bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of antibacterial poly(methyl methacrylate) by solution blending with water‐insoluble antibacterial agent poly[(tert‐buty1amino) ethyl methacrylate]
Authors: Zuo Huajiang , Wu Dingcai , Fu Ruowen 
Published: February 2012

AbstractA simple and effective way was developed to prepare antibacterial poly(methyl methacrylate) (PMMA) materials from commercial PMMA and synthesized poly[2‐(tert‐butylamino) ethyl methacrylate] (PTBAEMA) by solution blending and solvent evaporation methods. The chemical structure of as‐synthesized PTBAEMA was characterized by FTIR and 1H‐NMR, and the molecular weight (Mw) and polydispersity index was determined by Gel Permeation Chromatograph. The two components, that is, PMMA and PTBAEMA, were partially miscible and of regular domain size and shape as revealed by SEM observation. Antibacterial assay revealed PMMA/PTBAEMA blends inherited the good antibacterial activity of PTBAEMA against both Staphylococcus aureus and Escherichia coli, no matter whether the bacteria were waterborne or airborne. Besides, the antibacterial performance of PMMA/PTBAEMA blends depended on the Mw and dosage of PTBAEMA, and type of bacteria strain. Furthermore, it was proved that PMMA/PTBAEMA blends killed bacteria on direct contact without releasing active component, which sufficiently met the demand of developing environment‐friendly antibacterial materials. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of the aggregation structure on the thermal shrinkage of polyacrylonitrile fibers during the heat‐treatment process
Authors: Wang Bin , Zhao Chun , Xiao Shijie , Zhang Jing , Xu Lianghua 
Published: February 2012

AbstractSecondary thermal shrinkage or chemical shrinkage involved in the thermal shrinkage of polyacrylonitrile (PAN) fibers was not only associated with the cyclization degree but also the thermal mobility of molecular chains in the aggregation structures during crosslinking. In this study, the cyclization process was monitored with differential scanning calorimetry and IR spectroscopy. The evolution of aggregation structures throughout cyclization and variations in the secondary shrinkage for the PAN fibers were characterized with wide‐angle X‐ray diffraction and thermal mechanical analysis, respectively. The results show that with increasing temperature, the cyclization degree increased; the cyclization occurred first in amorphous regions and then extended to the crystalline regions. Correspondingly, the secondary shrinkage also increased and could be separated into two stages: those of the amorphous and crystalline phases. The shrinkage of the crystalline regions was much bigger than that of the amorphous regions. For fibers with different aggregation structures, the crystallinity affected the cyclization degree in the amorphous and crystalline regions and resulted in the difference in total shrinkage. Furthermore, because the unoriented molecular chains in both the amorphous and crystalline regions shrank more after cyclization, the shrinkage of both regions was primarily decided by the level of orientated molecular chains participating in the cyclization. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synergy of magnesium and calcium oxides in intumescent flame‐retarded polypropylene
Authors: Ma Zhi‐Ling , Fan Cong‐Ran , Lu Guang‐Yu , Liu Xiu‐Ying , Zhang Hong 
Published: February 2012

AbstractAn intumescent flame retardant (IFR), pentaerytheritol phosphate ester melamine salt (PPEM) was synthesized and chemically modified by magnesium oxide (MgO) or/and calcium oxide (CaO), respectively. The fire retardant efficiency of MgO and CaO as synergistic agents in polypropylene (PP) was evaluated by normal fire testing methods. The results showed that MgO and CaO exhibited a synergistic effect on fire retardancy of PP. The addition of 0.2% of MgO or CaO into PP/PPEM composite could decrease the self‐extinguishing time and improve the limited oxygen index (LOI) obviously. The cone calorimeter (CONE) tests and the thermal analysis revealed that the introduction of MgO and CaO neutralized the acidity of PPEM, which leads to a thermal stabilization and a delay of the intumescent process of the system, and promote the formation of a high quality charred layer which can prevent PP from decomposing. Thus, a suitable amount of MgO and CaO acts as a synergistic agent in the flame‐retarded PP/PPEM system. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of corn starch content in thermoplastic starch/low‐density polyethylene blends on their mechanical and flow properties
Authors: Sabetzadeh Maryam , Bagheri Rouhollah , Masoomi Mahmood 
Published: February 2012

AbstractThe aim of this work is to prepare low‐density polyethylene (LDPE)/thermoplastic corn starch (TPCS) compounds containing the highest amount of starch for biodegradable applications. It is intended to increase concentration of corn starch into LDPE without affecting basic required mechanical properties of LDPE plastics for disposable products. LDPE/TPCS blends containing different contents of TPCS (0–40 wt %) and a constant amount of LDPE grafted maleic anhydride [PE‐g‐MA (3 wt %)] are prepared using a single‐screw extruder. The prepared blends are evaluated for their mechanical, flow, and water absorption properties. Scanning electron micrographs of the samples show improvement in dispersion of the starch particles in LDPE matrix in the presence of PE‐g‐MA as a compatibilizer. The Young's modulus and impact strength properties reduce by increasing corn starch content in TPCS. The ultimate tensile strength and elongation at break of the samples show that the blends with 25 wt % TPCS have the required mechanical properties to produce plastic packaging products, as evidenced by ASTM D 4976‐04. The results of rheological tests indicate that as shear rate increases, the apparent viscosity of the blends decreases (shear thinning). The addition of starch to LDPE also decreases the melt flow index values of the samples. The water absorption of the samples increases with increasing starch concentrations at a constant time of water immersion. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Electrosynthesis and characterization of a new multielectrochromic copolymer of 1,4‐bis(2‐thienyl) benzene with 3,4‐ethylenedioxythiophene
Authors: Cui Chuansheng , Xu Lianyi , Zhao Jinsheng , He Qingpeng , Wang Bin 
Published: February 2012

AbstractA copolymer based on 1,4‐bis(2‐thienyl) benzene (BTB) and 3,4‐ethylenedioxythiophene was electrochemically synthesized in acetonitrile containing sodium perchlorate (NaClO4). Cyclic voltammetry, ultraviolet–visible spectroscopy, and Fourier transform infrared analyses confirmed that the resulting polymer was a copolymer rather than a blend or a composite of the respective homopolymers. Poly(1,4‐bis(2‐thienyl) benzene) has only two colors; it switches between yellow in the neutral state and green in the oxidized state, whereas the poly[1,4‐bis(2‐thienyl) benzene‐co‐3,4‐ethylenedioxythiophene] (PBTBE) film exhibited five different colors (brown–red, orange–yellow, yellowish green, green, and blue). This revealed distinct electrochromic properties from that of the BTB homopolymer film. The maximum optical contrast (ΔT %) and response time of the copolymer film were measured to be 27.8% and 0.51 s, respectively, at 780 nm. An electrochromic device (ECD) based on PBTBE and poly(3,4‐ethylenedioxythiophene) was also constructed and characterized. This ECD showed a ΔT % value of 22.2% in the visible region with a response time of 0.43 s at 616 nm. The coloration efficiency of the device was calculated to be 129 cm2/C at 616 nm. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Solid‐phase extraction of S‐(‐)‐amlodipine from plasma with a uniformly sized molecularly imprinted polymer
Authors: Luo Kaixia , Liu Meng , Fu Qiang , Amut Elijan , Zeng Aiguo , Chang Chun 
Published: February 2012

AbstractTo specifically extract S‐(‐)‐amlodipine from plasma, uniformly sized molecularly imprinted polymers (MIPs) for S‐(‐)‐amlodipine were prepared in an aqueous system by multistep swelling and polymerization with methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, and toluene as a porogen. Scanning electron microscopy was used to identify the structural features of the obtained polymers. 1H‐NMR and high‐performance liquid chromatographic analysis were performed to explore the possible recognition mechanism. The results reveal that spherical polymer beads with uniform size and good monodispersity were obtained, and the MIPs showed specific recognition ability for the template molecule. The ionic hydrophobic and hydrogen‐bonding interactions were inferred to play an important role in the recognition mechanism. The results indicate that the MIPs could be used as a solid‐phase extraction sorbent for the concentration and purification of S‐(‐)‐amlodipine from plasma with a high efficiency. The linear range was 0.25–8.00 μg/mL with a correlation coefficient of 0.9948. The average recovery was 98.3% with relative standard deviation (RSD) less than 9.1%. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Enzyme‐catalyzed ring‐opening polymerization of cyclic esters in the presence of poly(ethylene glycol)
Authors: Sobczak Marcin 
Published: February 2012

AbstractLow‐molecular‐weight polyesters were obtained by the ring‐opening homopolymerization and copolymerization reaction of ϵ‐caprolactone, rac‐ or L‐lactide, and glycolide in the presence of poly(ethylene glycol) with an enzyme catalyst, a lipase from Candida antarctica, Pseudomonas cepacia, or Pseudomonas fluorescens. The influence of several parameters, including time, temperature, and enzyme and monomer concentration, on the polymerization rate was studied. The resulting polymers were characterized by 1H‐NMR or 13C‐NMR, Fourier transform infrared spectroscopy, matrix‐assisted laser desorption/ionization–time of flight mass spectroscopy, and gel permeation chromatography. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Nanostructured membranes based on cellulose acetate obtained by electrospinning, part 1: Study of the best solvents and conditions by design of experiments
Authors: Nista Silvia V. Guerra , Peres Leila , D'Ávila Marcos A. , Schmidt Flávio L. , Innocentini Mei Lucia H. 
Published: February 2012

AbstractThe electrospinning of cellulose acetate (CA) was investigated to develop biodegradable nanostructured membranes for the controlled release of drugs used to treat skin wounds. CA nanofibers were successfully prepared via the electrospinning in the four mixed solvents acetic acid : water; acetone : water; DMAc : acetone; DMAc : acetone : water. Design of experiments (DOE) was applied to see what combinations of parameters could affect the production of electrospun microfibers and nanofibers to optimize the process. The results of this work indicated that both the processing parameters and the solvent mixtures were responsible for the fiber diameter and nanostructure membrane appearance. The optimized condition for each solvent mixture was obtained and compared with each one of the others. The best conditions achieved were dimethylacetamida (DMAc) : acetone with 17% of CA, which provided homogeneous and free bead fibers with an average diameter of 295 nm. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of kinetics coefficients on ternary phase separation during the wet spinning process
Authors: Han Yu , Wang Jun , Zhang Hongdong 
Published: February 2012

AbstractA new Monte Carlo diffusion model is employed to simulate the phase separation of the ternary system during wet spinning process. Our results illustrate the thermodynamics parameters are the primary factors in morphology determination during the phase separation process. Meanwhile by varying kinetic parameters different fiber structures ranging from dust‐like, finger‐like to sponge‐like morphologies are obtained. The morphological patterns are discussed in relation to the rate of particle exchange and the phase diagram. On the basis of the systematical simulation experiments we propose how the competition between segment–solvent and solvent–nonsolvent exchange determines the ultimate fiber morphologies in spinning solution.© 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Study on the mechanism of the formation of polyhedral oligomeric silsesquioxanes by the 2D correlation infrared spectral
Authors: Qu Yanbin , Huang Guangsu , Wang Xiaoan , Li Jiali 
Published: February 2012

AbstractSynthesis of polyhedral oligomeric silsesquioxanes (POSS) by the hydrolytic condensation reaction of trifunctional organosilanes [e.g., RSiCl3 or RSi(OR)3] may have achieved success. However, the exact formation mechanism of POSS, especially, an evolution process in the reaction still remains unclear. In this work, a real‐time FTIR was carried out to trace the synthesis process of POSS. It was found that linear siloxanes, cyclic siloxanes, and cage‐like polysiloxanes were formed during the reaction. With the help of generalized two‐dimensional (2D) correlation analysis, we obtained exact sequential change among the three siolxanes, with the linear silicons formed initially. Following this was the emergence of cyclic siloxanes, and finally the cage‐like polysiloxanes. Consequently, we not only proved the existence of the linear and cyclic siloxanes but also accurately detected the sequential change of the siloxanes in the process, which exhibited an intact and visual evolution process of POSS formation. Based on this, the reaction mechanism is presented. Finally, the chemical structure of cage‐like products was further characterized by 29Si‐NMR and GPC measurements. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Developing chromic dyeable PET nanocomposites: The dye absorption and complex formation mechanisms
Authors: Dastjerdi Roya , Mojtahedi M. R. M. , Heidari N. 
Published: February 2012

AbstractThis research aimed to investigate the possibility of enhancement of polyethylene terephthalate (PET) dyeability using nanotechnology. Different kinds of disperse, acidic, and chromic dyes were used for dyeing of produced PET/silver nanocomposite fine multifilament yarns produced at the take up speeds of 3000 m min−1 and their prepared fabrics. Dyeability improved by using acidic dyes. However, the more promotion effect was achieved by chromic dyes. No effect on absorption of disperse dyes revealed that no physical effect can be considered for dye absorption. The electrostatic interaction between silver and acidic dye molecules and forming the coordinative bonds with chromic dye molecules on nanocomposite yarns and fabrics were concluded and thoroughly discussed. Applying chromic dye with the more potential of creating coordinative bonds intensified the improvement of dyeability. Optimized silver ratio for the dyeability enhancement was affected by the mechanisms of dye absorptions discussed and proven by investigating dye concentrations in the effluent baths after the dyeing processes. It has been found that the steric hindrance is the key factor for absorption of chromic dyes; however, it is different in the case of acidic dyes, well discussed according to the dye absorptions mechanisms. The results can be also considered as evidence to prove forming the coordinative bonds with chromic dye molecules. This has also been confirmed by appearing a bathochromic shift in the absorption peaks by increasing dyeability using chromic dye. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The influence of low‐ and high‐linear energy transfers on some physical properties of poly(methyl‐methacrylate) samples
Authors: Eissa Mostafa F. , Kaid Maysa A. , Kamel Nasser A. 
Published: February 2012

AbstractClear poly(methyl‐methacrylate)—PMMA—dosimeter is widely used in food irradiations. Positron annihilation lifetime spectroscopy (PALS) is one of the unique tools used for studying free‐volumes and open‐volume type defects in solid media. The Vicker's microhardness measurements offer a simple and nondestructive tool for investigating the mechanical behavior of polymer materials. PALS as well as microhardness measurements were carried out for PMMA samples, irradiated with low‐ and high‐linear energy transfers (LET). The low‐LET irradiations were provided at lethal doses of gamma radiations for vegetative bacteria. Such irradiations showed a chain scission in the PMMA samples. High‐LET irradiations showed behavior different from the low‐LET ones. The observed behavior depends on the alpha particle fluence. The microhardness testing was carried out for virgin and irradiated PMMA samples at high‐LET. A negative correlation was found between PALS measurements and microhardness results. The optical characteristics and structural studies for the virgin and irradiated PMMA samples were in agreement with the PALS and microhardness measurements. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Electrocatalytic performance of Pt supported on polyaniline‐poly(styrene sulfonate) hydrogel
Authors: Jia Yujie , Jiang Jianchun , Sun Kang , Dai Tingyang 
Published: February 2012

AbstractA new type of polyaniline‐poly (styrene sulfonate) (PAn‐PSS) hydrogel was fabricated with high concentrations of aniline (An) and PSS via supramolecular self‐assembly. Then 30 segments of cyclic voltammograms from −0.2 to 0.8 V were conducted to deposit the Pt particles on the surface of the hydrogel. For comparison, PAn‐PSS colloid was synthesized with the ordinary method. The morphology and composition of the PAn‐PSS hydrogel–Pt and PAn‐PSS colloid–Pt were investigated by the TEM and EDX measurements. Furthermore, the shift of the feature bands in FTIR and UV–vis spectra confirms that the PAn‐PSS hydrogel has interactions with Pt. So the Pt particles are dispersed and the electrons are shuttled more freely, which is beneficial for the electrochemical performance. The cyclic voltammograms and chronoamperometric measurements show that Pt supported on the PAn‐PSS hydrogel has preferable electrocatalytic performance toward the oxidation of methanol than the one on PAn‐PSS colloid. Hence, PAn‐PSS hydrogel–Pt can be a promising catalyst for methanol in fuel cells. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Hydroxyalkyl derivatives of phenyldiamine as modifiers for unsaturated polyester resins. II. derivatives of phenyl‐1,3‐diamine
Authors: Duliban Jerzy 
Published: February 2012

AbstractThe results are presented on the synthesis of new modifiers and on functioning of these modifiers in unsaturated polyester (UP) resins. The modifiers were obtained by reacting ethylene oxide or propylene oxide with phenyl‐1,3‐diamine. The effect of the modifiers and cobalt accelerator on the reactivity of resins was studied. When used in the amount of up to 1.50 wt %, the amines substantially (several times) reduced the gelation time of modified UPs. The reactivity of resins, however, improved in expense of their stability. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Progressive Anatomical Closure of Foramen Ovale in Normal Neonatal Mouse Hearts
Authors: Cole‐Jeffrey Colleen T. , Terada Ryota , Neth Matthew R. , Wessels Andy , Kasahara Hideko 
Published: February 2012

AbstractIn the prenatal heart, right‐to‐left atrial shunting of blood through the foramen ovale is essential for proper circulation. After birth, as the pulmonary circulation is established, the foramen ovale functionally closes as a result of changes in the relative pressure of the two atrial chambers, ensuring the separation of oxygen depleted venous blood in the right atrium from the oxygenated blood entering the left atrium. Little is known regarding the process of anatomical closure of the foramen ovale in the postnatal heart. Genetically engineered mouse models are powerful tools to study heart development and to reveal mechanisms underlying cardiac anomalies, including defects in atrioventricular septation. Using three‐dimensional reconstructions of serial sectioned hearts at early postnatal Days 2–7, we show a progressive reduction in the size of the interatrial communication throughout this period and complete closure by postnatal Day 7. Furthermore we demonstrate that fusion of the septum primum and septum secundum occurs between 4 weeks and 3 months of age. This study provides a standard timeline for morphological closure of the right–left atrial communication and fusion between the atrial septa in normal mouse hearts. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Genome‐wide association analysis of juvenile idiopathic arthritis identifies a new susceptibility locus at chromosomal region 3q13
Authors: Thompson Susan D. , Marion Miranda C. , Sudman Marc , Ryan Mary , Tsoras Monica , Howard Timothy D. , Barnes Michael G. , Ramos Paula S. , Thomson Wendy , Hinks Anne , Haas Johannes‐Peter , Prahalad Sampath , Bohnsack John F. , Wise Carol A. , Punaro Marilynn , Rosé Carlos D. , Pajewski Nicholas M. , Spigarelli Michael , Keddache Mehdi , Wagner Michael , Langefeld Carl D. , Glass David N. 
Published: February 2012

AbstractObjectiveIn a genome‐wide association study of Caucasian patients with juvenile idiopathic arthritis (JIA), we have previously described findings limited to autoimmunity loci shared by JIA and other diseases. The present study was undertaken to identify novel JIA‐predisposing loci using genome‐wide approaches.MethodsThe discovery cohort consisted of Caucasian JIA cases (n = 814) and local controls (n = 658) genotyped on the Affymetrix Genome‐Wide SNP 6.0 Array, along with 2,400 out‐of‐study controls. In a replication study, we genotyped 10 single‐nucleotide polymorphisms (SNPs) in 1,744 cases and 7,010 controls from the US and Europe.ResultsAnalysis within the discovery cohort provided evidence of associations at 3q13 within C3orf1 and near CD80 (rs4688011) (odds ratio [OR] 1.37, P = 1.88 × 10−6) and at 10q21 near JMJD1C (rs647989 [OR 1.59, P = 6.1 × 10−8], rs12411988 [OR 1.57, P = 1.16 × 10−7], and rs10995450 [OR 1.31, P = 6.74 × 10−5]). Meta‐analysis provided further evidence of association for these 4 SNPs (P = 3.6 × 10−7 for rs4688011, P = 4.33 × 10−5 for rs6479891, P = 2.71 × 10−5 for rs12411988, and P = 5.39 × 10−5 for rs10995450). Gene expression data on 68 JIA cases and 23 local controls showed cis expression quantitative trait locus associations for C3orf1 SNP rs4688011 (P = 0.024 or P = 0.034, depending on the probe set) and JMJD1C SNPs rs6479891 and rs12411988 (P = 0.01 or P = 0.04, depending on the probe set and P = 0.008, respectively). Using a variance component liability model, it was estimated that common SNP variation accounts for approximately one‐third of JIA susceptibility.ConclusionGenetic association results and correlated gene expression findings provide evidence of JIA association at 3q13 and suggest novel genes as plausible candidates in disease pathology.