anticarcinogenic effect of phloridzin and its novel derivatives using human cancer cell lines. We have synthesised novel acylated derivatives of phloridzin with six different long chain fatty acids by regioselective enzymatic acylation using Candida Antarctica lipase B. The antiproliferative effects of the new compounds were investigated in comparison with the parent compounds, phloridzin, aglycone phloretin, the six free fatty acids and chemotherapeutic drugs (sorafenib, doxorubicin and daunorubicin using human hepatocellular carcinoma HepG2 cells, human breast adenocarcinoma MDA-MB-231 cells and acute monocytic leukemia THP-1 cells along with normal human and rat hepatocytes. The fatty acid esters of phloridzin inhibited significantly the growth of the two carcinoma and leukemia cells while similar treatment doses were not toxic to normal human or rat hepatocytes. The antiproliferative potency of fatty esters of phloridzin was comparable to the potency of the chemotherapeutic drugs. The fatty acid esters of phloridzin inhibited DNA topoisomerases IIα activity that might induce G0/G1 phase arrest, induced apoptosis via activation of caspase-3, and decreased ATP level and mitochondrial membrane potential in HepG2 cells. Based on the high selectivity on cancer cells, decosahexaenoic acid (DHA ester of phloridzin was selected for gene expression analysis using RT2PCR human cancer drug target array. Antiproliferative effect of DHA ester of phloridzin could be related to the down regulation of anti-apoptotic gene (BCL2, growth factor receptors (EBFR family, IGF1R/IGF2, PDGFR and its downstream signalling partners (PI3k/AKT/mTOR, Ras/Raf/MAPK, cell cycle machinery (CDKs, TERT, TOP2A, TOP2B as well as epigenetics regulators (HDACs. These results suggest that fatty esters of phloridzin have potential chemotherapeutic effects

  8. Biochemical mechanism of Caffeic Acid Phenylethyl Ester (CAPE) selective toxicity towards melanoma cell lines

    OpenAIRE

    Kudugunti, Shashi K.; Vad, Nikhil M.; Whiteside, Amanda J.; Naik, Bhakti U.; Yusuf, Mohd. A.; Srivenugopal, Kalkunte S.; Moridani, Majid Y.

    2010-01-01

    In the current work, we investigated the in-vitro biochemical mechanism of caffeic acid phenylethyl ester (CAPE) toxicity and eight hydroxycinnamic/caffeic acid derivatives in-vitro, using tyrosinase enzyme as a molecular target in human SK-MEL-28 melanoma cells. Enzymatic reaction models using tyrosinase/O2 and HRP/H2O2 were used to delineate the role of one- and two-electron oxidation. Ascorbic acid (AA), NADH and GSH depletion were used as markers of quinone formation and oxidative stress ...

  9. Isoquercitrin Esters with Mono- or Dicarboxylic Acids: Enzymatic Preparation and Properties.

    Science.gov (United States)

    Vavříková, Eva; Langschwager, Fanny; Jezova-Kalachova, Lubica; Křenková, Alena; Mikulová, Barbora; Kuzma, Marek; Křen, Vladimír; Valentová, Kateřina

    2016-06-07

    A series of isoquercitrin (quercetin-3-O-β-d-glucopyranoside) esters with mono- or dicarboxylic acids was designed to modulate hydro- and lipophilicity and biological properties. Esterification of isoquercitrin was accomplished by direct chemoenzymatic reaction using Novozym 435 (lipase from Candida antarctica), which accepted C₅- to C12-dicarboxylic acids; the shorter ones, such as oxalic (C₂), malonic (C₃), succinic (C₄) and maleic (C₄) acids were not substrates of the lipase. Lipophilicity of monocarboxylic acid derivatives, measured as log P, increased with the chain length. Esters with glutaric and adipic acids exhibited hydrophilicity, and the dodecanedioic acid hemiester was more lipophilic. All derivatives were less able to reduce Folin-Ciocalteau reagent (FCR) and scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) than isoquercitrin; ABTS (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) radical-scavenging activity was comparable. Dodecanoate and palmitate were the least active in FCR and ABTS scavenging; dodecanoate and hemiglutarate were the strongest DPPH scavengers. In contrast, most derivatives were much better inhibitors of microsomal lipoperoxidation than isoquercitrin; butyrate and hexanoate were the most efficient. Anti-lipoperoxidant activity of monocarboxylic derivatives, except acetates, decreased with increasing aliphatic chain. The opposite trend was noted for dicarboxylic acid hemiesters, isoquercitrin hemidodecanedioate being the most active. Overall, IQ butyrate, hexanoate and hemidodecanedioate are the most promising candidates for further studies.

  10. Isoquercitrin Esters with Mono- or Dicarboxylic Acids: Enzymatic Preparation and Properties

    Directory of Open Access Journals (Sweden)

    Eva Vavříková

    2016-06-01

    Full Text Available A series of isoquercitrin (quercetin-3-O-β-d-glucopyranoside esters with mono- or dicarboxylic acids was designed to modulate hydro- and lipophilicity and biological properties. Esterification of isoquercitrin was accomplished by direct chemoenzymatic reaction using Novozym 435 (lipase from Candida antarctica, which accepted C5- to C12-dicarboxylic acids; the shorter ones, such as oxalic (C2, malonic (C3, succinic (C4 and maleic (C4 acids were not substrates of the lipase. Lipophilicity of monocarboxylic acid derivatives, measured as log P, increased with the chain length. Esters with glutaric and adipic acids exhibited hydrophilicity, and the dodecanedioic acid hemiester was more lipophilic. All derivatives were less able to reduce Folin–Ciocalteau reagent (FCR and scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl than isoquercitrin; ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid radical-scavenging activity was comparable. Dodecanoate and palmitate were the least active in FCR and ABTS scavenging; dodecanoate and hemiglutarate were the strongest DPPH scavengers. In contrast, most derivatives were much better inhibitors of microsomal lipoperoxidation than isoquercitrin; butyrate and hexanoate were the most efficient. Anti-lipoperoxidant activity of monocarboxylic derivatives, except acetates, decreased with increasing aliphatic chain. The opposite trend was noted for dicarboxylic acid hemiesters, isoquercitrin hemidodecanedioate being the most active. Overall, IQ butyrate, hexanoate and hemidodecanedioate are the most promising candidates for further studies.

  11. Heating Two Types of Enriched Margarine: Complementary Analysis of Phytosteryl/Phytostanyl Fatty Acid Esters and Phytosterol/Phytostanol Oxidation Products.

    Science.gov (United States)

    Scholz, Birgit; Menzel, Nicole; Lander, Vera; Engel, Karl-Heinz

    2016-04-06

    Two phytosteryl and/or phytostanyl fatty acid ester-enriched margarines were subjected to common heating procedures. UHPLC-APCI-MS analysis resulted for the first time in comprehensive quantitative data on the decreases of individual phytosteryl/-stanyl fatty acid esters upon heating of enriched foods. These data were complemented by determining the concurrently formed phytosterol/-stanol oxidation products (POPs) via online LC-GC. Microwave-heating led to the least decreases of esters of approximately 5% in both margarines. Oven-heating of the margarine in a casserole caused the greatest decreases, with 68 and 86% esters remaining, respectively; the impact on individual esters was more pronounced with increasing degree of unsaturation of the esterified fatty acids. In the phytosteryl/-stanyl ester-enriched margarine, approximately 20% of the ester losses could be explained by the formation of POPs; in the phytostanyl ester-enriched margarine, the POPs accounted for <1% of the observed ester decreases.

  12. The CGC enantiomer separation of 2-arylcarboxylic acid esters by using β-cyclodextrin derivatives as chiral stationary phases.

    Science.gov (United States)

    Shi, Xueyan; Liu, Feipeng; Mao, Jianyou

    2016-03-17

    Chiral 2-arylcarboxylic acid esters are important intermediates in preparation of enantioenriched 2-arylpropionic acids type Non-steroidal anti-inflammatory drugs (NSAIDs). Enantiomer separation of 2-arylcarboxylic acid esters is crucial for evaluation of the asymmetric synthesis efficiency and the enantiomer excess of chiral 2-arylcarboxylic acid derivatives. The capillary gas chromatography (CGC) enantiomer separation of 17 pairs of 2-arylcarboxylic acid esters enantiomers was conducted by using seven different β-cyclodextrin derivatives (CDs) as chiral stationary phases. It was found that for the 7 pairs of 2-phenylpropionates enantiomers, CDs with both alkyl and acyl substituents especially 2,6-di-O-pentyl-3-O-butyryl-β-cyclodextrin exhibited better enantiomer separation abilities than the other CDs examined. For the 7 pairs of 2-(4-substituted phenyl)propionates enantiomers, 2,3,6-tri-O-methyl-β-cyclodextrin possessed better enantiomer separation abilities than the other CDs. Among the 3 pairs of 2-phenylbutyrates enantiomers examined, only methyl 2-phenylbutyrate enantiomers could be separated by three CDs among the 7 CDs tested, while enantiomers of ethyl 2-phenylbutyrate and isopropyl 2-phenylbutyrate couldn't be separated by any of the 7 CDs tested. Besides the structures of CDs, the structures of 2-arylcarboxylic acid esters including different ester moieties, substituents of phenyl, and different carboxylic acids moieties in 2-arylcarboxylic acid esters also affected the enantiomer separation results greatly. The CGC enantiomer separation results of 2-arylcarboxylic acid esters on different CDs are useful for solving the enantiomer separation problem of 2-arylcarboxylic acid esters.

  13. Coriander seed oil methyl esters as biodiesel fuel: Unique fatty acid composition and excellent oxidative stability

    Energy Technology Data Exchange (ETDEWEB)

    Moser, Bryan R.; Vaughn, Steven F. [United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N. University St, Peoria, IL 61604 (United States)

    2010-04-15

    Coriander (Coriandrum sativum L.) seed oil methyl esters were prepared and evaluated as an alternative biodiesel fuel and contained an unusual fatty acid hitherto unreported as the principle component in biodiesel fuels: petroselinic (6Z-octadecenoic; 68.5 wt%) acid. Most of the remaining fatty acid profile consisted of common 18 carbon constituents such as linoleic (9Z,12Z-octadeca-dienoic; 13.0 wt%), oleic (9Z-octadecenoic; 7.6 wt%) and stearic (octadecanoic; 3.1 wt%) acids. A standard transesterification procedure with methanol and sodium methoxide catalyst was used to provide C. sativum oil methyl esters (CSME). Acid-catalyzed pretreatment was necessary beforehand to reduce the acid value of the oil from 2.66 to 0.47 mg g{sup -1}. The derived cetane number, kinematic viscosity, and oxidative stability (Rancimat method) of CSME was 53.3, 4.21 mm{sup 2} s{sup -1} (40 C), and 14.6 h (110 C). The cold filter plugging and pour points were -15 C and -19 C, respectively. Other properties such as acid value, free and total glycerol content, iodine value, as well as sulfur and phosphorous contents were acceptable according to the biodiesel standards ASTM D6751 and EN 14214. Also reported are lubricity, heat of combustion, and Gardner color, along with a comparison of CSME to soybean oil methyl esters (SME). CSME exhibited higher oxidative stability, superior low temperature properties, and lower iodine value than SME. In summary, CSME has excellent fuel properties as a result of its unique fatty acid composition. (author)

  14. Calculations of phase equilibria for mixtures of triglycerides, fatty acids, and their esters in lower alcohols

    Science.gov (United States)

    Stepanov, D. A.; Ermakova, A.; Anikeev, V. I.

    2011-01-01

    The objects of study were mixtures containing triglycerides and lower alcohols and also the products of the transesterification of triglycerides, glycerol and fatty acid esters. The Redlich-Kwong-Soave equation of state was used as a thermodynamic model for the phase state of the selected mixtures over wide temperature, pressure, and composition ranges. Group methods were applied to determine the critical parameters of pure substances and their acentric factors. The parameters obtained were used to calculate the phase diagrams and critical parameters of mixtures containing triglycerides and lower alcohols and the products of the transesterification of triglycerides, glycerol and fatty acid esters, at various alcohol/oil ratios. The conditions of triglyceride transesterification in various lower alcohols providing the supercritical state of reaction mixtures were selected.

  15. Possible molecular targets for therapeutic applications of caffeic acid phenethyl ester in inflammation and cancer

    Directory of Open Access Journals (Sweden)

    Ghulam Murtaza

    2015-03-01

    Full Text Available Of the various derivatives of caffeic acid, caffeic acid phenethyl ester (CAPE is a hydrophobic, bioactive polyphenolic ester obtained from propolis extract. The objective in writing this review article was to summarize all published studies on therapeutics of CAPE in inflammation and cancer to extract direction for future research. The possible molecular targets for the action of CAPE, include various transcription factors such as nuclear factor-κB, tissue necrosis factor-α, interleukin-6, cyclooxygenase-2, Nrf2, inducible nitric oxide synthase, nuclear factor of activated T cells, hypoxia-inducible factor-1α, and signal transducers and activators of transcription. Based on the valuable data on its therapeutics in inflammation and cancer, clinical studies of CAPE should also be conducted to explore its toxicities, if any.

  16. Measurement uncertainty of ester number, acid number and patchouli alcohol of patchouli oil produced in Yogyakarta

    Science.gov (United States)

    Istiningrum, Reni Banowati; Saepuloh, Azis; Jannah, Wirdatul; Aji, Didit Waskito

    2017-03-01

    Yogyakarta is one of patchouli oil distillation center in Indonesia. The quality of patchouli oil greatly affect its market price. Therefore, testing quality of patchouli oil parameters is an important concern, one through determination of the measurement uncertainty. This study will determine the measurement uncertainty of ester number, acid number and content of patchouli alcohol through a bottom up approach. Source contributor to measurement uncertainty of ester number is a mass of the sample, a blank and sample titration volume, the molar mass of KOH, HCl normality, and replication. While the source contributor of the measurement uncertainty of acid number is the mass of the sample, the sample titration volume, the relative mass and normality of KOH, and repetition. Determination of patchouli alcohol by Gas Chromatography considers the sources of measurement uncertainty only from repeatability because reference materials are not available.

  17. Effect of time and temperature exposition in the crystallinity degree of sulfonated poly-(styrene acrylic acid) (PSAA-S)

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, G.W.; Becker, E.B.; Silva, L.; Naspolini, A.M.; Consenso, E.C.; Paula, M.M.S.; Fiori, M.A., E-mail: glau_bn@hotmail.co [University of Extreme South of Santa Catarina Criciuma, SC (Brazil). Dept. of Materials Engineering; Silveira, F.Z. [Federal University of Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. of Chemical Engineering

    2010-07-01

    Polymers with special properties have been increasingly applied in the development of technological devices. For example, polymeric materials with special electric properties, such as sulfonated poly-(styrene-acrylic acid) - PSAA-S, are of great interest for showing different conductivities depending on the environment where they are applied. The special properties of PSAA are obtained only after sulfonation step in acidic media. The present work aimed to evaluate the effect of time and temperature exposition in the crystallinity degree of PSAA-S, through a statistical experimental factorial planning. The samples of PSAA-S were submitted to FT-IR and DRX tests. The results showed that the temperature and the time of exposition are significant factors in the crystallinity degree of PSAA-S, considering that the crystal lattices created during the polymerization are damaged by the action of time and temperature at which the polymer is exposed. (author)

  18. Characterization of pH-sensitive Poly (acrylic acid-co-N-vinyl-2-pyrrolidone) Hydrogels Prepared by Gamma Radiation

    Institute of Scientific and Technical Information of China (English)

    YANG Ming-cheng; HE Su-qin; LIU Wen-tao; SONG Hong-yan; ZHU Cheng-shen

    2007-01-01

    The pH-sensitive copolymer hydrogels were prepared with the monomers of acrylic acid and N-vinyl-2-pyrrolidone based on gamma radiation technique. The morphology of the hydrogels was monitored by using scanning electron microscope. The influence of absorbed dose, monomer compasition and concentration on the swelling ratio (SR) of the hydrogels were investigated in detail. The effect of pH and temperature of the swelling medium on the swelling behavior of the hydrogels were also examined. The results show that the SR of the copolymer hydrogels decreases with the monomer concentration and absorbed dose increasing. The copolymer hydrogels show a better pH-sensitive behavior. In alkaline solution, the SR of the hydrogels is much higher than in acid solution.

  19. Improvement of foaming properties of cuttlefish skin gelatin by modification with N-hydroxysuccinimide esters of fatty acid

    NARCIS (Netherlands)

    Aewsiri, T.; Benjakul, S.; Visessanguan, W.; Wierenga, P.A.; Gruppen, H.

    2011-01-01

    Conformation and foaming properties of cuttlefish skin gelatin modified by N-hydroxysuccinimide esters of different saturated fatty acids including capric acid (C10:0), lauric acid (C12:0) and myristic acid (C14:0) at different molar ratios (0.25, 0.50, 1.00 and 2.00) were investigated. Covalent att

  20. Hydroxycinnamic acids are ester-linked directly to glucosyl moieties within the lignan macromolecule from flaxseed hulls

    NARCIS (Netherlands)

    Struijs, K.; Vincken, J.P.; Verhoef, R.P.; Voragen, A.G.J.; Gruppen, H.

    2008-01-01

    In flaxseed hulls, lignans are present in an oligomeric structure. Secoisolariciresinol diglucoside (SDG), ester-linked to hydroxy-methyl-glutaric acid (HMGA), forms the backbone of this lignan macromolecule. The hydroxycinnamic acids p-coumaric acid glucoside (CouAG) and ferulic acid glucoside (FeA

  1. Characterization of Lipids and Fatty Acid Methyl Ester Contents in Leaves and Roots of Crocus vallicola

    OpenAIRE

    YAYLI, Nurettin; KIRAN, Zerrin; SEYMEN, Hasan; GENÇ, Hasan

    2001-01-01

    The chemical composition of the fatty acids methyl esters (FAMEs) and other lipids in leaves and roots of Crocusvallicola were analyzed by gas chromatography-mass spectrometry(GC-MS). In this work, twenty-eight compounds, including 22 FAMEs, 1 aldehyde, 3 hydrocarbons (substitute alkane and alkene), 2 alcohols in the leaves and twenty-one compounds (17 FAMEs, 1 anhydride, 1 substitute alcohol, 1 ketone, 1 substitute amide) in the roots were identified by GC-MS from C. vallicola. Th...

  2. [Determination of phthalic acid esters in textiles by solid phase extraction-gas chromatography].

    Science.gov (United States)

    Niu, Zengyuan; Ye, Xiwen; Fang, Liping; Xue, Qiuhong; Sun, Zhongsong

    2006-09-01

    A method was established for the simultaneous determination of some phthalic acid esters, namely, dimethyl phthalate (DMP), diethyl phthalate (DEP), dipropyl phthalate (DPrP), dibutyl phthalate (DBP), diamyl phthalate (DAP), dihexyl phthalate (DHP), benzyln-butyl phthalate (BBP), di-(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP), di-n-octyl phthalate (DNOP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP) in textiles by solid phase extraction (SPE) coupled with gas chromatography (GC). The phthalic acid esters in textiles were extracted by Soxhlet extraction with hexane, the extracts were then cleaned up and enriched by a strong anion exchange (SAX) SPE cartridge. The parameters affecting the purification efficiency of SPE cartridge, such as solvent conditioning, rinsing, and elution, were studied. Conditioning with 5 mL hexane and rinsing with 3 mL isooctane were proved to be the optimal conditions. Of the several solvent ratios (ethylacetate in hexane) used for selective elution of phthalic acid esters from the SAX SPE cartridge, the 15% (v/v) content for ethylacetate in hexane gave the best result. Under the optimized conditions, the recoveries of phthalic acid esters for spiked standards (n=7) were 86.3%-102.7%, and the relative standard deviations (RSDs) were less than 5%. In this method the detection limits for DMP, DEP, DPrP, DBP, DAP, BBP, DCHP, DEHP, DNOP were all below 1 mg/kg, and the detection limits for DINP and DIDP were 1.74 mg/kg and 1.55 mg/kg respectively. This SPE-GC method is sensitive, accurate and suitable for the analysis of phthalate environmental hormones in textiles.

  3. Preferential cytotoxicity on tumor cells by caffeic acid phenethyl ester isolated from propolis.

    Science.gov (United States)

    Grunberger, D; Banerjee, R; Eisinger, K; Oltz, E M; Efros, L; Caldwell, M; Estevez, V; Nakanishi, K

    1988-03-15

    The honeybee hive product, propolis, is a folk medicine employed for treating various ailments. Many important pharmaceutical properties have been ascribed to propolis, including anti-inflammatory, antiviral, immunostimulatory and carcinostatic activities. Propolis extracts have provided an active component identified as caffeic acid phenethyl ester (CAPE), which was readily prepared in one step. Differential cytotoxicity has been observed in normal rat/human versus transformed rat/human melanoma and breast carcinoma cell lines in the presence of CAPE.

  4. Synthesis and Properties of Lactic Acid-based Cross-linked Poly(ester-amide)

    Institute of Scientific and Technical Information of China (English)

    Yue Ying HE; Cong Ming XIAO

    2006-01-01

    A novel lactic acid-based cross-linked poly(ester-amide) (LCPEA) was synthesized. The gel fraction of the LCPEA could be modulated by the reaction conditions and it affected the mechanical and thermal properties of the LCPEA. The tensile strength, elastic modulus and bend strength of the LCPEA of 65% gel fraction were 4.65, 136.55 and 39.63 MPa, respectively. The thermal decomposition temperature (50 wt%) of the LCPEA was around 410 ℃.

  5. Hydrolytic activity of -alkoxide/acetato-bridged binuclear Cu(II) complexes towards carboxylic acid ester

    Indian Academy of Sciences (India)

    Weidong Jiang; Bin Xu; Zhen Xiang; Shengtian Huang; Fuan Liu; Ying Wang

    2013-09-01

    Two -alkoxide/acetate-bridged small molecule binuclear copper(II) complexes were synthesized, and used to promote the hydrolysis of a classic carboxylic acid ester, -nitrophenyl picolinate (PNPP). Both binuclear complexes exhibited good hydrolytic reactivity, giving rise to . 15547- and 17462-fold acceleration over background value for PNPP hydrolysis at neutral conditions, respectively. For comparing, activities of the other two mononuclear analogues were evaluated, revealing that binuclear complexes show approximately 150- and 171-fold kinetic advantage over their mononuclear analogues.

  6. Syntheses of Macrocyclic Amides from L-Amino Acid Esters by RCM

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A series of succinate-derived macrocyclic amides( 1 ) was synthesized via ring-closing metathesis (RCM) as the key step. The substrate included 12 to 15 members. The metathesis precursors were obtained from the amide coupling of tert-butyl 3-carboxyhex-5-enoate(2) with numerous side-chain alkenylated amino acid esters of general type(3)derived from L-lysine and L-ornithine.

  7. Evaluation of eye irritation by S-(-)-10,11-dihydroxyfarnesic acid methyl ester secreted by Beauveria bassiana CS1029.

    Science.gov (United States)

    Son, Hyeong-U; Lee, Sang-Han

    2013-10-01

    The aim of this study was to investigate whether S-(-)-10,11-dihydroxyfarnesic acid methyl ester produced by cell subtype Beauveria bassiana CS1029 causes acute toxicity when used for cosmetic purposes by performing an eye irritation test. New Zealand white (NZW) rabbits were treated with a 100 mg/dose of S-(-)-10,11-dihydroxyfarnesic acid methyl ester according to standard procedure guidelines. No significant changes in terms of ocular lesions of the cornea, turbidity of the cornea, swelling of the eyelid or ocular discharge were observed in the methyl ester-treated groups, while sodium dioctyl sulfosuccinate, a positive control, caused severe toxicity. The anatomical and pathological observations indicate that the methyl ester produced by Beauveria bassiana CS1029 did not induce eye irritation in the lenses of the rabbits. The data suggest that the methyl ester evaluated in this study has promising potential as a cosmetic ingredient that does not irritate the eye.

  8. 40 CFR 721.8450 - 2-Propenoic acid, 2-methyl-, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl ester.

    Science.gov (United States)

    2010-07-01

    ... ester. 721.8450 Section 721.8450 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.8450 2-Propenoic acid, 2-methyl-, 2- ethyl ester. (a) Chemical substance... acid, 2-methyl-, 2- ethyl ester, (PMN P-90-333) is subject to reporting under this section for...

  9. 40 CFR 721.1730 - Poly(oxy-1,2-ethanediyl), α-butyl-ω-hydroxy, ester with boric acid (H3BO3).

    Science.gov (United States)

    2010-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1730 Section 721.1730 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-butyl-ω-hydroxy, ester with...

  10. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Science.gov (United States)

    2010-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with...

  11. Decomposition products of glycidyl esters of fatty acids by heating.

    Science.gov (United States)

    Kimura, Wataru; Endo, Yasushi

    2017-03-01

    In this study, decomposition products of glycidyl palmitate (GP) of fatty acids heated at high temperature such as deep frying were investigated. When GP and tripalmitin (TP) were heated at 180 and 200 °C, they were decreased with heating time. The weight of GP was less than that of TP, although both GP and TP were converted to polar compounds after heating. The decomposition rate of GP was higher than TP. Both GP and TP produced considerable amounts of hydrocarbons and aldehydes during heating. Aldehydes produced from GP and TP included saturated aldehydes with carbon chain length of 3-10, while hydrocarbons consisted of carbon chain length of 8-15. It was observed that major hydrocarbons produced from GP during heating were pentadecane. Moreover, the level of carbon dioxide (CO2) released from GP was higher than that of TP. It was suggested that fatty acids in GE might be susceptible to decarboxylation. From these results, GP might be quickly decomposed to hydrocarbons, aldehydes and CO2 besides polar compounds by heating, in comparison with TP.

  12. Joint effects of dithiophosphoric acid ester and antioxidants on performance properties of mineral oil

    Energy Technology Data Exchange (ETDEWEB)

    Borshchevskii, S.B.; Shabanova, Ye.V.; Zagorodnyy, N.G.; Trofimov, G.A.

    1982-05-01

    High temperatures, catalytic effects of metals and environmental oxidation bring significant changes in lubricating oils. The joint effects of the methylbenzyl ester of diisobutyldithiophosphoric acid and various phenol and amine antioxidant additives were studied. At 200/sup 0/C, 2,2-methylene-bis(4-methyl-6-tert-butylphenol) and 2,6-di(tert-butyl)-4-methylphenol had a prooxidational effect, while 4,4-methylene-bis(2,6(tert-butyl)phenol), phenol-alpha-naphthylamine and the mixed products of phenol alkylation by styrene (A0-20) inhibited oxidation. A0-20 reduced the methylbenzyl ester's prooxidational action, while the others had little effect. At 180/sup 0/C in the presence of copper, all tested antioxidants but A0-20 inhibited oxidation and the methylbenzyl ester increased that action. Little change was noted in the M-11 lubricating oil tested because of the additives. The combination of A0-20 and the ester improved antiwear, antiscratch and antioxidation properties better than other combinations. 4 references, 2 figures.

  13. Use of citric acid esters as alternative fuel for diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Georg; Thuneke, Klaus; Remmele, Edgar [Technologie- und Foerderzentrum, Straubing (Germany); Schieder, Doris [Technische Univ. Muenchen, Straubing (Germany). Lehrstuhl fuer Chemie Biogener Rohstoffe

    2013-06-01

    Common fuels for (adapted) diesel engines are fossil diesel fuel, fatty acid methyl ester (FAME or biodiesel) or vegetable oils. Furthermore the citric acid esters tributylcitrate (TBC) and triethylcitrate (TEC) are expected to be a possible diesel substitute. Their use as fuel was applied for a patent in Germany in 2010. According to the patent applicant the advantages are low soot combustion, independence of energy imports due to the possibility of local production and a broad raw material base. Their fuel properties have been analysed in the laboratory and compared with the relevant fuel standards. Only some of the determined values are meeting the specifications, but on the other hand few rapeseed oil characteristics (e. g. oxidation stability and viscosity) can be improved if the citric acid esters are used as a blend component. The operating and emission behaviour of a vegetable oil compatible CHP unit fuelled with various rapeseed oil and TBC blends were investigated and a trouble free and soot emission reduced engine operation due to the high molecularly bound oxygen content was observed. Long term test runs are necessary for an entire technical validation. (orig.)

  14. Chromatographic analyses of fatty acid methyl esters by HPLC-UV and GC-FID

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Myller S.; Pinho, David M.M.; Suarez, Paulo A.Z., E-mail: psuarez@unb.br [Laboratorio de Materiais e Combustiveis, Instituto de Quimica, Universidade de Brasilia, DF (Brazil); Mendonca, Marcio A. [Faculdade de Agronomia e Medicina Veterinaria, Universidade de Brasilia, DF (Brazil); Resck, Ines S. [Laboratorio de Ressonancia Magnetica Nuclear, Universidade de Brasilia, DF (Brazil)

    2012-04-15

    An analytical method using high performance liquid chromatography with UV detection (HPLC-UV) (method A) was used for simultaneous determination of total amounts of triacylglycerides, diacylglycerides, monoacylglycerides and fatty acid methyl esters in alcoholysis of different oil (cotton, canola, sunflower, corn and soybean) samples. Analyses were carried out at 40 deg C for 20 min using a gradient of methanol (MeOH) and 2-propanol-hexane 5:4 (v/v) (PrHex): 100% of MeOH in 0 min, 50% of MeOH and 50% of PrHex in 10 min maintained with isocratic elution for 10 min. Another HPLC-UV method (method B) with acetonitrile isocratic elution for 34 min was used to determine the fatty acid composition of oils analyzing their methyl ester derivatives. Contents were determined with satisfactory repeatability (relative standard deviation, RSD < 3%), linearity (r{sup 2} > 0.99) and sensitivity (limit of quantification). Method B was compared with an official gas chromatographic method with flame ionization detection (GC-FID) from American Oil Chemists' Society (AOCS) in the determination of fatty acid methyl esters (FAME) in biodiesel real samples. (author)

  15. New fatty acid, aromatic ester and monoterpenic benzyl glucoside from the fruits of Withania coagulans Dunal.

    Science.gov (United States)

    Ali, Abuzer; Jameel, Mohammad; Ali, Mohammed

    2015-01-01

    The fruits of Withania coagulans Dunal (family: Solanaceae) are sweet, sedative, emetic, alterative and diuretic; used to treat asthma, biliousness, strangury, wounds, dyspepsia, flatulent colic, liver complaints and intestinal infections in the indigenous system of medicine. Phytochemical investigation of the methanolic extract of W. coagulans fruits led to the isolation of a new fatty acid, an aromatic ester and a monoterpenic benzyl glucoside characterised as n-octatriacont-17-enoic acid (3), geranilan-10-olyl dihydrocinnamoate (4) and geranilan-8-oic acid-10-olyl salicyloxy-2-O-β-D-glucofuranosyl-(6″→1‴)-O-β-D-glucofuranosyl-6‴-n-octadec-9‴',11‴'-dienoate (5) along with two known fatty acids, n-dotriacont-21-enoic acid (1) and n-tetratriacontanoic acid (2). The structures of isolated phytoconstituents were established on the basis of 1D and 2D NMR, FT-IR, UV, and MS data and chemical means.

  16. Scientific Opinion on the re-evaluation of montan acid esters (E 912 as a food additive

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS

    2013-06-01

    Full Text Available Following a request from the European Commission, the EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS was asked to deliver a scientific opinion re-evaluating the safety of montan acid esters (E 912 when used as a food additive. Montan acids are extracted from oxidised montan wax and esterified with ethylene glycol, 1,3-butanediol or triols, to form montan acid esters. Montan acid esters are authorised only for the surface treatment of fresh fruits. No data, specifically for montan acid esters, on toxicokinetics and reproductive and developmental toxicity were available. The available data on short-term and subchronic toxicity, genotoxicity and chronic toxicity and carcinogenicity were limited. Important deficiencies in the available studies on chronic toxicity and carcinogenicity were noticed. The data requested in the 1990s (i.e. chromosomal aberration in vitro, reproduction and teratogenicity studies, material characteristics, impurities, presence of PAHs were not submitted. Furthermore no data were submitted following an EFSA public call for data in 2012. The Panel identified some summary data in the European Chemicals Agency database (ECHA on registered substances that might have been relevant for the assessment of montan acid esters but the original study reports were not made available to EFSA. Based on these limitations in the toxicological database the Panel concluded that montan acid esters as a food additive could not be evaluated.

  17. Preparation and drug-loading properties of Fe{sub 3}O{sub 4}/Poly(styrene-co-acrylic acid) magnetic polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wensheng [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Coordination Chemistry Institute, School of Chemistry and Chemical Engineering and Life Science, Chaohu University, Chaohu 238000 (China); Shen, Yuhua, E-mail: s_yuhua@163.com [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Xie, Anjian [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Zhang, Weiqiang [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Coordination Chemistry Institute, School of Chemistry and Chemical Engineering and Life Science, Chaohu University, Chaohu 238000 (China)

    2013-11-15

    Fe{sub 3}O{sub 4}/poly(styrene-co-acrylic acid) magnetic polymer nanocomposites were synthesized by the dispersion polymerization method using styrene as hard monomer, acrylic acid as functional monomer, Fe{sub 3}O{sub 4} nanoparticles modified with oleic acid as core, and poly(styrene-co-acrylic acid) as shell. Drug-loading properties of magnetic polymer nanocomposites with curcumin as a model drug were also studied. The results indicated that magnetic polymer nanocomposites with monodisperse were obtained, the particle size distribution was 50–120 nm, and the average size was about 100 nm. The contents of poly(styrene-co-acrylic acid) and Fe{sub 3}O{sub 4} nanoparticles in magnetic polymer nanocomposites were 74% and 24.7%, respectively. The drug-loading capacity and entrapment efficiency were 2.5% and 44.4%, respectively. The saturation magnetization of magnetic polymer nanocomposites at 300 K was 20.2 emu/g without coercivity and remanence. The as-prepared magnetic polymer nanocomposites have not only lots of functional carboxyl groups but also stronger magnetic response, which might have potential applications in drug carrier and targeted drug release.

  18. Catalytic Autoxidation of Fatty Acid Methyl Esters from Jatropha Oil

    Directory of Open Access Journals (Sweden)

    Abebe K. Endalew

    2014-01-01

    Full Text Available Metal catalysts for transesterification of vegetable oils can cause autoxidation side reactions which reduces the fuel quality of the biodiesel. On the other side, oxidation of highly unsaturated oils can open opportunities for the synthesis of other important renewable chemical products. This study reports catalytic oxidation of fatty acids of Jatropha curcas oil (JCO by Li-CaO/Fe2(SO43 catalyst during transesterification at mild reaction conditions. The catalytic oxidation of the triglycerides was shown to be enhanced by the presence of lithium incorporated in the otherwise active catalyst combination of CaO/Fe2(SO43 used for high conversion into FAME. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS was used to assess the reaction products.

  19. Caffeic acid phenethyl ester prevents apoptotic cell death in the developing rat brain after pentylenetetrazole-induced status epilepticus.

    Science.gov (United States)

    Yiş, Uluç; Topçu, Yasemin; Özbal, Seda; Tuğyan, Kazım; Bayram, Erhan; Karakaya, Pakize; Yilmaz, Osman; Kurul, Semra Hız

    2013-11-01

    Population-based studies suggest that seizure incidence is highest during the first year of life, and early-life seizures frequently result in the development of epilepsy and behavioral alterations later in life. The early-life insults like status epilepticus often lead to epileptogenesis, a process in which initial brain injury triggers cascades of molecular, cellular, and network changes and eventually spontaneous seizures. Caffeic acid phenethyl ester is an active component of propolis obtained from honeybees and has neuroprotective properties. The aim of this study was to investigate whether caffeic acid phenethyl ester exerts neuroprotective effects on the developing rat brain after status epilepticus. Twenty-one dams reared Wistar male rats, and 21-day-old rats were divided into three groups: control group, pentylenetetrazole-induced status epilepticus group, and caffeic acid phenethyl ester-treated group. Status epilepticus was induced on the first day of experiment. Caffeic acid phenethyl ester injections (30 mg/kg intraperitoneally) started 40 min after the tonic phase of status epilepticus was reached, and the injections of caffeic acid phenethyl ester were repeated over 5 days. Rats were sacrificed, and brain tissues were collected on the 5th day of experiment after the last injection of caffeic acid phenethyl ester. Apoptotic cell death was evaluated. Histopathological examination showed that caffeic acid phenethyl ester significantly preserved the number of neurons in the CA1, CA3, and dentate gyrus regions of the hippocampus and the prefrontal cortex. It also diminished apoptosis in the hippocampus and the prefrontal cortex. In conclusion, this experimental study suggests that caffeic acid phenethyl ester administration may be neuroprotective in status epilepticus in the developing rat brain.

  20. Synthesis, Resolution, and Enantiomeric Purity Assay of 2-n-Butylbutanedioic Acid 4-t-Butyl Esters

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Racemic 2-n-butylbutanedioic acid 4-t-butyl esters were synthesized from methyl hexanoate and t-butyl α-iodoacetate via alkylation and subsequently selective hydrolyzation. The (R)-and (S)-2-n-butylbutanedioic acid 4-t-butyl esters were obtained by the resolution of the above-mentioned racemic compounds with(S)-( - ) or(R)-( + )-α-methylbenzylamine, respectively. The e.e. values of the two optical active products were determined to be above 99% by HPLC after the formation of two pairs of diastereoisomers with ( R)-( + )-α-methylbenzylamine and (S)-phenylalanine methyl ester.

  1. Catalytic Synthesis of Ethyl Ester of Acetyl Ferulic Acid with DCC/DMAP%DCC/DMAP 催化制备乙酰阿魏酸乙酯

    Institute of Scientific and Technical Information of China (English)

    石翛然

    2014-01-01

    Intermediate 3-( 4-acetoxy-3-methoxyphenyl ) acrylic acid was synthesized by 4-hydroxy-3-methoxybenzaldehyde, with dicyclohexyl carbodiimide ( DCC) and 4-dime-thylamino pyridine ( DMAP) as catalyst. Ethyl ester of acetyl ferulic acid was synthesized by esterification reaction.Target product was characterized by IR, elemental analysis and MS.The experimental results showed at room temperature, the amount of catalyst accounts for 3%of the acetyl ferulic acid, and reaction 4 h was the best condition.%以4-羟基-3-甲氧基苯甲醛为起始原料,合成了中间产物乙酰阿魏酸,再以N,N-二环己基碳二亚胺( DCC)和4-二甲胺基吡啶( DMAP)为催化剂,通过酯化反应制备了乙酰阿魏酸乙酯,各步产物通过红外光谱、质谱和元素分析对其结构进行表征确认。实验结果表明:在室温下,催化剂用量为乙酰阿魏酸用量的3%,反应时间为4 h的条件下,产率达到75%,为最优条件。

  2. SYNTHESIS OF SOAP-FREE ACRYLIC HYDROSOLS

    Institute of Scientific and Technical Information of China (English)

    Li Jia; Zong-hui Liu; De-qing Wei

    2002-01-01

    Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-freepolymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of reactioncondition on the morphology and particle size of the hydrosols was investigated. The minimum amount of acrylic acid in thehydrosols is 2%. The maximum weight average molecular weight (Mw) of polymer that assures soap-free emulsionconversion into hydrosol is about 1.2 × 105-1.3 × 105. The particle transforming process was investigated, and an obviouschange of particle diameter and morphology was observed.

  3. Antioxidant activity of propolis: role of caffeic acid phenethyl ester and galangin.

    Science.gov (United States)

    Russo, A; Longo, R; Vanella, A

    2002-11-01

    Propolis, a natural product produced by the honeybee, has been used for thousands of years in folk medicine for several purposes. The extract contains amino acids, phenolic acids, phenolic acid esters, flavonoids, cinnamic acid, terpenes and caffeic acid. It possesses several biological activities such as antiinflammatory, immunostimulatory, antiviral and antibacterial. The exact mode of physiological or biochemical mechanisms responsible for the medical effects, however, is yet to be determined. In this work, we have investigated the antioxidant activity of a propolis extract deprived of caffeic acid phenethyl ester (CAPE). In addition, the activity of CAPE and galangin was also examined. Propolis extract (with and without CAPE) and its active components showed a dose-dependent free radical scavenging effect, a significant inhibition of xanthine oxidase activity, and an antilipoperoxidative capacity. Propolis extract with CAPE was more active than propolis extract without CAPE. CAPE, used alone, exhibited a strong antioxidant activity, higher than galangin. The experimental evidence, therefore, suggests that CAPE plays an important role in the antioxidant activity of propolis.

  4. Synthesis of a proline-modified acrylic acid copolymer in supercritical CO2 for glass-ionomer dental cement applications.

    Science.gov (United States)

    Moshaverinia, Alireza; Roohpour, Nima; Darr, Jawwad A; Rehman, Ihtesham U

    2009-06-01

    Supercritical (sc-) fluids (such as sc-CO(2)) represent interesting media for the synthesis of polymers in dental and biomedical applications. Sc-CO(2) has several advantages for polymerization reactions in comparison to conventional organic solvents. It has several advantages in comparison to conventional polymerization solvents, such as enhanced kinetics, being less harmful to the environment and simplified solvent removal process. In our previous work, we synthesized poly(acrylic acid-co-itaconic acid-co-N-vinylpyrrolidone) (PAA-IA-NVP) terpolymers in a supercritical CO(2)/methanol mixture for applications in glass-ionomer dental cements. In this study, proline-containing acrylic acid copolymers were synthesized, in a supercritical CO(2) mixture or in water. Subsequently, the synthesized polymers were used in commercially available glass-ionomer cement formulations (Fuji IX commercial GIC). Mechanical strength (compressive strength (CS), diametral tensile strength (DTS) and biaxial flexural strength (BFS)) and handling properties (working and setting time) of the resulting modified cements were evaluated. It was found that the polymerization reaction in an sc-CO(2)/methanol mixture was significantly faster than the corresponding polymerization reaction in water and the purification procedures were simpler for the former. Furthermore, glass-ionomer cement samples made from the terpolymer prepared in sc-CO(2)/methanol exhibited higher CS and DTS and comparable BFS compared to the same polymer synthesized in water. The working properties of glass-ionomer formulations made in sc-CO(2)/methanol were comparable and better than the values of those for polymers synthesized in water.

  5. CHEMOTHERAPEUTIC POLYMERS ⅩⅩⅢ SYNTHESIS AND ANTITUMOR ACTIVITY OF POLYPHOSPHATES CONTAINING BOTH NUCLEIC ACID BASE AND PHOSPHONOACETIC ACID ETHYL ESTER

    Institute of Scientific and Technical Information of China (English)

    ZHUO Renxi; LIU Zhenghua; LI Li

    1989-01-01

    Eight new polyphosphates containing both nucleic acid base and phosphonoacetic acid ethyl ester were synthesized by the polycondensation of P, P- dichloride of phosphonoacetic acid ethyl ester with 1, 3-dihydroxyalkyl - 5 - fluorouracil, 1,3 - dihydroxyalkyl - uracil and 1, 3 - dihydroxyalkylthymine. These polyphosphates were tested against Ehrlich Ascites Carcinoma in mice. Polymer Ⅱa and Ⅱc exhibited excellent antitumor activity. Ⅱc also showed lower toxicity.

  6. Integrated process of distillation with side reactors for synthesis of organic acid esters

    Science.gov (United States)

    Panchal, Chandrakant B; Prindle, John C; Kolah, Aspri; Miller, Dennis J; Lira, Carl T

    2015-11-04

    An integrated process and system for synthesis of organic-acid esters is provided. The method of synthesizing combines reaction and distillation where an organic acid and alcohol composition are passed through a distillation chamber having a plurality of zones. Side reactors are used for drawing off portions of the composition and then recycling them to the distillation column for further purification. Water is removed from a pre-reactor prior to insertion into the distillation column. An integrated heat integration system is contained within the distillation column for further purification and optimizing efficiency in the obtaining of the final product.

  7. NMR Studies of a New Binding Mode of the Amino Acid Esters by Porphyrinatozinc(Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The binding mode of the amino acid ethyl esters(guest) by 5-(2-carboxylphenyl)-10,15,20-triphenylporphyrinatozinc(Ⅱ)(host 1) was studied by means of 1H NMR spectra. The binding mode is the hydrogen-bonding between the amino group of the guest and the carboxyl group of host 1 plus the coordination between the zinc atom of porphyrinatozinc(Ⅱ) and the carbonyl group of the guest. This is a novel binding mode of the metalloporphyrin to amino acid derivatives.

  8. Preparation of metal adsorbent from poly(methyl acrylate)-grafted-cassava starch via gamma irradiation

    Science.gov (United States)

    Suwanmala, Phiriyatorn; Hemvichian, Kasinee; Hoshina, Hiroyuki; Srinuttrakul, Wannee; Seko, Noriaki

    2012-08-01

    Metal adsorbent containing hydroxamic acid groups was successfully synthesized by radiation-induced graft copolymerization of methyl acrylate (MA) onto cassava starch. The optimum conditions for grafting were studied in terms of % degree of grafting (Dg). Conversion of the ester groups present in poly(methyl acrylate)-grafted-cassava starch copolymer into hydroxamic acid was carried out by treatment with hydroxylamine (HA) in the presence of alkaline solution. The maximum percentage conversion of the ester groups of the grafted copolymer, % Dg=191 (7.63 mmol/g of MA), into the hydroxamic groups was 70% (5.35 mmol/g of MA) at the optimum condition. The adsorbent of 191%Dg had total adsorption capacities of 2.6, 1.46, 1.36, 1.15 and 1.6 mmol/g-adsorbent for Cd2+, Al3+, UO22+, V5+ and Pb2+, respectively, in the batch mode adsorption.

  9. The use of dielectric spectroscopy for the characterisation of the precipitation of hydrophobically modified poly(acrylic-acid) with divalent barium ions

    DEFF Research Database (Denmark)

    Christensen, Peter Vittrup; Keiding, Kristian

    2009-01-01

    The use of dielectric spectroscopy as a monitor for coagulation processes was investigated. Hydrophobically modified poly(acrylic-acid) polymers were used as model macromolecules and coagulated with barium ions. The coagulation process was quantified using a photometric dispersion analyser, thereby...

  10. Systematic investigation of the synthesis of core-shell poly(styrene-co-acrylic acid) colloids with varying shell thickness and core diameter

    DEFF Research Database (Denmark)

    Hinge, Mogens; Keiding, Kristian

    2006-01-01

    the morphology of the material for an specific application is going on. It is known from SFEP of styrene that the final colloidal size can be controlled by adjusting the ionic strength of the synthesis feed [1] and it is suggested that adding acrylic acid to the synthesis will result in a change...... in polymerization locus from the core to the surface [2]. There is at present not performed a systematically investigation in controlling the core size and shell thickness of poly(styrene-co-acrylic acid) core-shell colloids  (poly(ST-co-AA)).   Poly(ST-co-AA) colloids were synthesized by free-radical surfactant......-free emulsion co-polymerization (SFECP) at 70°C, using styrene as monomer and acrylic acid as co-monomer. Different batches of poly(ST-co-AA) colloids were synthesized with varying ionic strength and acrylic acid concentrations in the synthesis feed. The produced poly(ST-co-AA) colloids were analysed...

  11. Radiation synthesis of pH-sensitive hydrogels from {beta}-cyclodextrin-grafted PEG and acrylic acid for drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Chen Jie; Rong Liang [Department of Chemical Engineering and Technology, School of Environmental and Chemical Engineering, Shanghai University, Baoshan, Shanghai 200444 (China); Lin Han, E-mail: linhan1205@yahoo.com.cn [Department of Chemical Engineering and Technology, School of Environmental and Chemical Engineering, Shanghai University, Baoshan, Shanghai 200444 (China); Xiao Ruijia; Wu Huifeng [Department of Chemical Engineering and Technology, School of Environmental and Chemical Engineering, Shanghai University, Baoshan, Shanghai 200444 (China)

    2009-07-15

    A water-soluble macromonomer (PEG-{beta}-CD) was synthesised by reaction of {beta}-cyclodextrin with poly(ethylene glycol) diglycidyl ether. Then, a novel hydrogel with pH-sensitivity was prepared by irradiating the mixture of acrylic acid and PEG-{beta}-CD with electron beam. Compared with the normal PAAc hydrogel, this novel hydrogel had a higher swelling ratio at pH 3-8. 5-Fluorouracil (5-FU) was chosen as a model drug, and the kinetics of 5-FU releasing behavior was studied. Compared with the PAAc hydrogel, the results showed the release time of 5-FU from the cyclodextrin containing hydrogel was prolonged. It may be ascribed to the formation of inclusion complexes between the drug molecules and cyclodextrin groups.

  12. Poly(acrylic acid)-directed synthesis of colloidally stable single domain magnetite nanoparticles via partial oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Altan, Cem L. [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey); Laboratory of Materials and Interface Chemistry & Soft Matter cryoTEM Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Gurten, Berna [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey); Sadza, Roel [Laboratory of Materials and Interface Chemistry & Soft Matter cryoTEM Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Yenigul, Elcin [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey); Sommerdijk, Nico A.J.M., E-mail: n.sommerdijk@tue.nl [Laboratory of Materials and Interface Chemistry & Soft Matter cryoTEM Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Bucak, Seyda, E-mail: seyda@yeditepe.edu.tr [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey)

    2016-10-15

    Octahedral, single domain magnetite nanoparticles with average size of ~55 nm were synthesized through oxidative aging of a ferrous hydroxide (Fe(OH){sub 2}) precursor at high pH in water. The synthesis was also carried out in the presence of the hydrophilic polymer poly(acrylic acid). Presence of the polymer changed the particle morphology from octahedral to spherical while average size decreased to 40–50 nm. Although these particles have a tendency to precipitate due to their high magnetic moment, dispersions of these particles were obtained in the presence of this particular polymer which made the particles stable in water for several days making them suitable for various biotechnological applications such as cell separation owing to their low toxicity. - Highlights: • Stable, single domain magnetite nanoparticles are synthesized via partial oxidation. • Particles are readily stabilized in water by a biocompatible polymer. • Steric barrier is essential for the stabilization of large magnetite nanoparticles.

  13. Improvement in the behavior of bromelain coupled to pNIPAm polymers containing acrylamide or acrylic acid

    Directory of Open Access Journals (Sweden)

    Rubab Mahmood

    2014-08-01

    Full Text Available Bromelain was coupled to N-isopropyl acrylamide (NIPAmpolymers, synthesized using NIPAm and various concentrations of acrylamide (Ac or acrylic acid (AAc. Incorporation of Ac/AAcinto the polymer increased the LCST (lower critical solutiontemperature in a concentration dependent manner but AAc wasmore effective in this regard; the LCST rose to 40°C when 6 percent AAc was used. Incorporation of Ac/AAc increased the coupling of enzyme to the polymer and the η (effectiveness factor of the coupled enzyme, moderately. Various studies indicate that such incorporation of hydrophilic monomers into the polymer does not impair its capacity to couple enzyme or expression of the activity of bound enzyme but seems to actually improve the stability of the enzyme against heat induced inactivation and alkaline pH.

  14. Removal of reactive dyes from textile wastewater by immobilized chitosan upon grafted Jute fibers with acrylic acid by gamma irradiation

    Science.gov (United States)

    Hassan, Mahmoud S.

    2015-10-01

    Jute fibers were grafted with acrylic acid by gamma irradiation technique. Chitosan was immobilized upon the grafted Jute fibers to be used as an adsorbent for waste reactive dye. The treated Jute fibers were characterized by using of Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of Jute treatment on its thermal stability by using thermogravimetric analysis (TGA) and its mechanical properties were investigated. The adsorption isotherm and the different factors affecting the dye adsorption such as pH and contact time were also studied. It was found that the dye adsorption was enhanced in the low pH range and increased with increasing of the contact time, regardless of temperature change.

  15. PHOTO-INDUCED DOPED POLYANILINE BY THE VINYLIDENE CHLORIDE AND METHYL ACRYLATE COPOLYMER AS PHOTO ACID GENERATOR

    Institute of Scientific and Technical Information of China (English)

    LI Suzhen; WAN Meixiang

    1997-01-01

    The emeraldine base form of polyaniline (PANI) can be doped by a photo-induced doping method. In this method a copolymer of vinylidene chloride and methyl acrylate (VCMAC) was used as photo acid generator which can release proton when it is exposed to ultraviolet light (λ = 254 nm). The structure of PANI-VCMAC system before and after irradiation was characterized by elemental analysis, IR, XPS, and SEM images. Results obtained indicate that the photo-induced doping characteristics, such as doping position and type of charge carriers, are similar to that of PANI doped with HCl. The poor roomtemperature conductivity (~ 10-5S/cm) of PANI-VCMAC system after irradiation may be due to low doping degree (~pH= 3) and the difference in morphology as compared with PANI-HCl film.

  16. Surface grafted chitosan gels. Part I. Molecular insight into the formation of chitosan and poly(acrylic acid) multilayers

    DEFF Research Database (Denmark)

    Liu, Chao; Thormann, Esben; Claesson, Per M.

    2014-01-01

    Composite polyelectrolyte multilayers of chitosan and low molecular weight poly(acrylic acid) (PAA) have been assembled by sequential adsorption as a first step toward building a surface anchored chitosan gel. Silane chemistry was used to graft the first chitosan layer to prevent film detachment...... and decomposition. The assembly process is characterized by nonlinear growth behavior, with different adsorption kinetics for chitosan and PAA. In situ analysis of the multilayer by means of surface sensitive total internal reflection Raman (TIRR) spectroscopy, combined with target factor analysis of the spectra...... molecular weight chitosan shows a similar behavior, although to a much lower extent. Our data demonstrate that the charged monomeric units of chitosan are mainly compensated by carboxylate ions from PAA. Furthermore, the morphology and mechanical properties of the multilayers were investigated in situ using...

  17. Poly(acrylic acid)-directed synthesis of colloidally stable single domain magnetite nanoparticles via partial oxidation

    Science.gov (United States)

    Altan, Cem L.; Gurten, Berna; Sadza, Roel; Yenigul, Elcin; Sommerdijk, Nico A. J. M.; Bucak, Seyda

    2016-10-01

    Octahedral, single domain magnetite nanoparticles with average size of ~55 nm were synthesized through oxidative aging of a ferrous hydroxide (Fe(OH)2) precursor at high pH in water. The synthesis was also carried out in the presence of the hydrophilic polymer poly(acrylic acid). Presence of the polymer changed the particle morphology from octahedral to spherical while average size decreased to 40-50 nm. Although these particles have a tendency to precipitate due to their high magnetic moment, dispersions of these particles were obtained in the presence of this particular polymer which made the particles stable in water for several days making them suitable for various biotechnological applications such as cell separation owing to their low toxicity.

  18. Thermoresponsive Photonic Crystal: Synergistic Effect of Poly(N-isopropylacrylamide)-co-acrylic Acid and Morpho Butterfly Wing.

    Science.gov (United States)

    Xu, Dongdong; Yu, Huanan; Xu, Qun; Xu, Guiheng; Wang, Kaixi

    2015-04-29

    In this work, we report a simple method to fabricate smart polymers engineered with hierarchical photonic structures of Morpho butterfly wing to present high performance that are capable of color tunability over temperature. The materials were assembled by combining functional temperature responsivity of poly(N-isopropylacrylamide)-co-acrylic acid (PNIPAm-co-AAc) with the biological photonic crystal (PC) structure of Morpho butterfly wing, and then the synergistic effect between the functional polymer and the natural PC structure was created. Their cooperativity is instantiated in the phase transition of PNIPAm-co-AAc (varying with the change of temperature) that can alter the nanostructure of PCs, which further leads to the reversible spectrum response property of the modified hierarchical photonic structures. The cost-effective biomimetic technique presented here highlights the bright prospect of fabrication of more stimuli-responsive functional materials via coassembling smart polymers and biohierarchical structures, and it will be an important platform for the development of nanosmart biomaterials.

  19. Synthesis, characterization and electrical properties of Fe3O4/poly(vinyl alcohol-co-acrylic acid) nanocomposites

    Science.gov (United States)

    P, Jayakrishnan; Ramesan, M. T.

    2014-10-01

    This work focused on the synthesis of magnetite (Fe3O4)/poly(vinyl alcohol-co-acrylic acid) nanocomposite by in situ polymerization. The composite were characterized by FT-IR spectroscopy, XRD, SEM, TGA, AC and DC conductivity measurements. The spectroscopic studies revealed the molecular interaction between the polymer and nanocomposites. SEM, XRD indicated the uniform dispersion of nanoparticle inside the molecular chain of copolymer. TGA studies indicated the excellent thermal stability of copolymer nanocomposites. AC and DC conductivity of nanocomposites were higher than that of the copolymer and conductivity values were significantly increased with increase in concentration of metal oxide nanoparticles. These properties suggest that the polymer composite can be used as multifunctional material for nanoelectronics.

  20. Engineering and systems level analysis of Saccharomyces cerevisiae for production of 3 hydroxypropionic acid via malonyl CoA reductase dependent pathway

    DEFF Research Database (Denmark)

    Kildegaard, Kanchana Rueksomtawin; Jensen, Niels Bjerg; Schneider, Konstantin;

    2016-01-01

    In the future, oil- and gas-derived polymers may be replaced with bio-based polymers, produced from renewable feedstocks using engineered cell factories. Acrylic acid and acrylic esters with an estimated world annual production of approximately 6 million tons by 2017 can be derived from 3...