bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface modification of nylon 6 films treated with an He/O2 atmospheric pressure plasma jet
Authors: Gao Zhiqiang , Sun Jie , Peng Shujing , Yao Lan , Qiu Yiping 
Published: December 2010

AbstractTo investigate the effect of the gas composition of the plasma treatment on the surface modification of an atmospheric pressure plasma jet (APPJ), nylon 6 films were treated with APPJ with pure helium (He), He + 1% oxygen (O2), and He + 2% O2, respectively. Atomic force microscopy showed increased surface roughness, whereas X‐ray photoelectron spectroscopy revealed increased oxygen contents after the plasma treatments. The plasma‐treated samples had lower water contact angles and higher T‐peel strengths than the control. The addition of a small amount of O2 to the He plasma increased the effectiveness of the plasma treatment in the polymer surface modification in terms of surface roughness, surface oxygen content, etching rate, water contact angle, and bonding strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The effects of different silane crosslinking approaches on composites of polyethylene blends and wood flour
Authors: Clemons Craig M. , Sabo Ronald C. , Hirth Kolby C. 
Published: December 2010

AbstractThough silane chemistry has been used to crosslink unfilled polyethylene for many years, such crosslinking has only been recently applied to wood plastic composites to improve properties such as creep resistance. However, the presence of wood significantly changes the silane chemistry and a greater understanding is necessary for optimal processing and performance. We investigated three different approaches of adding silane and peroxide during reactive extrusion of wood‐plastic composites were investigated and compared to their unfilled counterparts. Up to 2 grams of a 20:1 solution of vinyltrimethoxysilane and dicumyl peroxide by weight were added per 100 grams of plastic. Low density polyethylene, high density polyethylene, and a blend of the two were investigated as matrices in composites containing approximately 25% wood flour. The unfilled plastics crosslinked efficiently and little premature crosslinking occurred during processing. Though only modest improvements in tensile strengths were found in unfilled plastics, the notched Izod impact energy of unfilled HDPE improved nearly 600% when crosslinked. Unlike the unfilled plastics, most of the crosslinking of the composites occurred during processing. This resulted in high viscosities and processing difficulties, negating some of the advantages of a separate crosslinking step and limiting the amount of crosslinking possible. Some reinforcement of the plastics by the wood flour was achieved when sufficient crosslinking solution was added. Adding crosslinking solution also and greatly increased reverse‐notched impact energies. The differences between the approaches for preparing the crosslinked composites appeared to largely be a matter of efficiency in terms of the amount of crosslinking solution required to affect processing and performance. The most efficient approach was a two‐step procedure where the silane was first grafted to the plastic and then wood flour was compounded with the grafted silane in a second step. Published 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Flow behavior in a corotating twin‐screw extruder of pure polymers and blends: Characterization by fluorescence monitoring technique
Authors: Fang Haixia , Mighri Frej , Ajji Abdellah , Cassagnau Philippe , Elkoun Said 
Published: December 2010

AbstractThe objective of this work was to investigate the flow behavior of pure polymers and blends, especially miscible polymer/polymer systems, in a corotating twin‐screw extruder (TSE) using an online fluorescence monitoring device. An immiscible blend was also studied for the sake of comparison. The fluorescence signal was obtained by using synthesized fluorescence tracers added to the melt at very low concentrations. These tracers consisted of two styrene‐maleic anhydride copolymers (SMA) labeled with anthracene. The investigated blends were SMA8 (8 wt % of MA in SMA)/polystyrene (PS), SMA14 (14 wt % of MA in SMA)/styrene acrylonitrile copolymer (SAN), and poly(methyl methacrylate) (PMMA)/ethyl acrylate‐methyl methacrylate copolymer (PMMAEA). The residence time distribution (RTD), the mean residence time (t), the dimensionless variance (σθ2), the Peclet number (Pe) and the fluorescence peak intensity distribution of pure polymers and binary polymer systems were investigated and interpreted in terms of polymers rheological properties. It was observed that polymers presenting higher viscosity or higher pressure showed longer residence time. A difference in behavior was also observed for the RTD of miscible and immiscible blends. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Crystallinity of polyamide 6 staple fibers in the felt structure under simulated paper machine conditions
Authors: Hakala Tomi , Harlin Ali 
Published: December 2010

AbstractPolyamide 6 (PA6) is used in staple fibers and yarns in paper machine press felts due to its good mechanical properties. The crystalline modifications (α and γ forms) and the degree of crystallinity of PA6 can change under stress (compression) and heat (friction), which are present during mechanical dewatering (nip). Here, we investigate the effects of the molecular weight and crystallinity of a polymer on the mechanical properties of PA6 staple fibers such as wear resistance and compaction. The experimental part involves the ageing of felt specimens in a wet pressing simulator. The properties of the felt (air permeability), and the durability and branching of the staple fiber are examined as functions of the wear of a press felt and the crystallinity of the polymer. The changes that take place in the PA6 polymer are investigated using several techniques, and their connection with the properties of a new or aged press felt is discussed. The results indicate that the increase in molecular weight has a beneficial effect on the material's mechanical properties, and our observations also support previous studies on the crystallinity and branching of PA6. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Microwave‐assisted synthesis of polyglycerol from glycerol carbonate
Authors: Iaych Kamal , Dumarçay Stéphane , Fredon Emmanuel , Gérardin Christine , Lemor Alain , Gérardin Philippe 
Published: December 2010

AbstractMicrowave irradiation of glycerol carbonate allows formation of glycidol, which readily polymerizes to form polyglycerol under mild conditions comparatively to the classical polyetherification reaction involving high temperature and basic conditions. Analysis of the crude reactional mixture indicated the presence of low‐molecular weight oligomers constituted mainly of di, tri, and tetraglycerols with small quantities of higher molecular weights oligomers. Molecular size distribution was relatively similar to that of polyglycerols obtained under basic condition, even if these latter contained slightly higher amounts of high‐molecular weight oligomers. Structure of oligomers differs slightly according to the conditions of polymerization, and polyglycerols are obtained under microwave activation containing higher contents of cyclic isomers, whereas polyglycerols obtained under basic conditions contain more ramified isomers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of compounding sequence on the morphology of organoclay‐filled PA6/PP/MAPP blends
Authors: Wang Li , Guo Zhao‐Xia , Yu Jian 
Published: December 2010

AbstractFour types of compounding sequences were utilized to prepare organoclay‐filled polyamide 6 (PA6)/polypropylene (PP)/maleic anhydride grafted PP (MAPP) blends. The amount of PA6 molecules grafted to MAPP during in situ compatibilization reaction and the distribution ratio of organoclay in the continuous phase and interface zone were determined quantitatively. The relationship among dispersion and distribution states of organoclay, the amount of PA6 grafted to MAPP as well as the deformation, breakup and coalescence of dispersed droplets was elucidated to interpret the difference in phase morphology. Crystallization behavior and dynamic mechanical properties were also investigated and correlated with the morphology of the materials. It has been shown that the PA6/organoclay masterbatch approach results in the smallest average domain size because of the best organoclay dispersion, the highest amounts of PA6 grafted to MAPP, and organoclay at the interface, which efficiently stabilizes the droplets and prevents coalescence of the droplets. The material prepared by this approach has the biggest improvement in dynamic storage modulus. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Star‐shape poly(acrylic acid)‐composed glass‐ionomer cements: Effects of MW and arm number on mechanical properties
Authors: Zhao Jun , Weng Yiming , Xie Dong 
Published: December 2010

AbstractThis study reports the synthesis and characterization of the star‐shape poly(acrylic acid)s with different arm numbers and molecular weight (MW)s. The effects of arm number and initiator concentration on the atom‐transfer radical polymerization reaction kinetics and solution viscosity were studied. The effects of MW and arm number on mechanical properties were evaluated. The results showed that both arm number and MW had significant impacts on the polymerization kinetics, solution viscosity, mechanical strengths, and wear‐resistance. Decreasing arm number and increasing initiator concentration increased the reaction rate. Increasing arm number and initiator concentration decreased the solution viscosity. Decreasing arm number and increasing MW increased mechanical strengths and wear‐resistance. Within the limitations of this study, the experimental cement was 28% in compressive strength, 48% in compressive modulus, 39% in diametral tensile strength, 60% in flexural strength, and 62% in Knoop hardness higher but 19% in fracture toughness lower than commercial Fuji II LC cement. The abrasion and attrition of the experimental cement were only 1.3% and 9.5% of Fuji II LC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Inverted emulsion polymerization route to polyaniline‐3D nanofiber network using sulfonated‐p‐cresol as novel dopant
Authors: Saravanan Chandrasekar , Palaniappan Srinivasan , Akhila Valaboju , Madhavendra Sunkara Sakunthala , Bangal Prakriti Ranjan 
Published: December 2010

AbstractSulfonated‐p‐cresol (SPC) was used as novel dopant for the first time in the synthesis of polyaniline in 3D nanofiber networks (PANI‐3D). Polyaniline in 3D nanofiber network was prepared using organic solvent soluble benzoyl peroxide as oxidizing agent in presence of SPC and sodium lauryl sulfate (SLS) surfactant via inverted emulsion polymerization pathway. The influence of synthesis conditions such as the concentration of the reactants, stirring/static condition, and temperature etc., on the properties and formation of polyaniline nanofiber network were investigated. Polyaniline in 3D nanofiber network with 40–160 nm (diameter), high yield (134 wt % with respect to aniline used), and reasonably good conductivity (0.1 S/cm) was obtained in 24 h time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Antifungal activity of chitosan against Fusarium oxysporum f. sp. cubense
Authors: Al‐Hetar M. Y. , Zainal Abidin M. A. , Sariah M. , Wong M. Y. 
Published: December 2010

AbstractThe in vitro antifungal activity of chitosan against Fusarium oxysporum f. sp. cubense Race 4 (FocR4) the causal agent of banana wilt was investigated. Chitosan at all concentrations tested reduced the hyphal growth of FocR4 on potato dextrose agar media and recording maximum inhibition of 76.36% at 8 mg/mL. The inhibitory effect was found to increase as chitosan concentration increases. The 50% effective concentration value was estimated by probit analysis, and it was 1.4 mg/mL. Chitosan was more effective in potato dextrose broth where it completely inhibited the mycelial growth of FocR4 at all concentrations tested. Chitosan inhibited the sporulation of FocR4 by a maximum of 96.53% at 8 mg/mL chitosan, and 100% inhibition for spore germination was recorded at all concentrations tested. Chitosan at concentrations of more than 1.6 mg/mL was also found to induce morphological changes in FocR4 characterized by agglomeration of hyphae, abnormal shapes, vesicles, or empty cells devoid of cytoplasm in the mycelia. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Novel amphiphilic dextran copolymers nanoparticles for delivery of doxorubicin
Authors: Gao Hongxia , Li Mingjun , Wu Yan 
Published: December 2010

AbstractIn this work, a novel biodegradable amphiphilic copolymer based on dextran and 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphoethanolamine (DPPE) was successfully prepared. The amphiphilic copolymer may self‐assemble into polymeric micelles in an aqueous solution. Fluorescence spectroscopy, dynamic light scattering (DLS), and a transmission electron microscope (TEM) method confirmed the formation of copolymeric micelles. To estimate the feasibility as novel drug carriers, doxorubicin (DOX) was incorporated into polymeric nanoparticles. The DOX‐loaded nanoparticles exhibited greater antitumor effect than free DOX for HeLa celles, suggesting that the dextran/DPPE nanoparticles have great potential as a tumor targeting drug carrier. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
UV aging resistance properties of PBO fiber coated with nano‐ZnO hybrid sizing
Authors: Zhang Chun‐Hua , Huang Yu‐Dong , Yuan Wen‐Jing , Zhang Jian‐Nan 
Published: December 2010

AbstractIn this article, we focus on the ultraviolet (UV) shielding efficiency for poly(p‐phenylene‐2,6‐benzobisoxazole) (PBO) fiber with zinc oxide (ZnO) nanoparticle/epoxy hybrid coating. ZnO nano particles were initially functionalized with silicon coupling agent for improving their dispersion and surface reactivity, and then they were hybridized with epoxy resin by grafting on the ZnO nano particles. The hybrid reactions have been indicated by means of Fourier transform infrared spectrometer (FT‐IR). Its UV light shielding effect of the hybrid coating on PBO fiber properties has been studied using ultraviolet spectrum, tensile test, atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy (XPS). Results showed that the surface topographic, the surface polymer structure, and the tensile strength of coated PBO fiber were less declined than that of uncoated fiber by UV light. From these results, the nano‐ZnO hybrid sizing had good UV‐aging shielding efficiency for PBO fiber. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Improvement of the photostabilization of PVC films in the presence of 2N‐salicylidene‐5‐(substituted)‐1,3, 4‐thiadiazole
Authors: Yousif Emad , Salih Nadia , Salimon Jumat 
Published: December 2010

AbstractThe photostabilization of poly(vinyl chloride) (PVC) films by 2N‐salicylidene‐5‐(substituted)‐1,3,4‐thiadiazole compounds was investigated. The PVC films containing concentration of complexes 0.5% by weight were produced by the casting method from tetrahydrofuran (THF) solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene, and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also tracked (using THF as a solvent). The quantum yield of the chain scission (ϕcs) of these complexes in PVC films was evaluated and found to range between 4.72 × 10−8 and 8.99 × 10−8. Results obtained showed that the rate of photostabilization of PVC in the presence of the additive followed the trend:

According to the experimental results obtained, several mechanisms were suggested depending on the structure of the additive. Among them, UV absorption, peroxide decomposer, and radical scavenger for photostabilizer mechanisms were suggested. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation and biodegradation of hydroxyl terminated poly(fumaric acid‐co‐diethylene glycol) and its segmented polyurethane
Authors: Yang Qun , Shao Fen‐Juan , Lu Da‐Nian , Kimura Yoshiharu 
Published: December 2010

AbstractHydroxyl terminated poly(fumaric acid‐co‐diethylene glycol), poly(FA‐co‐DEG) was prepared by melt polycondensation. The resultant unsaturated aliphatic polyester was characterized by Fourier transform infrared (FTIR) spectroscopy, hydroxyl value, acid value, and intrinsic viscosity. Its enzymatic degradation and crosslinking behavior as well as the effect of crosslinking degree on enzymatic degradation were also investigated. The crosslinking degree and reduction of carbon–carbon double bonds revealed excellent self‐crosslinking nature of poly(FA‐co‐DEG) at high temperature. The results of enzymatic degradation showed that poly(FA‐co‐DEG) has excellent biodegradability and that the biodegradation can be controlled by the crosslinking degree. Polyurethane was prepared by the reaction of poly(FA‐co‐DEG), 2,4‐toluene diisocyanate (TDI), and 1,4‐butanediol (BD). It was found that the biodegradation of the obtained polyurethane was slower than that of the original unsaturated aliphatic polyester poly(FA‐co‐DEG). The peeling strength of the polyurethane was very high, supporting better adhesion property with enhanced crosslinking. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Properties of polystyrene/organically modified layered double hydroxide nanocomposites synthesized by solvent blending method
Authors: Sahu Balakrushna , Pugazhenthi G. 
Published: December 2010

AbstractIn this work, organically modified layered double hydroxides (OLDHs) were prepared and used to make exfoliated polystyrene (PS) nanocomposites by solvent blending method. First, Mg‐Al, Co‐Al, Ni‐Al, Cu‐Al, Cu‐Fe, and Cu‐Cr LDHs were synthesized by coprecipitation method at constant pH using their nitrate salts. The organically modified LDHs (OLDHs) were synthesized using sodium dodecyl sulfate (SDS). Then, PS nanocomposites containing 5 wt % of the above modified LDHs were developed by solvent blending method. The structural and thermal properties of LDHs and their corresponding nanocomposites were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), FTIR spectroscopy, and thermogravimetric analysis (TGA). The formation of exfoliated PS/OLDH nanocomposites is demonstrated by XRD and TEM analysis. TEM analysis also confirms the nanoscale dispersion of the LDH layers in the PS matrix. The presence of sulfate groups in the modified LDHs is confirmed by FTIR spectroscopy. The entire PS/OLDH nanocomposites exhibit enhanced thermal stability relative to pure PS. When 50% weight loss is selected as point of comparison, the decomposition temperature of the nanocomposites is about 5–13°C higher than that of pure PS. Water uptake of the PS nanocomposites is found to be less when compared to pure PS. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis, Structural Characterization, and Reactivity of Group 4 Metallacarboranes Bearing the Ligand [H2C(C5Me4)(C2B9H10)]3−
Authors: Liu Dongmei , Shen Hao , Wang Yaorong , Cai Yuepeng , Xie Zuowei 
Published: December 2010

AbstractA new organic–inorganic hybrid ligand H2C(C5Me4H)(C2B10H11) (2) has been prepared. A selective deboration reaction with piperidine in ethanol resulted in the isolation of [Me3NH][H2C(C5Me4H)(C2B9H11)] (3). An amine‐elimination reaction of 3 with [Zr(NMe2)4] produced a neutral metal‐amide complex [η5:η5‐H2C(C5Me4)(C2B9H10)]Zr(NMe2)(NHMe2) (4). The double‐ring‐opening reaction of 4 with tetrahydrofuran (THF) afforded [η5:η5‐H2C(C5Me4)(C2B9H10)]Zr (OCH2CH2CH2CH2)2N(CH3)2 (5). Treatment of the trianionic salt of 3 with [MCl4(thf)2] gave complexes [{η5:η5‐H2C(C5Me4)(C2B9H10)}M(μ‐Cl)2][Li(thf)2] (M=Zr (6), Hf (7)). Reaction of 6 with LiCH2TMS generated the ionic species [{η5:η5‐H2C(C5Me4)(C2B9H10)}Zr(CH2TMS)2][Li(thf)3] (9). Interaction of complex 6 with KCH2(NMe2)‐o‐C6H4 led to the formation of the neutral metal alkyl complex [η5:η5‐H2C(C5Me4)(C2B9H10)]Zr[σ:σ‐CH2(NMe2)‐o‐C6H4] (10). All complexes have been fully characterized by various spectroscopic techniques and elemental analyses. Some were further confirmed by single‐crystal X‐ray analyses.
Zum Einfluss baulicher Randbedingungen auf das dynamische Verhalten von WIB‐Eisenbahnbrücken
Authors: Rauert Tim , Bigelow Hetty , Hoffmeister Benno , Feldmann Markus , Patz Rüdiger , Lippert Peter 
Published: December 2010

AbstractDie Weiterentwicklung des europäischen Eisenbahnnetzes ist unter anderem durch den vermehrten Einsatz von Hochgeschwindigkeitszügen und eine signifikante Anhebung der Betriebsgeschwindigkeiten gekennzeichnet. Um die Auswirkungen von Zugbeanspruchungen auf Eisenbahnbrücken im Rahmen einer dynamischen Bemessung hinreichend genau vorhersagen zu können, ist die Kenntnis der wesentlichen dynamischen Systemeigenschaften erforderlich. Nur so können bemessungsrelevante Resonanzeffekte, die bei hohen Geschwindigkeiten grundsätzlich nicht auszuschließen sind, rechnerisch auf zuverlässige Weise erfasst werden. Messungen insbesondere an WIB‐Überbauten zeigen jedoch, dass eine realistische rechnerische Abschätzung von Brückeneigenfrequenzen schwierig ist. Tatsächliche und rechnerische Werte weichen in vielen Fällen erheblich voneinander ab. Als ursächlich wird hierfür unter anderem eine unzureichende Berücksichtigung baulicher Randbedingungen angesehen, die teilweise erheblichen Einfluss auf die Steifigkeits‐ und Dämpfungseigenschaften der Brücke haben. Der erste Teil des Beitrags führte in die Problematik ein und präsentierte Ergebnisse aus Messuntersuchungen an WIB‐Brücken. Im vorliegenden zweiten Teil des Beitrags wird nun auf Grundlage numerischer Studien gezeigt, wie sich bauliche Randbedingungen auf das dynamische Verhalten von WIB‐Überbauten auswirken. Abschließend werden die Untersuchungsergebnisse dazu genutzt, Vorschläge für eine genauere dynamische Bemessung abzuleiten.On the influence of constructional elements on the dynamic behaviour of filler beam railway bridges. Enhancements of the European railway system are amongst other things mainly characterized by increased usage of high speed trains and significantly raised operating speeds. To predict effects of train loading on railway bridges for a dynamic design adequately, knowledge of the system’s significant dynamic characteristics is required. Only this ensures that resonance effects, which generally cannot be screened out for high speeds, can be covered analytically by reliable values. Measurements especially carried out on filler beam bridges have shown though that a realistic estimation of eigenfrequencies of bridges is difficult. Actual values and measured ones differ significantly in many cases. In particular non‐consideration of structural constraints is seen as reason for this, given that they have an immense effect on a bridge’s stiffness and damping characteristics. The first part of the contribution gave a brief survey on the dynamics of high‐speed railway bridges. Furthermore results from measurements on filler beam railway decks were presented. In this second part of the contribution the influence of particular constructional elements on the dynamic behaviour of filler beam bridges is investigated, supported by numerical studies. Finally the main outcomes are discussed and proposals for an improved dynamic bridge design are made.