bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental study of preform reheat temperature in two‐stage injection stretch blow molding
Authors: Demirel B. , Daver F. 
Published: September 2012

AbstractPlastic bottles used for carbonated soft drink (CSD) packages are most commonly made from poly(ethylene terephthalate) (PET) by injection stretch blow molding (ISBM). The required bottle performance criteria vary with its application but typically include top‐load strength, burst strength, optical clarity, thermal stability, and barrier properties. An experimental study of the preform reheat temperature was carried out for a 1.5‐l PET bottle produced by a two‐stage ISBM machine. The overall temperature of the preform was changed by controlling the reheat temperature of the preform; all the other process variables and preform dimensions were kept constant. Performance of the PET bottles for differing preform reheat temperatures was measured experimentally in terms of top‐load strength, burst pressure resistance, environmental stress cracking resistance (ESCR), and thermal stability. It was observed that the ESCR values and the burst strength decreased with the increasing reheat temperature, whereas the top‐load strength increased. Thermal stability tests confirmed that high‐preform reheat temperatures had a detrimental effect on the self‐standing feature of the bottles. Decreasing the reheat temperature as low as possible, while maintaining a certain preform temperature profile, ensured high ESCR and burst strength values and prevented the concaveness at the bottom of the bottle. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Study of morphology, mechanical properties, and thermal behavior of green aliphatic–aromatic copolyester/bamboo flour composites
Authors: Adhikari Rameshwar , Bhandari Netra Lal , Causin Valerio , Le Hai H. , Radusch Hans‐Joachim , Michler Goerg H. , Saiter Jean Marc 
Published: September 2012

AbstractAiming at development of completely biodegradable composite materials based on locally available low‐cost bamboo flour (BF) as filler, structure properties correlations in aliphatic–aromatic copolyester/BF composites fabricated by melt mixing have been studied by means of different techniques such as electron microscopy, X‐ray diffraction, tensile testing, and thermogravimetric analysis (TGA). It has been demonstrated that the BF can be successfully incorporated homogeneously into the biodegradable polymeric matrix up to high content. The filler weakly adheres to the matrix as demonstrated by the pulling up of bamboo fibers on the electron micrographs and further attested by TGA. At high filler concentration, the polymer acts merely as binding material. The semicrystalline framework of the matrix polymer is hindered by the presence of the fibers, the structural changes being more pronounced at the surfaces than in the bulk, which indicates preferential segregation of the fibers toward the specimen surface. This opens new possibilities for a more detailed engineering of materials surfaces. The mechanical properties of the composites are suited for low‐load‐bearing applications. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Dielectric and mechanical properties of natural nanofibers‐reinforced ethylene propylene diene rubber: Carrot foliage and corn gluten
Authors: Rozik Nehad N. , Abd‐El Messieh Salwa L. , Yaseen Attia A. , Shouk Abd‐El‐Hafiz A. 
Published: September 2012

AbstractA study has been carried out to investigate the dielectric and mechanical properties of composites based on reinforcing carrot foliage (CF) and corn gluten meal (CGM) as by‐products of food processing units into ethylene propylene diene rubber matrix. Transmission electron microscope micrographs indicate that both types of fillers are in the nanoscale. The permittivity ε′ and dielectric loss ε″ were measured in the frequency domain and at room temperature ∼ 25°C. The increase in ε′ and ε″ by increasing filler content is due to its reinforcing nature which was found to be more pronounced in case of CF than CGM. The mechanical properties are found to increase in the same manner. The values obtained for ε′ and ε″recommend such composites to be used in the electrical insulation purposes. The analysis of composite morphology indicated that at low concentration both types of fillers are fine distributed in the EPDM matrix, whereas at higher filler loading aggregation of filler is clearly appeared. The composites under investigation are found to be highly thermal aging resistant as both electrical and mechanical properties are slightly affected by such aging. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Contribution of organomodified clay on hybrid microstructures and properties of epoxidized natural rubber‐based nanocomposites
Authors: Chattopadhyay Pijush Kanti , Praveen Srinivasan , Chandra Das Narayan , Chattopadhyay Santanu 
Published: September 2012

AbstractInfluence of organic modifying agent of clay on dispersion, distribution, hybrid microstructure formation, and associated performance properties of epoxidized natural rubber‐based composites was evaluated. Binary and ternary composites of carbon black (CB) and two organomodified layered silicates (i.e., nanomer I30E and Cloisite 30B) were prepared and characterized based on small angle X‐ray scattering, transmission electron microscopy, hydrodynamic swelling, tensile measurement, and dynamic mechanical analyses. Greater extent of exfoliation and “nanounit” formation was noted in ternary composites containing nanomer I30E, which was reflected in higher interfacial roughness (ds = 2.82) and lower radius of gyration (Rg = 205 Å). Morphological observations suggested higher nanomer I30E–CB interactions than that of Cloisite 30B–CB. The interplatelet distance in Cloisite 30B (d = 1.83 nm) stacks was lower than that of nanomer I30E (d = 2.26 nm). These two factors jointly contributed in higher breakdown of nanomer I30E stacks by CB than that of Cloisite 30B stacks. Greater exfoliation and nanounit formation in I30E–CB‐filled nanocomposite was also reflected in increased degree of crosslinking (n = 20 × 10−5%), tensile modulus/strength, half height width of damping peak (20.3°C), and filler effectiveness (C = 0.33). POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Time‐dependent response of polypropylene/clay nanocomposites under tension and retraction
Authors: Drozdov Aleksey D. , Christiansen Jesper deC. 
Published: September 2012

AbstractObservations are reported in relaxation tests under tension and retraction on polypropylene/clay nanocomposites with various contents of filler. A two‐phase constitutive model is developed in cyclic viscoelasticity and viscoplasticity of nanocomposites. Adjustable parameters in the stress–strain relations are found by fitting the observations. Ability of the constitutive equations to describe characteristic features of the time‐dependent behavior of nanocomposites under cyclic deformation is confirmed by numerical simulation. POLYM. ENG. SCI., 2013 © 2012 Society of Plastics Engineers
Synthesis and characterization of copolymer grafted magnetic nanoparticles via surface‐initiated nitroxide‐mediated radical polymerization
Authors: Chen Fang , Cai Zhengwang , Huang Yong , Luo Wenqian , Chen Jiucun 
Published: September 2012

Abstract“Grafting from” surface‐initiated nitroxide‐mediated radical polymerization (SI‐NMRP) techniques were used to synthesize poly[styrene‐co‐(maleic anhydride)] copolymer brushes from the Fe3O4 surfaces. Well‐defined polymer chains were grown from the Fe3O4 surfaces to yield particles with a Fe3O4 core and a polymer outer layer. The observed narrow molecular weight distributions (Mw/Mn), linear kinetic plots and linear plots of molecular weight (Mn) versus conversion for the free polymer indicated that the chain growth from the Fe3O4 surface was a controlled process by adding an excess of 2,2,6,6‐tetramethylpiperidinyloxy (TEMPO). The modified nanoparticles were subjected to detailed characterization using XRD, TEM, FT‐IR, and TGA. The analyses of vibration sample magnetometer (VSM) verified that the nanoparticles owned good magnetic property. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Fabrication and characterization of boron doped yttria‐stabilized zirconia nanofibers
Authors: Tunç Tuncay , Uslu İbrahim 
Published: September 2012

AbstractBoron doped and undoped poly(vinyl) alcohol/zirconium‐yttrium acetate (PVA/Zr‐Y) nanofibers were prepared by electrospinning using PVA as a precursor. The effect of boron doping was investigated in terms of solution properties, morphological changes and thermal properties. The effect of boron doping on calcined yttria stabilized zirconia (YSZ) fibers was evaluated by X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy analysis. XRD analysis revealed varying amounts of monoclinic and tetragonal zirconia present in the undoped fibers calcined at 800°C. The average crystallite sizes of the undoped YSZ were increased from 9.28 to 22.79 nm with calcining temperature increasing from 250 to 800°C. The crystallite size was enhanced with boron doping. The systematic evolution of morphological features in the spun and the processed fibers were employed by scanning electron microscopy. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Mechanical, thermal, barrier, and rheological properties of poly(ether‐block‐amide) elastomer/organoclay nanocomposite prepared by melt blending
Authors: Choi Myung‐Chan , Jung Ji‐Yoen , Yeom Hyun‐Sik , Chang Young‐Wook 
Published: September 2012

AbstractPolyether block amide (PEBA) elastomer‐organoclay nanocomposites were prepared by a melt mixing technique. The X‐ray diffraction and transmission electron microscope analysis indicated that the nanocomposite formed a partially exfoliated nanostructure in which the organoclay was dispersed uniformly throughout the matrix at the nanometer scale. The effect of organoclay on the melting temperature (Tm), glass transition temperature (Tg), crystallization temperature (Tc), and heat of fusion (ΔHm) of the PEBA was determined by differential scanning calorimetry. Enhanced mechanical properties of the nanocomposites were observed from tensile and dynamic mechanical analysis. Thermal gravimetric analysis showed that the clay nanoparticles caused an increase in the thermal stability of the PEBA. Measurement of oxygen permeability and the degree of swelling in ASTM #3 oil indicated that the gas barrier properties and solvent resistance were greatly improved by the clay nanoparticles. Melt rheological studies revealed that the nanocomposites exhibited strong shear thinning behavior and a percolated network of the clay particles was formed. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Supramolecular structure and anomer‐selective formation of polyglucuronic acid
Authors: Stetco I. Alina , Merschrod S Erika F 
Published: September 2012

AbstractPolyglucuronic acids provide a biocompatible matrix for industries ranging from pharmaceuticals to agriculture. Here we provide a method for selectively producing α‐polyglucuronic acid, a simple alternative to the oxidation of cellulose or amylose with 2,2,6,6‐tetramethylpiperidine‐1‐oxyl radical (TEMPO) or isolation from bacterial cultures. Atomic force micrographs show the pH‐dependent formation and persistence of polyglucuronic acid fibrils, while NMR studies demonstrate the selectivity of the glycosidic linkage. By controlling pH, oligoglucuronate chains are created, with both NMR and AFM data showing the preservation of this linkage in basic medium after formation under acid. Clear evidence for the formation of the C–O–C glycosidic bond comes from peaks in the 13C NMR spectra, revealing a linkage through the anomeric carbon atom and also a linkage with a ring carbon atom.
Preparation of O‐diallylammonium chitosan with antibacterial activity and cytocompatibility
Authors: Jou Chi‐Hsiung , Yang Ming‐Chien , Suen Maw‐Cherng , Yen Chien‐Kuo , Hung Chia‐Chun , Hwang Mou‐Chuan 
Published: September 2012

AbstractIn this study, a derivative of chitosan, O‐hydroxy‐2,3‐propyl‐N‐methyl‐N,N‐diallylammonium chitosan methyl sulfate (O‐MDAACS), was synthesized by reacting chitosan with methyl diallyl ammonium. The O‐MDAACS was confirmed by Fourier transform infrared spectroscopy and 1H NMR. Characterization was conducted including X‐ray diffraction, differential scanning calorimetry and thermogravimetry. The antibacterial activities of O‐MDAACS against Staphylococcus aureus and Klebsiella pneumoniae were evaluated. The minimum inhibitory concentrations on O‐MDAACS were 3.7% and 23% of those on chitosan against S. aureus and K. pneumonia, respectively. The minimum bactericidal concentrations on O‐MDAACS were 7% and 36% of those on chitosan against S. aureus and K. pneumonia, respectively. Thus the antibacterial activity of O‐MDAACS was higher than that of chitosan. The cytocompatibility was evaluated in vitro with L929 fibroblasts. The results showed that after 72 h incubation the cell viability on O‐MDAACS was about 12% and 59% higher than those on chitosan and on control, respectively. © 2012 Society of Chemical Industry
Grafting of titanium dioxide microspheres with a temperature‐responsive polymer via surface‐initiated atom transfer radical polymerization without the use of silane coupling agents
Authors: Smirnov Eugene A , Meledina Maria A , Garshev Alexey V , Chelpanov Vitaly I , Frost Sven , Wieneke Jan U , Ulbricht Mathias 
Published: September 2012

AbstractTitania microspheres with narrow size distribution and diameters of about 1 µm were prepared and subsequently functionalized using surface‐initiated atom transfer radical polymerization (ATRP) of N‐isopropylacrylamide. The ATRP initiator was immobilized on the particle surface via acylation of surface hydroxyl groups with α‐bromoisobutyryl bromide. Subsequently, an established ATRP reaction system was used for the preparation of titania surface‐grafted poly(N‐isopropylacrylamide) (PNiPAAm). Characterization was performed with electron microscopies, X‐ray diffraction, infrared spectroscopy and dynamic light scattering. It was found that the particle size in aqueous dispersions changed reversibly with temperature as expected for a shell of PNiPAAm, a polymer with a lower critical solution temperature at 32 °C. This confirmed the successful preparation of functional, stimuli‐responsive TiO2 microparticles via a straightforward controlled surface‐initiated polymerization method.
Morphology and property changes of immiscible polycarbonate/poly(L‐lactide) blends induced by carbon nanotubes
Authors: Wang Yong‐hong , Shi Yun‐yun , Dai Jian , Yang Jing‐hui , Huang Ting , Zhang Nan , Peng Ya , Wang Yong 
Published: September 2012

AbstractBlends of polycarbonate (PC)/poly(l‐lactide) (PLLA) have great potential in applications ranging from packaging materials to consumer electronics. However, research into these blends is relatively limited compared with that into other polyesters. In this work, different contents of functionalized multiwalled carbon nanotubes (FMWCNTs) were introduced into PC/PLLA blends. The crystallization and melting behaviors of the nanocomposites were investigated using differential scanning calorimetry. The morphology of the nanocomposites and the dispersion states of the FMWCNTs were investigated using scanning electron microscopy, transmission electron microscopy and rheological measurements. The results showed that all samples were in the amorphous state during the injection‐molding process. Although the co‐continuous morphology features of samples was not changed, the presence of the FMWCNTs noticeably induced an increase of phase domains of PC, which was suggested to be the result of the formation of a percolated FMWCNT network structure. The electrical resistivity of the nanocomposites was greatly reduced when the content of FMWCNTs was increased to 2 wt%. The determination of mechanical properties showed that the addition of FMWCNTs facilitated an improvement of the fracture resistance. Another exciting aspect of this research was that the hydrolytic degradation ability of the blends was further improved by adding the FMWCNTs.
‘Edge‐light’: combination of sensitive crack detection and luminescence measurements
Authors: Ortner A. , Gräff O. , Stelzl M. , Macherey F. , Neubecker R. 
Published: September 2012

ABSTRACTWe present a measurement technique that we call ‘edge‐light’, which allows a very sensitive detection of cracks in solar wafers and cells. For polycrystalline material, we found to be able to detect much smaller cracks than possible with conventional equipment. The technique is based on dark‐field illumination with the illuminating light entering the wafer (or the cell) from the edges and being kept inside the wafer by total internal reflection. As detector, an infrared line‐scan camera is used, giving high resolution images. In this configuration, even small cracks appear with high contrast, whereas the grain structure is not visible. In the same setup, photoluminescence or electroluminescence can be recorded in the same run in order to gain information on electronic properties. For the case of photoluminescence, only the scan line needs to be irradiated by the optical excitation source. Consequently, the necessary optical power can be lower and/or exposure times can be shorter. The combination of several measurement channels (crack detection, luminescence) with different light/excitation sources and a single camera is achieved by a special application software for an field programmable gate array (FPGA) frame grabber. The integration of the two measurements principles in a single setup allows simultaneous determination of mechanical stability and electronic quality properties. The setup was proven to work under inline conditions. Copyright © 2012 John Wiley & Sons, Ltd.
Binding cellulose and chitosan via click chemistry: Synthesis, characterization, and formation of some hollow tubes
Authors: Peng Pai , Cao Xuefei , Peng Feng , Bian Jing , Xu Feng , Sun Runcang 
Published: September 2012

AbstractA novel cellulose‐click‐chitosan polymer was prepared successfully in three steps: (1) propargyl cellulose with degrees of substitution (DS) from 0.25 to 1.24 was synthesized by etherification of bamboo Phyllostachys bambusoide cellulose with propargyl chloride in DMA/LiCl in the presence of NaH. The regioselectivity of propargylation on anhydrous glucose unit determined by GC‐MS was in the order of 2 >> 6 > 3; (2) the functional azide groups were introduced onto the chitosan chains by reacting chitosan with 4‐azidobenzoic acid in [Amim]Cl/DMF and the DS ranged from 0.02 to 0.46; (3) thus, the cellulose‐click‐chitosan polymer was obtained via click reaction, that is, the Cu(I)‐catalyzed Huisgen 1,3‐dipolar cycloaddition reaction, between the terminal alkyne groups of cellulose and the azide groups on the chitosan backbone at room temperature. The successful binding of cellulose and chitosan was confirmed and characterized by FTIR and CP/MAS 13C NMR spectroscopy. TGA analyses indicated that the cellulose‐click‐chitosan polymer had a higher thermal stability than that of cellulose and chitosan as well as cellulose–chitosan complex. More interestingly, some hollow tubes with near millimeter length were also observed by SEM. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Biodegradable poly(carbonate‐ether)s with thermoresponsive feature at body temperature
Authors: Gu Lin , Gao Yonggang , Qin Yusheng , Chen Xuesi , Wang Xianhong , Wang Fosong 
Published: September 2012

AbstractNovel biodegradable poly(carbonate‐ether)s (PCEs) with lower critical solution temperature (LCST) at body temperature were synthesized by copolymerization of CO2 and ethylene oxide (EO) under double metal cyanide (DMC) catalyst. The PCEs showed carbonate unit (CU) content of 1.0–42.4 mol % and molecular weight of 2.7–247 kg/mol, which exhibited reversible thermoresponsive feature in deionized water with LCST in a broad window from 21.5 to 84.1 °C. The LCST was highly sensitive to the CU content and the molecular weight of PCEs, and it showed a linear relation with CU content for PCEs with similar molecular weight. In particular, aqueous solution of PCE with a 26.0 mol % of CU showed an LCST around 36.1 °C, which was very close to the body temperature. Interestingly, it was found that the phase transition behavior changed with PCE concentration. For PCE with Mn of 2.7 kg/mol and CU content of 30.0 mol %, the LCST increased from 21.5 to 36.7 °C when the PCE concentration changed from 10 to 1 g/L. Dynamic light scattering indicated that the phase transition was possibly due to a coil‐to‐globule transition. The thermoresponsive biodegradable PCE with LCST at body temperature is promising for biomedical applications, especially for in vivo applications. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Polypyrrole stretchable actuators
Authors: Zheng Wen , Alici Gursel , Clingan Philip R. , Munro Bridget J. , Spinks Geoffrey M. , Steele Julie R. , Wallace Gordon G. 
Published: September 2012

AbstractHere, we report a simple way to prepare stretchable polypyrrole (PPy)‐based actuator materials that can be operated over a wide dynamic strain range and generate useable actuation displacements and pressures. The stretchable actuators were prepared as a laminated composite of PPy and a gold‐coated roughened rubber sheet. By manipulating the corrugated surface of the rubber substrate, the stretchability of PPy was greatly improved. Gold‐coated rubbers could be stretched to 30% without significant change in electrical resistance. The corrugated PPy/gold/rubber laminates successfully showed ∼1% of actuation strain even when prestretched to 24%. The actuation strains were smaller than for similar free‐standing PPy films and a detailed analysis of the effects of corrugation and of the rubber substrate are presented to predict actuation strain under various prestretch strains. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Plasma Etching of Poly(dimethylsiloxane): Roughness Formation, Mechanism, Control, and Application in the Fabrication of Microfluidic Structures
Authors: Vlachopoulou Maria‐Elena , Kokkoris George , Cardinaud Christophe , Gogolides Evangelos , Tserepi Angeliki 
Published: September 2012

AbstractEtching of PDMS in SF6 plasmas is investigated as planar technology for the fabrication of microfluidic devices with simultaneous control of surface topography and wettability. Plasma conditions were optimized for high etch rate, which was achieved at high plasma powers and bias voltages, where PDMS microstructures exhibited good anisotropy. Depending on the etcher wall and the mask material, topography can be controlled from very rough to almost smooth. Independent control of the topography was achieved by treating the rough surfaces with wet etchants. Open microchannels of controlled surface roughness and wettability were fabricated. Subsequently, such microchannels were irreversibly sealed with a PDMS cover plate, for fabrication of enclosed microchannels. Plasma etching of PDMS is proven to be a reliable and indispensable method for the fabrication of microfluidic devices with desired wall roughness and wettability. magnified image