bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vulcanized paper for separation of alcohol aqueous solutions by pervaporation
Authors: Trang Truong Thi Cam , Kobayashi Takaomi 
Published: February 2011

AbstractPaper membranes made from vulcanized cellulose were used for the pervaporation (PV) of aqueous solutions containing methanol, ethanol, and isopropanol. It was noted that the vulcanized cellulose paper membranes (VCPM) could effectively separate alcohol and water from the mixture solutions. To observe the effect of the separation of alcohol aqueous mixtures, the permeation behavior of water and alcohol was examined by means of the separation factor and the permeation flux. The values of the permeation flux in the ethanol/water mixtures were found to vary from 6.2 kg/m2h to 2.1 kg/m2h, as the concentration of ethanol increased from 8 to 87 wt %, and the separation factor (α) changed from α = 2.6 to 6.6, respectively. This showed that the VCPM enhanced the separation of water and alcohol. The highest value observed for the permeation flux was 11 kg/m2h at 87 wt % of methanol concentration and the separation factor at this condition was 4.1. It was shown also that an efficient separation was obtained in the isopropanol/water mixture with a separation factor of 16.6. The contact angles of alcohol/water droplets on the VCPM were measured as well as the wettability of the membrane. There was a tendency of decrease for the contact angle, as the alcohol concentration decreased. This suggested that the solvent wettability decreased in high alcohol concentrations. It was concluded that a high permeabilitty of water through the VCPM resulted in the separation of alcohols and water in the PV process. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effects of spherical silica on the properties of an epoxy resin system
Authors: Jin Hong‐Yun , Yang Yan‐Qing , Xu Liang , Hou Shu‐En 
Published: February 2011

AbstractThe spherical silica powders were prepared by using an oxygen–acetylene flame method. After spheroidization, a scanning electron microscope investigation revealed that the spheroidization efficiency of the powder was nearly 100%, XRD patterns indicated that the raw crystal silica became amorphous silica. In this study, composites of spherical silica and an epoxy resin were prepared with a homogenizer, followed by a stepwise thermal curing process. The thermal stability and thermal degradation behavior of the composites were studied by a thermogravimetric analyzer. Meanwhile, the effects of spherical silica powder on dynamic mechanical, coefficient of thermal expansion, and mechanical properties of epoxy/silica composites were also investigated. The initial decomposition temperature and mechanical properties increased significantly after adding the spherical silica into the composite. The maximum properties of thermal stability and mechanical properties were observed when spherical silica accounted for 30% of the system. The thermal expansion had been significantly reduced by the addition of silica. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis of biphenylated cyanate esters: Thermomechanical resin comparisons within two isomeric series
Authors: Reams Josiah T. , Boyles David A. 
Published: February 2011

AbstractThree isomeric tetraaryl cyanate esters containing biphenyl moieties {bis‐[4‐(4′‐cyanatophenyl)phenyl]propane, 2,2‐bis‐[4‐(3′‐cyanatophenyl)phenyl]propane, and 2,2‐bis‐[4‐(2′‐cyanatophenyl)phenyl]propane} and three isomeric triaryl cyanate esters {2‐(4′‐hydroxyphenyl)‐2‐[4′‐(4‐hydroxyphenyl)phenyl]propane, 2‐(4′‐hydroxyphenyl)‐2‐[4′‐(3‐hydroxyphenyl)phenyl]propane, and 2‐(4′‐hydroxyphenyl)‐2‐[4′‐(2‐hydroxyphenyl)phenyl]propane} were synthesized from their corresponding bisphenols. The structures of the monomers were confirmed with IR and 1H‐NMR spectroscopy. The curing behavior was investigated with differential scanning calorimetry. Cyanate esters were cured thermally in the absence of a catalyst and were characterized by dynamic mechanical analysis. The results were compared to the properties of commercial bisphenol A polycyanurate. Of the three tetraaryl isomers, 2,2‐bis‐[4‐(2′‐cyanatophenyl)phenyl]propane had the highest melting point, and its corresponding resin had the lowest glass‐transition temperature (Tg). The para isomer displayed the highest Tg value of the three novel tetraaryl resins. The triaryl dicyanate isomers were low‐melting solids, with the ortho and meta isomers existing as liquids at room temperature. The Tg value of the para‐triaryl isomer was the highest of the three triaryl isomers and was about the same as that of bisphenol A polycyanurate. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Finishing of silk by acrylic acid in the presence of sodium citrate and potassium per sulphate as catalysts under thermal treatment
Authors: Das D. , Mukherjee A. , Bhattacharya P. , Chakrabarty D. 
Published: February 2011

AbstractSilk fabric was finished using acrylic acid (AA) as the finishing agent in the presence of sodium citrate and potassium per oxodisulphate catalysts separately or in selected combinations employing a pad‐dry‐cure technique. Treatment with 6% AA at 30°C and at pH 7 produced optimum effects; a batching time of 45–60 min at 30°C, followed by drying of the batched fabric at 95°C for 5 min and curing of the dried fabric at 140°C for 5 min produced most balanced improvements in the properties such as wrinkle recovery, extensibility, and moisture regain with retention of more than 80% of original strength. Sodium citrate catalyst allowed esterification of AA with proteineous constituent of silk and potassium per sulfate catalyst allowed radical polymerization of free AA or silk bound AA moieties; the said process ultimately led to some degree of crosslinking of the chain polymers of silk. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Role of the alkyl moiety and counter ions on the thermal stability of chitosan derivatives
Authors: de Britto Douglas , Campana Filho Sergio Paulo , Assis Odilio B. G. 
Published: February 2011

AbstractThe thermal stability of alkyl chitosan derivatives (RChi) andN,N,N‐trimethyl chitosan bearing different counter ions (TMCX) was assessed by means of TG analyses. Multistep TG curves were observed for TMCX regardless of the counter ion. They exhibited lower DTG peak temperatures (TMCCl/238.2°C, TMCBr/224.5°C, TMCI/222.6°C, and TMC‐SO4/237.0°C) as compared to the parent chitosan (306.4°C) while, in contrast, the RChi showed higher DTG temperatures (ButChi/311.7°C, OctChi/327.8°C, and DodecChi/306.3°C). The apparent activation energy values determined by using the isoconversional method revealed that the RChi derivatives have low activation energy (OctChi/111.6 ± 5 kJ/mol), whereas quaternary salts have high activation energy (TMCI/155.5 ± 10 kJ/mol). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation of cationic polyurethane and its application to acrylic fabrics
Authors: El‐Sayed A. Atef , Kantouch F. A. , Kantouch A. 
Published: February 2011

AbstractThe cationic aqueous polyurethane (CAPU) coatings were prepared by reacting isophoron diisocyanate with quaternized diethanolamine (DEA) and poly(ethylene glycol) of two different molecular weights (Mn = 600 and 1000 g/mol; CAPU600 and CAPU1000). The quaternization of DEA and the formation of cationic polyurethane were investigated by Fourier transform infrared analysis. The pilling resistance and the antimicrobial property of the coated acrylic fabric were also studied. Obtained results showed that the pilling resistance of the treated fabrics increased with the increase in the concentration of the used CAPU. The acrylic fabrics treated with CAPU1000 shows higher value of pilling resistance, even at lower concentration in comparison with CAPU600. The higher the curing temperature is, the higher the pilling resistance, fabric roughness, and yellowness of the treated acrylic fabrics are. The untreated fabric showed no antimicrobial property, while the treated fabrics with CAPU showed superior antimicrobial properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Improving transfection of human pulmonary epithelial cells by doping LMW‐PEI‐g‐chitosan with β‐estradiol
Authors: Sun Peng , Zhai Xinyun , Luo Yongfeng , Ma Chaonan , Xu Jun , Liu Wenguang 
Published: February 2011

AbstractPEI‐grafted chitosan (PEI‐CMCS) copolymer was synthesized through EDC‐mediated amidation reaction between carboxymethyl chitosan and low‐molecular‐weight polyethyleneimine (LMW PEI). PEI‐CMCS and CS/DNA complexes were characterized. Compared with pristine chitosan, the PEI‐CMCS exhibited an enhanced ability to condense DNA. Incorporation of LMW PEI to chitosan was found to achieve higher transfection efficiency and much lower cytotoxicity than PEI25K at an optimum weight ratio of 15 in COS‐7 cells. However, PEI‐CMCS was incompetent to transfer refractory pulmonary epithelial cells. It was demonstrated that doping complex medium or treating cells with a steroid hormone—β‐estradiol significantly improved the transfection efficiency of 16HBE and A549 cells. This study suggests that steroid hormone may become an additive for other cationic polymers to facilitate gene transfection in pulmonary cells. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation of hydrazine‐modified polyacrylonitrile nanofibers for the extraction of metal ions from aqueous media
Authors: Saeed Khalid , Park Soo‐Young , Oh Tae‐Jin 
Published: February 2011

AbstractPolyacrylonitrile (PAN) nanofibers (prepared by an electrospinning technique) were chemically modified with hydrazine. The Fourier transform infrared spectrum of the hydrazine‐modified polyacrylonitrile (HM–PAN) showed that the intensity of the nitrile peak (2250 cm−1) of the PAN nanofibers decreased significantly after treatment with hydrazine. New peaks at about 3400–3100 cm−1 (NH stretching vibration) also appeared, which showed that the hydrazine was chemically attached to the PAN nanofibers. HM–PAN had a smooth surface (as confirmed by a scanning electron microscopy) and was a suitable material for the adsorption of metal ions from aqueous solutions. The adsorption capacity of HM–PAN increased as the adsorption time increased and became constant at 114 and 217 mg/g for Cu(II) and Pb(II) ions, respectively, after 24 h. In addition, more than 90% of the adsorbed Cu(II) and Pb(II) ions were recovered in a 1M HNO3 solution after 1 h. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
New method for estimating the extent of curing of thermosetting prepregs
Authors: Sabzevari S. M. , Alavi‐Soltani S. , Minaie B. 
Published: February 2011

AbstractHere, we propose a new method for estimating the extent of curing of thermosetting prepregs. In the proposed method, the extent of curing is estimated with the curing index (Ci), defined as the ratio of the glass‐transition temperature (Tg) to the ultimate glass‐transition temperature of the material. The advantages of this new method over the conventional degree of conversion (α) for estimating the extent of curing of thermosetting prepregs are discussed in detail. Ci and α of a toughened epoxy prepreg (977‐2 unidirectional) were obtained for a wide range of isothermal curing temperatures with a differential scanning calorimeter. The ultimate heat of reaction varied inconsistently with decreasing curing temperature; this resulted in erratic behavior of α. However, Ci provided a more consistent estimate of the extent of curing because Tg, unlike α, did not need to be modified on the basis of the curing history of the material and was measured directly with the heat‐flow data from differential scanning calorimetry. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation and properties of thermally conductive photosensitive polyimide/boron nitride nanocomposites
Authors: Li Tung‐Lin , Hsu Steve Lien‐Chung 
Published: February 2011

AbstractA new thermally conductive photoresist was developed. It was based on a dispersion of boron nitride (BN) nanoflakes in a negative‐tone photosensitive polyimide (PSPI) precursor. 3‐Mercaptopropionic acid was used as the surfactant to modify the BN nanoflake surface for the dispersion of BN nanoflakes in the polymer. The thermal conductivity of the composite films increased with increasing BN fraction. The thermal conductivity of the PSPI/BN nanocomposite was up to 0.47 W m−1 K−1 for a mixture containing 30 wt % nanosized BN filler in the polyimide matrix. Patterns with a resolution of 30 μm were obtained from the PSPI/BN nanocomposites. The PSPI/BN nanocomposites had excellent thermal properties. Their glass‐transition temperatures were above 360°C, and the thermal decomposition temperatures were over 460°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Influence of epoxy resin on the properties of maleic anhydride functionalized acrylonitrile–butadiene–styrene copolymer toughened polyamide 6 blends
Authors: Shulin Sun , Zhuo Chen , Lili Sun , Huixuan Zhang 
Published: February 2011

AbstractMaleic anhydride functionalized acrylonitrile–butadiene–styrene copolymer (ABS‐g‐MA) was used as an impact modifier of polyamide 6 (PA6). Epoxy resin was introduced into PA6/ABS‐g‐MA blends to further improve their properties. Notched Izod impact tests showed that the impact strength of PA6/ABS‐g‐MA could be improved from 253 to 800 J/m with the addition of epoxy resin when the ABS‐g‐MA content was set at 25 wt %. Differential scanning calorimetry results showed that the addition of epoxy resin made the crystallization temperature and melting temperature shift to lower temperatures; this indicated the decrease in the PA6 crystallization ability. Dynamic mechanical analysis testing showed that the addition of epoxy resin induced the glass‐transition temperature of PA6 and the styrene‐co‐acrylonitrile copolymer phase to shift to higher temperatures due to the chemical reactions between PA6, ABS‐g‐MA, and epoxy resin. The scanning electron microscopy results indicated that the ABS‐g‐MA copolymer dispersed into the PA6 matrix uniformly and that the phase morphology of the PA6/ABS‐g‐MA blends did not change with the addition of the epoxy resin. Transmission electron microscopy showed that the epoxy resin did not change the deformation mechanisms of the PA6/ABS‐g‐MA blends. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
New copolymers with heterocyclic pendant groups obtained from PVC using microwave‐assisted process
Authors: Lamanna Melisa , D'Accorso Norma 
Published: February 2011

AbstractWe report the synthesis of new copolymers from poly(vinyl chloride) (PVC) with 1,2,4‐triazol‐5‐yl‐sulfanyl pendant groups (PVCT) by nucleophilic substitution using microwave energetic sources. By comparing the synthesis of PVCT between microwave and thermal conditions, it was found that the use of microwave‐assisted process led to higher conversion levels than that of the thermal synthesis. Moreover, significant decrease in reaction times was obtained for the microwave assisted synthesis, which avoided secondary reactions. Conversion yields were calculated from elemental analysis and the molecular weighs were analyzed by means of SEC. The molecular structures of the new copolymers were confirmed by FTIR, 13C NMR and 1H NMR spectroscopies. The morphology of the new copolymers was analyzed by SEM. Thermal properties were studied by TGA and DSC techniques. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Thermal‐initiated hydroxyethyl methacrylate functionalization of multiwalled carbon nanotubes
Authors: Curtzwiler Greg , Costanzo Philip J. , Fernando Ray , Danes Jeffrey E. , Vorst Keith 
Published: February 2011

AbstractMultiwalled‐carbon nanotubes (MWCNTs) were functionalized via thermoinitiated free radical polymerization of 2‐hydroxyethyl methacrylate (HEMA) using benzoyl peroxide. Tip sonication was used during the polymerization reaction to separate agglomerated nanotubes. The functionalization was confirmed by control experiments and attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR). Differential scanning calorimetry indicated that the addition of poly(HEMA)‐MWCNTs to a two‐component polyurethane coating will have little effect on the glass transition temperature of the coating. The poly(HEMA)‐functionalized MWCNTs formed large colloidal structures of highly dispersed nanotubes in both the nonsheared and sheared coatings as determined by atomic force microscopy. This study determined a quick and easy method to functionalize MWCNTs for incorporation into a two‐component polyurethane coating. A simple method for producing ordered structures of the MWCNTs via shear observed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A novel composite coupled hardness with flexibleness—polylactic acid toughen with thermoplastic polyurethane
Authors: Hong Hua , Wei Jie , Yuan Yuan , Chen Fang‐Ping , Wang Jing , Qu Xue , Liu Chang‐Sheng 
Published: February 2011

AbstractWith the aim to modify the brittleness of polylactic acid (PLA), it was firstly melt blended with thermoplastic polyurethane (TPU) at six different PLA wt % of 100, 90, 80, 70, 60, and 50 compositions. The properties of PLA/TPU composite were characterized by means of electron microscopy, rheological, mechanical and thermal methods. The results showed that the brittle fracture of pure PLA was gradually transformed into ductile fracture with the addition of the TPU elastomer. The notched impact strength of the composite at 10 wt % TPU was over three times higher than that of pure PLA. The composite was found to be a partially miscible system with shifted glass transition temperatures. The molten blend was shear‐thinning fluid and it could be processed by conventional thermoplastic processes such as extrusion and injection molding. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis of hyperbranched polyester‐amides and their application as crosslinkers for polyurethane curing systems
Authors: Lin Dong , Liu Bing , Xu Lei , Budzinski Kristi L. , Shou Chongqi 
Published: February 2011

AbstractA series of hyperbranched polyester‐amides (S1, S2, S3) with trimethylolpropane as a core molecule were synthesized using core‐dilution/slow monomer addition strategy. The products were characterized by FTIR, 13C NMR, GPC, TGA, hydroxyl value measurement, and viscosity measurement. The result showed that the hyperbranched polyester‐amides synthesized had narrow molecular weight distribution and high degree of branching (DB). The hyperbranched polyester‐amides synthesized were used as crosslinkers for polyurethane curing systems and the mechanical properties of the polyurethane curing systems were investigated. It was found that the best tensile property and tear strength were obtained when the S2 were used as crosslinkers and the molar ratio of OH and NCO was 1 : 1. It was also found that the polyurethane curing systems had the highest hardness and Tg when the S3 were used as crosslinkers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation of nano poly(phenylsilsesquioxane) spheres(nano‐PPSQ) and study of the thermal stability and crystallization behavior of PP/nano‐PPSQ composites
Authors: Wang Xinlong , Li Jin , Wu Lianghu 
Published: February 2011

AbstractThe preparation of nano poly(phenylsilsesquioxane) particles (nano‐PPSQ) and the influence of nano‐PPSQ on the thermal stability and crystallization of polypropylene (PP) were studied. The morphology and thermal stability of PP/nano‐PPSQ composites were characterized by scanning electron microscopy (SEM) and the thermogravimetric analysis (TGA). The SEM result showed that the particles were well dispersed in the PP matrix. The TGA results of the PP/nano‐PPSQ composites indicated that the incorporation of nano‐PPSQ can improve the thermal stability of PP. The crystallization behavior and kinetics of PP/nano‐PPSQ composite were studied by X‐ray diffraction (XRD) and differential scanning calorimetry (DSC). The XRD revealed that the addition of nano‐PPSQ influences the crystallinity and crystal size of PP. The Avrami, Ozawa, and combined Avrami/Ozawa (Mo method) equations were applied to describe the crystallization kinetics and estimate the kinetic parameters of mathematical models under the nonisothermal crystallization of PP and PP/nano‐PPSQ composites. The results show that nano‐PPSQ influences the crystallization temperature and rate. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Recycling of chrome‐tanned leather waste in acrylonitrile butadiene rubber
Authors: El‐Sabbagh Salwa H. , Mohamed Ola A. 
Published: February 2011

AbstractChrome‐tanned leather waste generated in huge amount from leather industry causing environmental problem; this leather waste was used as filler in acrylonitrile butadiene rubber before treatment and after treatment with ammonia solution and sodium formate. Different formulations of acrylonitrile butadiene rubber/leather waste (untreated–treated with ammonia solution—treated with sodium formate) composites are prepared. The formed composites exhibit a considerable improvement in some of their properties such as rheometric characteristics especially with composites loaded with treated leather waste. Tensile strength, modulus at 100% elongation, hardness, and Young's modulus were improved for composite loaded with treated leather. Crosslinking density in toluene was increased by the incorporation of leather wastes treated or untreated resulting in decreases in swelling equilibrium. Distinct increase in the ageing coefficient and the thermal stability for composites loaded with both treated and untreated leather. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Lignin‐based activated carbon fibers and controllable pore size and properties
Authors: Shen Qing , Zhang Tao , Zhang Wen‐Xin , Chen Shuai , Mezgebe Mebrahtu 
Published: February 2011

AbstractSeveral lignin‐based activated carbon fibers (ACFs) were prepared by initial synthesis of lignin–phenol–formaldehyde (LPF) resins with varied lignin contents, 8–20%, respectively, and then the melt spinning and thermal treatments. Because the guaiacyl groups of lignin reacted with the formaldehyde, the role of lignin played becomes a dominator for controlling the thermal properties of LPF resin and the pore size and related properties of ACFs. This was proven by the comparison of the scanning electron microscope photographs of all prepared ACFs. FTIR spectra showed that the ACFs were structured by lignin‐contributed carbons. The porosity and adsorption behavior of these ACFs were also studied and compared. Results showed that the ACFs with 14% lignin content have better pore structure and adsorption properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Dynamic rheology and morphology of polylactide/organic montmorillonite nanocomposites
Authors: Wang Biao , Wan Tong , Zeng Wei 
Published: February 2011

AbstractThe effects of organic montmorillonite (OMMT) on the rheological behaviors and phase morphology of polylactide (PLA) were investigated. The rheological behaviors of nanocomposites showed mainly dependence on both temperature and OMMT content. At low OMMT loading (1 wt %), the complex viscosities showed a Newtonian plateau in low frequency region at low temperatures and converted to a shear‐thinning behaviors with increasing temperature. In comparison, at high OMMT loadings (above 5 wt %), strong shear‐thinning behaviors were observed in the full range of frequencies and temperatures. The results demonstrated rheology of PLA/OMMT is highly sensitive to the nanofillers filled materials. A pseudo‐solid‐like behavior at long scale time in the hybrids with OMMT loading was higher than 5 wt %, this response was related to the formation of a network structure across the polymer matrix due to strong interactions of PLA and OMMT that confined the relaxation process of the macromolecules. X‐ray diffraction and transmission electron microscopy indicated the nanocomposites at low OMMT loading were mainly exfoliated and intercalated nanocomposites were gradually formed with increasing OMMT loading. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011