bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of a macromolecular coupling agent on the properties of aluminum hydroxide/PP composites
Authors: Plentz Rafael S. , Miotto Maximiliano , Schneider Elisangela E. , Forte Mş Madalena C. , Mauler Raquel S. , Nachtigall Sonia M. B. 
Published: May 2006

AbstractPolypropylene (PP)/aluminum hydroxide (ATH) composites were prepared in a melt mixer with addition of polypropylene functionalized with vinyltriethoxysilane (VTES) as a coupling agent. The effects of ATH and PP‐VTES on the melt flow indices (MFI), tensile properties, decomposition temperatures, and flame retardancy of composites were analyzed. It was verified that increased ATH concentration reduced MFI and tensile properties, but increased the decomposition temperature under oxidative atmosphere and improved the flammability properties. Addition of PP modified with VTES slightly improved tensile strength and maximum elongation and granted the best results for the flammability tests of the materials showing that it can be an effective coupling agent for PP/ATH composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1799–1805, 2006
Preparation and characterization of ciprofloxacin‐loaded alginate/chitosan sponge as a wound dressing material
Authors: Öztürk Eylem , Ağalar Canan , Keçeci Kaan , Denkbas̨ Emir B. 
Published: May 2006

AbstractThe aim of this study is preparation and characterization of alginate/chitosan sponges including a model antibiotic (i.e., ciprofloxacin) to use in wound and/or burn treatment. Sponges were prepared firstly by the gelation of sodium alginate followed by lyophilization, crosslinking with calcium chloride, and finally coating with chitosan. Sponges were characterized with respect to morphology, water uptake, in vitro drug release behavior, and antimicrobial activity. Investigated and evaluated parameters in all of these studies were selected as the concentration of calcium chloride, alginate viscosity, drug content, and molecular weight of chitosan. Drug release and water uptake were found to be greatly influenced by these parameters. Water uptake and drug release rate were decreased by increasing the crosslinking density, chitosan molecular weight, and alginate viscosity. In the antimicrobial tests, it was obtained that the antimicrobial activity is directly proportional with the release rates and water uptake. Morphological studies showed a highly porous structure with interconnected pores. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1602–1609, 2006
Phase behavior and properties of in situ‐reinforcing elastomer composites based on thermoplastic elastomers and thermotropic liquid crystalline copolyester
Authors: Saikrasun Sunan , Amornsakchai Taweechai 
Published: May 2006

AbstractIn situ reinforcing composites based on two elastomer matrices very different in melt viscosity, styrene–(ethylene butylene)–styrene triblock copolymer (Kraton G1650) and styrene–(ethylene propylene) diblock copolymer (Kraton G1701), and a thermotropic liquid crystalline polymer (TLCP), Rodrun LC3000, were prepared using a twin‐screw extruder. The rheological behavior, morphology, mechanical and thermal properties of the blends containing various LC3000 contents were investigated. G1650 was found to have much higher shear viscosity than G1701. All neat components and their blends exhibited shear thinning behavior. Melt viscosity of the blends gradually decreased with increasing LC3000 contents. Despite a large difference in melt viscosity of the two matrices, the results showed that the fibrillar morphology was obtained for both as‐extruded strands of LC3000/G1650 and LC3000/G1701 with up to 30 wt % LC3000. At 40 wt % LC3000 or more, the lamellar structure was observed for both types of blends because of the coalescence of liquid TLCP threads that occurred during extrusion. The addition of LC3000 into both elastomer matrices enhanced the tensile modulus considerably whereas the extensibility remarkably decreased. The results obtained from thermogravimetric analysis suggested that an addition of LC3000 into both elastomer matrices improved the thermal resistance significantly in air, but not in nitrogen. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1610–1619, 2006
Separation of phenol from aqueous solution by membrane pervaporation using modified polyurethaneurea membranes
Authors: Sinha Barun , Ghosh Ujjal K. , Pradhan Narayan C. , Adhikari Basudam 
Published: May 2006

AbstractHydroxy‐terminated polybutadiene‐based porous and nonporous polyurethaneurea membranes were prepared and used to study the phenol separation efficiency from dilute aqueous solution. The porosity was developed by incorporation of lithium chloride in polymer matrix with subsequent leaching of the same in hot water. The porous membrane showed higher phenol flux over that of nonporous membrane. Permeate containing about 97 wt % phenol was obtained from feed containing 7 wt % phenol, when pervaporation was carried out with porous polyurethaneurea membrane at 75°C. The activation energies for diffusion, permeation, and pervaporation were calculated from Arrhenius plots. From the activation energy values, it was observed that the pervaporation process became easier with increased phenol concentration in the feed and porosity of the membrane used. The membrane boundary resistance was observed to decrease with increase in temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1857–1865, 2006
The effect of crosslinking on the mechanical properties of polylactic acid/polycaprolactone blends
Authors: Semba Takeshi , Kitagawa Kazuo , Ishiaku Umaru Semo , Hamada Hiroyuki 
Published: May 2006

AbstractThe improvement of the brittle behavior of Polylactic acid (PLA) resin was studied by blending it with Polycaprolactone (PCL) resin. These materials were fabricated into the compressed films and injection moldings. The values of tensile modulus and strength were appropriate, judging from the rule of mixtures. However, the ultimate tensile strain was very small. Dicumyl peroxide (DCP) was added to this blend system to improve its ultimate tensile strain. It was found that the value of ultimate tensile strain peaked at low DCP concentration. The samples at low DCP contents show yield point and ductile behavior under tensile test. The impact strength of the optimum composition was 2.5 times superior to neat PLA, and ductile behavior such as plastic deformation was observed at its fracture surface. It was found that the carbonyl groups of the blend material with DCP were altered by using FTIR spectroscopy. Dynamic mechanical analysis data revealed the dual phase nature of PLA/PCL blend albeit with good interfacial adhesion, and the DCP enhanced the viscous property in PCL phase, which agreed with tensile ductility and impact strength. The mechanical properties of this blend are comparable to those of general purpose HIPS and ABS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1816–1825, 2006
pH electrodes constructed from polyaniline/zeolite and polypyrrole/zeolite conductive blends
Authors: Malkaj P. , Dalas E. , Vitoratos E. , Sakkopoulos S. 
Published: May 2006

AbstractA new type of solid state electrodes sensitive to pH changes is described, in which the chemical‐sensitive layer consists of Pt microparticles deposited on a conducting polymer (polyaniline, polypyrrole) blend containing 22.7% w/w zeolite. These sensors are stable in aqueous electrolyte solutions of low pH value at temperatures up to 45°C with response time in seconds. At 25°C, sensor sensitivity was −310 ± 40 mV/pH and −1300 ± 100 mV/pH for polyaniline and polypyrrole blends, respectively. Interferences appear to be acceptably small. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1853–1856, 2006
A novel alkoxysilane‐modified high solids hydroxyl acrylic polyurethane: Preparation and surface properties
Authors: Zhu Fang , Zhang Gaoyong , Xu Shuyi , Hong Xinlin , Dong Jinfeng 
Published: May 2006

AbstractAlkoxysilane‐modified high solids hydroxyl acrylic polyurethane was prepared by solution polymerization. Its structure, surface, and thermal properties were investigated by 1H NMR, device of contact angle, thermo gravimetric analysis (TGA), atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy (XPS). Research showed that alkoxysilane modified high solids hydroxyl acrylic polyurethane has superior properties that can be used for automotive paints. The contents of silicone in the alkoxysilane‐modified high solids hydroxyl acrylic polyurethane were 1.25, 1.5, 2, and 2.5 wt %. In this study, γ‐methacryloxypropyltrimethoxysilane (MPTS) was chosen as the modifier. Results showed that the contact angles of water and surface roughness on the film of MPTS modified high solids hydroxyl acrylic polyurethane increased, and thermal stability of the film at high temperatures improved with the increasing of the silicone content in the resins. MPTS modified high solids hydroxyl acrylic polyurethane with 2.5 wt % silicone content had better water resistance, better acid resistance, higher hardness, and excellent weatherability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1866–1871, 2006
Preparation and properties of crosslinked chitosan thermosensitive hydrogel for injectable drug delivery systems
Authors: Zan Jia , Chen Huanhuan , Jiang Guoqiang , Lin Ying , Ding Fuxin 
Published: May 2006

AbstractThe aim of this study was to prepare and investigate the physical properties of a thermosensitive crosslinked chitosan pregel solution, and evaluate the in vitro release profiles of macromolecules from this sol–gel transition system. Chitosan and poly (vinyl alcohol) were used to form an interpenetrating polymeric network with glutaraldehyde as the crosslinker, and glycerophosphate (GP) was added to transform the pH‐dependent solutions into thermosensitive pH‐dependent solutions. Rheological study showed that the gelation was dependent on the crosslink degree and GP concentration of the solution. The crosslinked gel had excellent mechanic properties and no apparent “pores” and formed an integrated hydrogel texture according to scanning electronic micrograph. Gas chromatography test guaranteed the medication safety with no detection of glutaraldehyde remnants in the hydrogels. In vitro release study showed that the gelation does not significantly affect the macromolecules diffusion but the crosslinking degree does. These results indicated that the hydrogel formed an intensified three‐dimensional hybrid network with interpenetrating molecules, which effectively buffered or delayed the macromolecules diffusion. The hydrogels sustained the drug release over 30 days and could be potentially used as in situ gelling implants. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1892–1898, 2006
Miscibility and hydrolytic degradation of bioreabsorbable blends of poly(p‐dioxanone) and poly(L‐lactic acid) prepared by fusion
Authors: Pezzin A. P. T. , Duek E. A. R. 
Published: May 2006

AbstractBlends of two semicrystalline polymers, poly(L‐lactic acid) (PLLA) and poly(p‐dioxanone) (PPD), were prepared by melting the polymers in different proportions. The miscibility, thermal behavior, dynamic‐mechanical properties, and morphology of these blends were studied using differential scanning calorimetry (DSC), dynamic‐mechanical analysis (DMA), and scanning electron microscopy (SEM). The melting temperature of PPD, determined by DSC, did not change with increasing PLLA content, suggesting that this system was immiscible. The presence of two glass transition temperatures detected by DMA also indicated the total immiscibility of the two polymers and this phase separation was confirmed by SEM. The stability of blends immersed in tubes containing phosphate buffer (pH = 7.4) in a thermally controlled bath at (37 ± 1)°C was assessed using DSC, thermogravimetric analysis (TGA), and SEM. PLLA degraded more slowly than PPD, whereas the blends had a degradation rate that was intermediate to these two polymers. This finding indicated that it was possible to control the degradation rate of the blend by changing its composition. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1899–1912, 2006
ZnS deposition on oxadiazole–terpyridine copolymer
Authors: Chrissanthopoulos A. , Tzanetos N. P. , Andreopoulou A. K. , Kallitsis J. , Dalas E. 
Published: May 2006

AbstractThe combination of inorganic salts and macromolecules leads to supramolecular structures with new interesting physical and chemical properties. The deposition of ZnS (Wurtzite) on oxadiazole–terpyridine copolymer P‐90/10 synthesized by free radical copolymerization were investigated. The apparent order of the crystallization process was found to be 2 that indicated a surface diffusion‐controlled mechanism. Critical nucleus formation proceeds via complexation of the ZnS molecules to the N atoms as concluded from computational chemistry calculations. The number of ions forming the critical nucleus was found experimentally to be (n*exp = 1.71 ± 0.24) in accordance with the computational chemistry calculations by the PM3 method of the MOPAC program package. The surface energy of the growing ZnS phase was found to be 121 mJ/m2 typical for sparingly soluble salts. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1913–1918, 2006
Enhancing the efficiency of MEH‐PPV and PCBM based polymer solar cells via optimization of device configuration and processing conditions
Authors: Chang En Chung , Chao Ching‐Ian , Lee Rong‐Ho 
Published: May 2006

AbstractPolymer solar cells were fabricated based on an interpenetrated network of conjugated polymer poly(2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐1,4‐phenylenevinylene) (MEH‐PPV) as electron donor and fullerene derivative (6,6)‐phenyl‐C61‐butyric acid methyl ester (PCBM) as electron acceptor. The photovoltaic performances were strongly dependent on the surface treatment of anode, conductivity of hole‐transporting material, the thickness of MEH‐PPV:PCBM composite film, and the cathode configuration. Best photovoltaic performances were obtained for the solar cell constructed with O2 plasma‐treated anode glass, high conductivity hole‐transporting material PEDOT, photoactive film thickness of 180 nm, and calcium/silver cathode. Open circuit voltage of 0.79 V, short circuit current density of 4.79 mA/cm2, fill factor of 44.4%, and 2.07% power conversion efficiency were obtained for the solar cell under 80 mW/cm2 white light from a halogen lamp. The influences of device fabrication conditions and configuration on the photovoltaic performance of MEH‐PPV:PCBM composite film‐based polymer solar cells were discussed in detail. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1919–1924, 2006
Determination of the infinite dilution diffusion and activity coefficients of alkanes in polypropylene by inverse gas chromatography
Authors: Zhao Changwei , Li Jiding , Zeng Chuyi 
Published: May 2006

AbstractInfinite dilution diffusion and activity coefficients of n‐hexane, n‐heptane, and n‐decane in polypropylene were measured from 373.15 to 393.15 K by inverse gas chromatography. The influences of small molecule solvent and temperature on the infinite dilution diffusion and activity coefficients were investigated. The results showed that the infinite dilution diffusion coefficient decreased but the infinite dilution activity coefficient increased with an increasing number of CH2 group in the aliphatic solvents. The temperature increase resulted in the increase in the infinite dilution diffusion coefficient and the decrease in the infinite dilution activity coefficient. The graphs plotted according to the results of the infinite dilution diffusion coefficient versus temperature were in agreement with the Arrhenius equation. Diffusion constant and activation energy were obtained from the Arrhenius equation. Also, the interdependence on the infinite dilute activity coefficient and temperature accorded with Gibbs‐Helmholtz equation. From the temperature dependence of the limiting activity coefficients partial molar excess enthalpy at infinite dilution HE,∞ was obtained. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1925–1930, 2006
Anionic polymerization of lactams: A comparative study on various methods of measuring the conversion of ε‐caprolactam to polyamide 6
Authors: Zhang Cai‐Liang , Feng Lian‐Fang , Hu Guo‐Hua 
Published: May 2006

AbstractAnionic ring‐opening polymerization of lactams leads to the formation of poly(lactams) or polyamides. This work aimed at comparing the performance of four methods for measuring the conversion of ε‐caprolactam (CL) to polyamide 6. The latter was either a homopolymer (PA6) or grafts onto polystyrene (PS‐g‐PA6 graft copolymer). Those four methods were mass balance based on solvent extraction (methanol, water, THF, or acetone), mass balance based on vacuum drying at 140°C, thermogravimetric analysis (TGA), and elemental analysis based on nitrogen. The mass balances based on methanol extraction and vacuum drying at 140°C and TGA were all suitable for measuring the conversion of CL, whether the resulting polymer was the PA6 or PS‐g‐PA6. The mass balance based on water extraction was good for the PA6 and not good for the PS‐g‐PA6. The elemental analysis based on nitrogen was not suitable for the PA6 nor for the PS‐g‐PA6. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1972–1981, 2006
Effects of crosslinking time and amount of sulfophthalic acid on properties of the sulfonated poly(vinyl alcohol) membrane
Authors: Chanthad C. , Wootthikanokkhan J. 
Published: May 2006

AbstractA proton‐exchange membrane for a direct methanol fuel cell was prepared by modifying the chemical structure of poly(vinyl alcohol) (PVA) via a sulfonation. The sulfonation was carried out by using sulfophthalic acid (sPTA) as a sulfonating agent. The sulfonated PVA membranes, with a variety of degrees of substitutions, were obtained by varying the crosslinking time and the amount of sulfonating agents. The chemical structure and thermal stability of the sulfonated PVA were characterized by using FTIR and thermogravimetric analysis techniques, respectively. The ion‐exchange capacity (IEC) and water uptake of the sulfonated membranes was evaluated by titration and gravimetry techniques, respectively. It was found that the IEC of the membrane increased with the amount of sPTA. Water uptakes of the membranes could either decrease or remain unchanged with the crosslinking time, depending on the amount of the sulfonating agent used. Methanol permeability values of the membranes treated with 10% sPTA were relatively low, comparing with that of the Nafion 115 membrane. Proton conductivity values of the sulfonated PVA membranes ranged between 0.024 and 0.035 S/cm and they did not remarkably change with the crosslinking time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1931–1936, 2006
Preparation and characterization of poly(silyl ester)s containing 2,2‐bis(p‐dimethylsiloxy‐phenyl)propane units in the polymer backbones
Authors: Han Nianfeng , Liu Zonglin , Jin Liqiang , Yue Yun 
Published: May 2006

AbstractThe two poly(silyl ester)s containing 2,2‐bis(p‐dimethylsiloxy‐phenyl)propane units in the polymer backbones have been prepared via polycondensation reaction of di‐tert‐butyl adipate and di‐tert‐butyl fumarate with 2,2‐bis(p‐chloro dimethylsiloxy‐phenyl)propane to give tert‐butyl chloride as the condensate. The polymerizations were performed under nitrogen at 110°C for 24 h without addition of solvents and catalysts to obtain the poly(silyl ester)s with weight average molecular weights typically ranging from 5000 to 10,000 g/mol. Characterization of the poly(silyl ester)s included 1H NMR and 13C NMR spectroscopies, infrared spectroscopy, ultraviolet spectroscopy, differential scanning calorimetry, thermogravimetric analysis (TGA), gel permeation chromatography, and Ubbelohde viscometer. The glass transition temperatures (Tg) of the obtained polymers were above zero because of the introducing 2,2‐bis(p‐dimethylsiloxy‐phenyl)propane units in the polymer backbones. The TGA/DTG results showed that the obtained poly(silyl ester)s were stable up to 180°C and the residual weight percent at 800°C were 18 and 9%, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1937–1942, 2006
Synthesis and properties for interpenetrating polymer network of modified epoxy resins
Authors: Ho T. H. , Leu T. S. , Cheng S. S. 
Published: May 2006

AbstractThe control epoxy resin, CE (i.e., without modified), containing naphthalene group was synthesized directly from 1,6‐dihydroxynaphthalene with epichlorohydrin and a stoichiometric of NaOH. The MDI (4,4′‐diphenylmethane diisocyanate)‐modified epoxy resins, ME, were prepared from the direct process, MDI with CE. Subsequently, they were cured from various composition of ME/CE with 4,4′‐diaminodiphenylsulfone (DDS) and tetramethyl bisphenol F dicyanate (TBFD) in equal equivalent, respectively. In addition, the cure reaction was studied through a cross‐reference between in situ Fourier transform infrared and DSC (differential scanning calorimeter) dynamic scanning. The kinetic model gives a good description of curing paths. The modified epoxy systems had higher activation energy than that of control epoxy resin. The epoxy resins with 10 wt % ME‐modified was found to obtain appropriate result in combination with optimum properties and content (e.g., thermal stability, glass‐transition temperature, coefficient of thermal expansion, moisture absorption, dielectric constant, and modulus etc.), which may be attributed to the naphthalene, oxazolidinone structure, and crosslink density contributed to optimal state in polymer matrices. Furthermore, the intermolecular interaction hydrogen bonding of interpenetrating polymer networks. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1872–1879, 2006
Polybenzyl methacrylate brush used in the top‐down/bottom‐up approach for nanopatterning technology
Authors: Tsai Yuhsin , Wang Wei‐Ching 
Published: May 2006

AbstractAtom‐transfer radical polymerization (ATRP) of benzyl methacrylate (BzMA) at ambient temperature was applied to step and flash imprint lithography. This process involved the formation of patterned polymeric networks (top‐down) and the grafting polymerization of BzMA from these networks (bottom‐up) via ATRP. Confocal laser scanning microscope and scanning electron microscope were used to determine the change in line‐to‐line separation (width) resulting from poly BzMA brush. The increase in line width at 400 nm could be maximized given a reaction time of 2 h. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1953–1957, 2006
Hydrophobic polymers as barrier dispersion coatings
Authors: Vähä‐Nissi Mika , Kervinen Kirsi , Savolainen Antti , Egolf Scott , Lau Willie 
Published: May 2006

AbstractThe aim of this study was to evaluate the properties of polymer dispersions prepared from hydrophobic monomers as barrier coatings. These dispersions were produced using a new emulsion polymerization process involving cyclodextrin as a phase‐transport catalyst. Conventional emulsion polymerization techniques are not applicable due to the low water solubility of the monomers, such as lauryl and stearyl (meth)‐acrylates. The experimental polymers showed improvements in water and water vapor barriers, as a result of the incorporation of hydrophobic monomers. The barrier properties could be further improved with functional groups, crosslinking, and chain‐regulating agents, as well as fillers. Grease and water barriers were strongly affected by pinholes, and functional monomers appeared to be effective in enhancing the grease barrier property. Particle morphology, glass transition temperature, and drying affected the performance of these dispersions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1958–1962, 2006