bluuebunny/crossref_metadata_2025_split huggingface dataset:
Waterborne cationomer polyurethane coatings with improved hydrophobic properties
Authors: Król Piotr , Król Bożena , Stagraczyński Ryszard , Skrzypiec Krzysztof 
Published: May 2012

AbstractThe AFM method was used to investigate the phase structure of the coatings, which have been obtained after application of polyurethane cationomers, synthesized in the reaction of 4,4′‐methylenebis(phenyl isocyanate) or isophorone diisocyanate with polyoxyethylene glycol (M = 600) and N‐methyl or N‐butyldiethanolamine with 2,2,3,3‐tetrafluoro‐1,4‐butanediol. Changes were discussed in the surface‐free energy (SFE) and its components, as calculated independently according to the method suggested by van Owens–Wendt, in relation to chemical structures of cationomers, as well as morphology of coating surfaces obtained from those cationomers. Fluorine incorporated into cationomers (about 2–5%) contributed to lower SFE values, down to about 30 mJ/m2. An attempt was made to use 1H‐NMR spectroscopy to provide more extensive grounds for the effect of polyurethane chemical structures (by parameters κ) on the SFE of coatings obtained from such polyurethanes, with the values of SFE (γS, γ) and determined by the Owens–Wendt method. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and investigation of the β‐nucleated polypropylene/polystyrene blends
Authors: Zhang Zishou , Wang Chunguang , Du Yifei , Zhang Junping , Mai Kancheng 
Published: May 2012

AbstractIn this work, β‐polypropylene/polystyrene (β‐PP/PS) blends were prepared with PP, PS, and a novel supported β‐nucleating agent or β‐nucleated PP and PS. The β‐PP/PS blends were compatabilized by PP‐g‐MA, PP‐g‐GMA, POE‐g‐MA, and EVA‐g‐MA, respectively. For exploring the effect of PS amount and compatibilizers on the β‐nucleation of PP, crystallization behavior and melting characteristics, the β‐crystal content and crystal morphology of β‐PP are characterized by differential scanning calorimetry (DSC), wide angle X‐ray diffraction (WAXD), and polarized light microscopy (POM). The results indicated that the PP with high content of β‐crystal was obtained by addition of CaCO3 supported β‐nucleating agent (β‐NA) into PP. The β‐nucleation, crystallization behavior, and melting characteristics, and the β‐crystal content of β‐PP in these blends were not influenced by addition of PS and its amount. However, the increased content of PS decreased the size of β‐spherulites of PP in these blends. The β‐nucleation of PP in compatabilized blends slightly depended on the compatibilizers. β‐PP/PS blends with high β‐crystal content can easily be prepared. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Creep behavior of PLA‐based biodegradable plastic exposed to a hydrocarbon liquid
Authors: Widiastuti Indah , Sbarski Igor , Masood S.H. 
Published: May 2012

AbstractThis study explores the effect of hydrocarbon liquid on creep behavior of polylactic acid (PLA)‐based plastic. Evolution of the mechanical properties of the material was investigated experimentally by measurement of creep under tensile load. Tensile creep behavior was studied with a constant load over a temperature range from 30 to 50°C using specimens containing different levels of liquid. It was shown that the hydrocarbon liquid diffusion obeys the Fickian law of diffusion. The viscoelastic properties vary with temperature and these properties dramatically decrease above the glass transition temperature (Tg). Significant decreases in modulus and in the peak of tan δ were observed with an increase in liquid concentration at low temperatures. In contrast, at high temperatures, drier material recorded lower storage modulus. However, only small changes ofTgwere recorded. Dependence of compliance on temperature was observed in the creep test at all levels of liquid content. With respect to drier samples, it was noted that the high liquid content material had a lower rate of increasing creep strain with temperature. Therefore, at elevated temperatures, higher creep strain of dry specimens was observed compared to those with a higher liquid content. The improvement of creep resistance and stiffening of material at high temperatures can be attributed to the significant increase of crystallinity fraction induced by liquid absorption. Understanding the effect of liquid diffusion in conjunction with temperature provides useful information for assessment of the potential use of this biodegradable plastic in load‐bearing applications exposed to an organic liquid. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of surface modifiers and surface modification methods on properties of acrylonitrile–butadiene–styrene/poly(methyl methacrylate)/nano‐calcium carbonate composites
Authors: Zhang Aimin , Zhao Guoqun , Guan Yanjin 
Published: May 2012

AbstractNano‐calcium carbonate (nano‐CaCO3) was used in this article to fill acrylonitrile–butadiene–styrene (ABS)/poly(methyl methacrylate) (PMMA), which is often used in rapid heat cycle molding process (RHCM). To achieve better adhesion between nano‐CaCO3 and ABS/PMMA, nano‐CaCO3 particles were modified by using titanate coupling agent, aluminum–titanium compound coupling agent, and stearic acid. Dry and solution methods were both utilized in the surface modification process. ABS/PMMA/nano‐CaCO3 composites were prepared in a corotating twin screw extruder. Influence of surface modifiers and surface modification methods on mechanical and flow properties of composites was analyzed. The results showed that collaborative use of aluminum–titanium compound coupling agent and stearic acid for nano‐CaCO3 surface modification is optimal in ABS/PMMA/nano‐CaCO3 composites. Coupling agent can increase the melt flow index (MFI) and tensile yield strength of ABS/PMMA/nano‐CaCO3 composites. The Izod impact strength of composites increases with the addition of titanate coupling agent up to 1 wt %, thereafter the Izod impact strength shows a decrease. The interfacial adhesion between nano‐CaCO3 and ABS/PMMA is stronger by using solution method. But the dispersion uniformity of nano‐CaCO3 modified by solution method is worse. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Highly sensitive toluene vapor sensors using carbon black/amino‐functional copolymer composites
Authors: Matsuguchi Masanobu , Asahara Koji , Mizukami Takashi 
Published: May 2012

AbstractAn amino‐functional copolymer [N,N,‐dimethyl‐1,3‐propanediamine (MCD)] developed in our laboratory was blended with carbon black (CB/MCD composite) and its electrical responses to toluene vapor at low concentrations were measured at 30°C. When exposed to 200 ppm of toluene vapor, the CB/MCD sensor responded at S = 0.04 (S was obtained by dividing the relative change in the resistance of the sensor upon exposure to toluene vapor by the baseline resistance), demonstrating its ability to detect toluene vapor at low concentrations. The response was affected by humidity in the atmosphere due to the hydrophilic nature of MCD film; however, the behavior was reproducible before and after exposure of the sensor to the humid atmosphere. In addition, in 10 consecutive sorbing/desorbing cycles, it was confirmed that the changes in the resistance of the CB/MCD sensor were reproducible. These favorable sensing characteristics were attributed to vapor sorption behavior arising from the glassy and loosely crosslinked nature of MCD and explained by the dual‐sorption model. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and characterization of acrylic polymer nanocomposite films obtained from aqueous dispersions
Authors: Carneiro Catarina , Vieira Ricardo , Mendes Adélio M. , Magalhães Fernão D. 
Published: May 2012

AbstractA functionalized fumed silica was dispersed in water using a nonionic surfactant, yielding a stable nanodispersion. This was blended with an aqueous acrylic polymer dispersion to produce hybrid nanocomposite films. The silica particles were shown to be well dispersed in the polymer matrix, with little agglomeration. Further evidence of good compatibility between the silica and acrylic polymer was given by the improved thermal stability of the nanocomposite compared with the pristine polymer. The nanocomposite films exhibited significantly lower dirt pick‐up behavior, which seems to be associated to the nanoroughness of the composite film surface observed in AFM analysis. This decreases the contact area between film and micrometric dirt particles. Surface tension and hardness do not seem to be significantly different in the composite and noncomposite materials. This approach may provide a strategy to obtain hybrid coatings with self‐cleaning properties, taking advantage of the relatively low cost, and large availability of fumed silica. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of end‐capped nanosilica on mechanical properties and microstructure of LLLDPE/EVA blends
Authors: Heidary Mahmud , Jafari Seyed Hassan , Khonakdar Hossein Ali , Wagenknecht Udo , Heinrich Gert , Boldt Regine 
Published: May 2012

AbstractThis article describes the influence of a hexamethyldisilane‐treated nanosilica (end‐capped SiO2) on morphological and tensile properties of linear low‐density polyethylene (LLDPE)/ethylene vinyl acetate copolymer (EVA) blends prepared by one step melt mixing process via a twin screw extruder. The treatment replaces many of the surface hydroxyl groups on the nanosilica with extremely hydrophobic trimethylsilyl groups. Transmission electron microscopic results revealed that the treated nanosilica formed small aggregates in polymer matrix and they were mostly localized in the LLDPE matrix besides localizing in EVA droplets and at LLDPE/EVA interface. These nanoparticles had compatibilizing role on the blend system and at high content changed morphology from biphasic toward a monophasic. Addition of the end‐capped nanosilica to the blend and increasing its content increased the Young's modulus, tensile strength as well as elongation at break of the nanocomposites. Different models were used to predict the Young's modulus of the nanocomposites. It was found that the experimental data were better fitted by Counto model than the other models. Melt rheological investigations on the nanosilica filled LLDPE/EVA blend system showed that incorporation of the treated nanosilica, even up to 10 wt %, did not lead to a solid‐like behavior at low‐frequency indicating ease of processing of such highly filled system. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Structure and property of polyurethane/SiO2 composite elastomer prepared via in situ polymerization
Authors: Ding Jingjing , Ye Lin 
Published: May 2012

AbstractA series of polyurethane (PU)/SiO2 composites were prepared via in situ polymerization through a prepolymer process. The effect of SiO2 content on mechanical and solvent‐resistant properties of PU/SiO2 composites was investigated. It was found that with increasing SiO2 content, the tensile strength and toughness, hardness, and modulus of PU composites increased. PU/SiO2 composites exhibited only one loss peak corresponding to the glass transition temperature of the soft‐segment of PU, which shifted insignificantly with increasing SiO2 content. The equilibrium swelling ratio and swelling rate constant in cyclohexanone and xylene were reduced by increasing SiO2 content, indicating the enhancement of the solvent resistance of the PU elastomer. Morphology observation of PU/SiO2 composites showed that the acicular SiO2 dispersed uniformly in PU matrix, and there was no obvious aggregation even at 9 wt % loading of SiO2. The reinforcing and toughening effects depended largely on the dispersion of SiO2 in PU matrix and the interfacial layer formed between the two phases. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and characterization of polyethylene/silver nanocomposite films with antibacterial activity
Authors: Dehnavi Arefeh Sadat , Aroujalian Abdolreza , Raisi Ahmadreza , Fazel Shahrzad 
Published: May 2012

AbstractIn this work, a novel method was proposed for the fabrication of antibacterial nanocomposite polymeric films, for use in food packaging. In the first step, a stable colloidal solution of silver nanoparticles was prepared by chemical reduction of silver salt using fructose as an environmental friendly reducing agent. In the second step, corona air plasma was used as a pretreatment of low density polyethylene (LDPE) films to increase the adhesion of silver nanoparticles on the film surface. In the third step, silver nanoparticles were coated on the LDPE surface by immersion of the treated films in the colloidal silver solutions. Surface morphology of the silver/LDPE nanocomposite was characterized by FE‐SEM and AFM analysis. The amounts of coated silver and silver ion release from the nanocomposite surface were determined. In addition, the antibacterial activity of the fabricated films was evaluated by agar well diffusion and dynamic shake flask methods. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Tripodal “click” ligands for copper‐catalyzed ATRP
Authors: Sangtrirutnugul Preeyanuch , Maisopa Purmpoon , Chaicharoenwimolkul Laksamee , Sunsin Atchariya , Somsook Ekasith , Reutrakul Vichai 
Published: May 2012

AbstractA series of tris(R‐methyltriazolylmethyl)amines [R = C6H5 (1), 4‐FC6H4 (2), 4‐MeOC6H4 (3), Fc (4)] were prepared and used as ligands for catalytic ATRP of methyl methacrylate (MMA). Despite a lower activity, the CuBr/4 catalyst promoted relatively well controlled polymerization compared to CuBr/1, as evidenced by narrower polydispersity indices. Meanwhile, no polymerization activity was observed with CuBr/2 and CuBr/3 under the catalytic conditions investigated. The CV measurements of CuBr2 complexes supported 1 and 4 in DMSO showed E1/2 values of –0.206 and –0.224 V, respectively, confirming the more electron‐rich nature of CuBr/4. Although both CuBr/1 and CuBr/4 catalysts were only partially soluble in several organic solvents used, kinetic studies revealed a pseudo first order linear plot of ln[M]0/[M]t versus time. Addition of CuBr2 into the polymerization systems led to a decrease in polymer polydispersities and the observed rate constants (kobs). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Poly(N‐hydroxyethyl acrylamide)‐b‐polystyrene by combination of ATRP and aminolysis processes
Authors: Gunes Deniz , Batu Kurtarel Omer , Bicak Niyazi 
Published: May 2012

AbstractBlock copolymers of very hydrophilic poly(N‐hydroxyethyl acrylamide) (PHEAA) with polystyrene (PS) were successfully synthesized by sequential atom transfer radical polymerization of ethyl acrylate (EA) and styrene monomers and subsequent aminolysis of the acrylic block with ethanolamine. Quantitative aminolysis of poly(ethyl acrylate) (PEA) block yielded poly(N‐hydroxyethyl acrylamide)‐b‐polystyrene in well‐defined structures, as evidenced by Fourier transform infrared spectroscopy (FTIR) and 1H‐NMR spectroscopy techniques. Three copolymers with constant chain length of PHEAA (degree of polymerization: 80) and PS blocks with 21, 74, and 121 repeating units were prepared by this method. Among those, the block copolymer with 21 styrene repeating units showed excellent micellation behavior in water without phase inversion below 100°C, as inferred from dynamical light scattering, environmental scanning electron microscopy, and fluorescence measurements. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Molecular composites obtained by polyaniline synthesis in the presence of p‐octasulfonated calixarene macrocycle
Authors: Grigoras Mircea , Catargiu Ana Maria , Tudorache Florin 
Published: May 2012

AbstractPolyaniline (PANI) molecular composites were synthesized by chemical oxidative polymerization of the aniline and aniline dimer, N‐phenyl‐1,4‐phenylendiamine, in the presence of a macrocycle, calix[8]arene p‐octasulfonic acid (C8S), using ammonium peroxidisulfate as oxidant. The macrocycle has acted both as acid dopant and surfactant to obtain processable PANI‐ES. The PANI/calix[8]arene p‐octasulfonic acid composite was also obtained by a simple doping of PANI emeraldine base form with calix[8]arene sulfonic acid. The structure of materials was confirmed by Fourier transform infrared, UV–vis and nuclear magnetic resonance spectroscopy. All synthesized composite materials are amorphous and soluble in chloroform, dimethylsulfoxide, NMP, showing excellent solution‐processing properties combined with electrical conductivity. Cyclic voltammetry evidenced a good electroactivity for the composite films. Dielectric properties (dielectric constant and dielectric losses) were determined and are comparable with those of other PANI/ionic acid polymer composites. Preliminary studies have evidenced a high dielectric constant (104 at 100 Hz) and electrical conductivity of 6 × 10−3 S/cm for PANI composites. From sulfur elemental analysis of the PANI/calixarene, it results that the content in macrocycle is ∼30% (weight). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Dye removal from colored‐textile wastewater using chitosan‐PPI dendrimer hybrid as a biopolymer: Optimization, kinetic, and isotherm studies
Authors: Sadeghi‐Kiakhani Mousa , Arami Mokhtar , Gharanjig Kamaladin 
Published: May 2012

AbstractPreparation of a biopolymer chitosan‐polypropylene imine (CS‐PPI) as a biocompatible adsorbent and its reactive textile dyes removal potential were performed. Chemical specifications of CS‐PPI were determined using Fourier transform infrared, 1H‐NMR, and 13C‐NMR. The surface morphology of the CS‐PPI surface was characterized by scanning electron microscopy. Results confirmed that the linkages between the NH2 groups of PPI dendrimer and carboxylic groups of modified Chitosan were accomplished chemically. Two textile reactive dyes, reactive black 5 (RB5) and reactive red 198 (RR198), were used as model compounds. A response surface methodology was applied to estimate the simple and combined effects of the operating variables, including pH, dye concentration, time contact, and temperature. Under the optimal values of process parameters, the dye removal performance of 97 and 99% was achieved for RB5 and RR198, respectively. Furthermore, the isotherm and kinetic models of dyes adsorption were performed. Adsorption data represented that both examined dye followed the Langmuir isotherm. The adsorption kinetics of both reactive dyes were satisfied by pseudo‐second order equation. Based on this study, CS‐PPI due to having high adsorption capacity (6250 mg/g for RB5 and 5882.35 mg/g for RR198), biocompatibility and ecofriendly properties might be a suitable adsorbent for removal of reactive dyes from colored solutions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The effect of multiple variables on tensile property of injection‐molded polypropylene through the combination of orthogonal design and variance analysis
Authors: Hu Juan , Gao Xueqin , Chen Zhanchun , Shen Kaizhi , Deng Cong 
Published: May 2012

AbstractIn this article, a combination of orthogonal design and variance analysis was used to study the systematical effect of vibration pressure, melt temperature, packing cycle, and mold temperature on the tensile property of polypropylene in dynamic packing injection molding (DPIM). The tensile measurement results show that all variables had significant influence on the final tensile property under the present molding condition. Meanwhile, the optimal molding condition to achieve high tensile strength was also obtained in the investigated ranges. Further quantitative statistical analysis revealed the degree of influence of four variables on the tensile property of polypropylene in DPIM. The sequence of the degree of influence from maximum to minimum is as follow: vibration pressure, melt temperature, packing cycle, and mold temperature. These findings provide the experimental and statistical evidences to illustrate that the application of orthogonal design and variance analysis might be an effective approach to systematically study the effect of multiple variables on the final mechanical property. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Controller Synthesis with Highly Simplified Linear Constraints
Authors: Dideban Abbas , Zareiee Meysam , Alla Hassane 
Published: May 2012

AbstractThis paper deals with the problem of forbidden states in safe Petri nets to obtain a maximally permissive controller. To prevent the system from entering the forbidden states, assigning some constraints to them is possible. The constraints can be enforced on the system using control places. When the number of forbidden states is large, a large number of constraints should be assigned to them. This results in a large number of control places being added to the model of the system, which causes a complicated model. Some methods have been proposed to reduce the number of constraints. Nevertheless, they do not always give the best results. In this paper, two ideas are offered to reduce the number of constraints, giving a more simplified controller.
Massive Human Co‐Expression Network and Its Medical Applications
Authors: Feng Yaping , Hurst Jonathan , Almeida‐De‐Macedo Marcia , Chen Xi , Li Ling , Ransom Nick , Wurtele Eve Syrkin 
Published: May 2012

AbstractNetwork‐based analysis is indispensable in analyzing high‐throughput biological data. Based on the assumption that the variation of gene interactions under given biological conditions could be better interpreted in the context of a large‐scale and wide variety of developmental, tissue, and disease conditions, we leverage the large quantity of publicly available transcriptomic data >40,000 HG U133A Affymetrix microarray chips stored in ArrayExpress (http://www.ebi.ac.uk/arrayexpress/) using MetaOmGraph (http://metnet.vrac.iastate.edu/MetNet_MetaOmGraph.htm). From this data, 18,637 chips encompassing over 500 experiments containing high‐quality data (18637 Hu‐dataset) were used to create a globally stable gene co‐expression network (18637 Hu‐co‐expression‐network). Regulons, groups of highly and consistently co‐expressed genes, were obtained by partitioning the 18637 Hu‐co‐expression‐network using an Markov clustering algorithm (MCL). The regulons were demonstrated to be statistically significant using a gene ontology (GO) term overrepresentation test combined with evaluation of the effects of gene permutations. The regulons include ca. 12% of human genes, interconnected by 31,471 correlations. All network data and metadata are publically available (http://metnet.vrac.iastate.edu/MetNet_MetaOmGraph.htm). Text mining of these metadata, GO term overrepresentation analysis, and statistical analysis of transcriptomic experiments across multiple environmental, tissue, and disease conditions, has revealed novel fingerprints distinguishing central nervous system (CNS)‐related conditions. This study demonstrates the value of mega‐scale network‐based analysis for biologists to further refine transcriptomic data, derived from a particular condition, to study the global relationships between genes and diseases, and to develop hypotheses that can inform future research.