bluuebunny/crossref_metadata_2025_split huggingface dataset:
The degradation and prestabilization of acrylonitrile copolymers
Authors: Cui Chuansheng , Yu Lina , Wang Chengguo 
Published: March 2010

AbstractThe degradation and prestabilization of polyacrylonitrile (PAN) were investigated with differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The initial temperature, initial loss‐weight temperatures, and loss‐weight were significantly lowered when ammonium itaconate (AIA) was used as comonomer. One exothermal peak of PAN (homopolymer) was shown in the DSC curves, while there were four exothermal peaks of poly(AN‐AIA). FTIR spectra results confirm the degradation process of NH groups. During the heating process, NH groups (3030 cm−1) were changed into NH (2955 cm−1) and then NH groups (2920 cm−1). The dissociated H+ could initiate the cyclization reactions of CN companied with heat released. The effect of ammonia on degradation and prestabilization of PAN was also studied. It was found that ammonia could accelerate prestabilization of acrylic precursors. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of nano‐sized ZnO and polyaniline‐zinc oxide composite: Characterization, stability in terms of DC electrical conductivity retention and application in ammonia vapor detection
Authors: Khan Asif Ali , Khalid Mohd. 
Published: March 2010

AbstractNano‐sized particles of Zinc oxide (ZnO) were synthesized using a new chemical rout. The chemical oxidative polymerization of aniline in the presence of nano ZnO was employed to synthesize a polyaniline‐zinc oxide (PANI‐ZnO) nanocomposite. The material was characterized by using transmission electron microscopy, XRD, scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and Thermogravimetric analysis (TGA). The conductivity measurements showed the resulting composites possessed higher conductivity as compared to pure polyaniline (PANI). The nanocomposite exhibited fairly sensitive towards solution of aqueous ammonia (NH3), when it was exposed to various concentrations of NH3 in an ambient room temperature. The results show that the sensor has good sensitivity and good repeatability upon repeated exposure to NH3. PANI‐ZnO nanocomposite was also used to study electrical conductivity under isothermal conditions in the temperature range 50–130°C. The composite was found stable under ambient conditions below 90°C in terms of DC electrical conductivity retention. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Properties of epoxy novolak resin layers doped with bismuth for photoluminescence near 1300 nm
Authors: Prajzler Václav , Lyutakov Oleksiy , Hüttel Ivan , Špirková Jarmila , Oswald Jiří , Machovič Vladimír , Jeřábek Vítězslav 
Published: March 2010

AbstractIn this article, we report on the optical properties of bismuth ions doped epoxy novolak resin (ENR). The polymer layers containing 1–20 at. % of bismuth were fabricated by spin coating onto silicon or quartz substrates. The properties of the material were studied using several methods with special regards to its potential utilization in photonics devices. Absorption spectra were taken in the range from 350 to 800 nm. Optical band gap Eg was determined from the absorption coefficient values using Tauc's procedure, i.e., from the relationship αhv = A(hv − Eg)2 and the obtained values varied from 2.94 to 3.23 eV depending on the amount of bismuth ions involved in the samples. Photoluminescence spectra around 1300 nm were recorded by using excitation of semiconductor lasers operating at 808 nm (Ex = 500 mW). Optical properties of bismuth‐doped ENR were evaluated on the bases of the concentration of the bismuth ions involved in the samples and showed, e.g., close relations between concentration of the dopants and intensity of the luminescence band at 1300 nm. IR spectra showed only negligible changes in the original substrate resin. Our results proved that the bismuth‐doped ENR have a potential for utilization in photonic devices. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of nanocomposites based on a furan resin
Authors: Rivero Guadalupe , Vázquez Analía , Manfredi Liliana B. 
Published: March 2010

AbstractFormaldehyde emissions are nowadays trying to be reduced because of its atmospheric pollutant character. Besides, it is encouraged the use of polymeric materials synthesized from biomass wastes as row materials. For this reason, furan resins would be an alternative to phenolic resins, where formaldehyde is replaced by furfural as a reactant. Regarding, the addition of nanoparticles to the furan resin should enhance their performance as metal coatings with good thermal and oxidative resistance. The aim of this article is to study the influence of the in situ addition of different type of nanoparticles on the chemical reactions involved in the synthesis of a furan resin. From the viscosity measurements it was observed that the addition of the nanoreinforcements led to a higher resin reaction rate. Differences in the final chemical structure among the materials were also observed by infrared spectroscopy analyses. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Characterization of poly(lactic acid) multifilament yarns. I. The structure and thermal behavior
Authors: Radjabian M. , Kish M. H. , Mohammadi N. 
Published: March 2010

AbstractThe structure and thermal behavior of poly(lactic acid) (PLA) multifilament yarns were studied by complementary techniques of differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, and wide angle X‐ray diffraction (WAXD). As for PLA filaments, notable differences in the WAXD patterns, DSC curves, and FTIR spectra were observed. The combination of the WAXD and FTIR results showed that PLA samples with different crystallinity contain α‐form crystal structure. The FTIR spectra of the filaments were analyzed to study their crystallinity and crystal structure. The total crystallinity of the PLA filaments was obtained from the percent area loss of the skeletal amorphous band at 955 cm−1. Crystalline fraction from FTIR and DSC were comparable with each other. The CO stretching region, which is sensitive to crystallization and dipole–dipole interactions, was evaluated to provide information about chain conformers and crystallinity of the samples. Depending on the processing conditions, double melting peaks were observed in the DSC curves of the samples. This exhibited the structural reorganization of the crystal phase during heating affected by heating and cooling rate. In the DSC curves of the nearly amorphous multifilament yarn, the exothermic peak observed right above the glass transition temperature (Tg) indicated two relaxed and deformed amorphous regions. However, the multifilament yarn with higher crystallinity showed just endothermic melting peak after its glass transition. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Oxazoline functionalized polystyrene as a compatibilizer for dispersion of organoclay in polyphenylene ether blends
Authors: Sangaj Nivedita , Mohite Amol , Sadasivam G. , Franklin Sushmita , Guo Hua 
Published: March 2010

AbstractAddition of external additives as compatibilizers is known to improve exfoliation of nanoclay in various polymeric matrices. This study found that oxazoline functionalized polystyrene (OPS) is an effective compatibilizer to improve the dispersion of organoclay (Cloisite 20A) in polyphenylene ether (PPE)‐based blends. The main objective of this study was to understand the mechanism of OPS as a compatibilizer for dispersion of nanoclay in PPE‐based blends and evaluate whether the master‐batch of organoclay in OPS can be used to disperse nanoclay in various PPE‐based blends irrespective of the type of the other polymer component in the blend. Although the addition of OPS to polystyrene (PS) alone resulted in mere intercalation of organoclay, its addition to PPE‐based blends was found to result in mixed clay dispersion of intercalated, exfoliated, and to some extent collapsed phases. Addition of OPS‐organoclay combination in master‐batch mode showed similar results as direct mode addition. At least 15% of OPS was required for effective dispersion of Cloisite 20A in PPE‐high impact polystyrene blend. The possible role of solubility of OPS in the matrix and high melt shear of PPE‐based matrix was investigated to understand the exclusive action of OPS in PPE‐based blends. X‐ray diffraction and transmission electron microscopy techniques were used to study the organoclay dispersion. Further master batches of organoclay in neat OPS and OPS containing PPE‐based blends were evaluated in other PPE‐based commercial blends. Of the various blends studied, blend containing phosphite additive showed better dispersion of organoclay. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of the viscosity ratio on the morphology and properties of PET/HDPE blends with and without compatibilization
Authors: Mbarek Souad , Jaziri Mohamed , Chalamet Yvan , Carrot Christian 
Published: March 2010

AbstractThe influence of the molecular weight of polyethylene on the morphology and mechanical properties of blends of high‐density polyethylene (HDPE) dispersed as droplets in a poly(ethylene terephthalate) (PET) matrix at various compositions was investigated. The difference of morphologies can be easily explained by the influence of the molecular weight on the viscosity ratio and therefore, on the critical capillary number. The compatibilizing efficiency of copolymers containing glycidyl methacrylate groups was also addressed in relation to their nature, the protocol for their drying and the molecular weight of the HDPE phase. The increase of adhesion between PET and HDPE was found to have a larger influence on tensile properties than the reduction of interfacial tension. The amount of compatibilizer needed for adhesion improvement depends on the interfacial area that is defined by both the interfacial tension and viscosity ratio of the components. A qualitative relation between the optimum amount of compatibilizer and the critical capillary number can be written. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Water vapor sorption kinetics of wood modified with glutaraldehyde
Authors: Xie Yanjun , Hill Callum A. S. , Xiao Zefang , Jalaludin Zaihan , Militz Holger , Mai Carsten 
Published: March 2010

AbstractThe modifying effects of Scots pine (Pinus sylvestris L.) wood with the crosslinking agent glutaraldehyde (GA) on the water vapor sorption kinetics were studied by curve fitting the experimental isotherm sorption data obtained using a Dynamic Vapor Sorption apparatus using the parallel exponential kinetics model (PEK model) and the Hailwood–Horrobin model (H–H model) for the isotherm. Both the H–H model and the PEK model provided good fits to the experimental data. Modification of wood with GA reduced both the time to equilibrium and the equilibrium moisture content (EMC). According to the PEK and H–H models, the reduction in EMC was mainly due to the decrease of moisture content (MC) associated with the slow sorption processes and polylayer water. The fast sorption processes and monolayer water were little affected by GA modification. Compared to the untreated control, the estimated total water absorbed by wood treated to a WPG of 20.9% at 100% RH decreased by 52.2%, by extrapolating the fitted curves derived from the H–H model. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Reinforcement of polyurethane‐based shape memory polymer by hindered phenol compounds and silica particles
Authors: Kuriyagawa Mizue , Kawamura Takanobu , Hayashi Shunichi , Nitta Koh‐Hei 
Published: March 2010

AbstractReinforcement of polyurethane‐based shape memory polymer materials was investigated by adding hindered phenol compounds and silica particles. According to dynamic mechanical analysis, these fillers had no effect on the glass transition temperature and the activation energy of soft segments, indicating that the fillers have no ability to influence the molecular mobility of soft segments. It was found from the tensile tests that the yield stress was increased primarily by addition of the hindered phenols rather than the silica particles, whereas Young's modulus was enhanced by the silica particles rather than the hindered phenols. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Mechanical, thermal, and morphological properties of maleic anhydride‐g‐polypropylene compatibilized and chemically modified banana‐fiber‐reinforced polypropylene composites
Authors: Chattopadhyay Sanjay K. , Khandal R. K. , Uppaluri Ramagopal , Ghoshal Aloke K. 
Published: March 2010

AbstractComposites were prepared with chemically modified banana fibers in polypropylene (PP). The effects of 40‐mm fiber loading and resin modification on the physical, mechanical, thermal, and morphological properties of the composites were evaluated with scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Infrared (IR) spectroscopy, and so on. Maleic anhydride grafted polypropylene (MA‐g‐PP) compatibilizer was used to improve the fiber‐matrix adhesion. SEM studies carried out on fractured specimens indicated poor dispersion in the unmodified fiber composites and improved adhesion and uniform dispersion in the treated composites. A fiber loading of 15 vol % in the treated composites was optimum, with maximum mechanical properties and thermal stability evident. The composite with 5% MA‐g‐PP concentration at a 15% fiber volume showed an 80% increase in impact strength, a 48% increase in flexural strength, a 125% increase in flexural modulus, a 33% increase in tensile strength, and an 82% increase in tensile modulus, whereas the heat deflection temperature increased by 18°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Water in dextran hydrogels
Authors: Chen Jun , Yi Ju‐Zhen , Zhang Li‐Ming 
Published: March 2010

AbstractA series of dextran hydrogels were synthesized with potassium chloride as a crosslinker. 13C‐NMR and 17O‐NMR were used to study the crosslinking role of potassium chloride. Differential scanning calorimetry and thermogravimetric analysis were used to study the state and properties of water in the dextran hydrogels. We found there were three kinds of water in the physically crosslinked dextran hydrogels: free water, freezing bound water, and nonfreezing water. The maximum amount of nonfreezing water in the 50% dextran hydrogel was about 8%. Both 13C‐NMR and 17O‐NMR spectra proved that KCl played the crosslinking role and it interacted with dextran via the oxygen atoms linked to C4 and C6 and, also, the oxygen atom linked to C1 on the dextran ring. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
An investigation on the progressive change in filament characteristics from outer to inner layers of mulberry and tasar cocoons
Authors: Das Subrata , Ghosh Anindya 
Published: March 2010

AbstractThe physical properties and residual sericin content of the silk filament were evaluated in relation to its position in different layers of the cocoons corresponding to Daba (Antheraea mylitta), oak tasar (Antheraea proylei), and bivoltine mulberry (Bombyx mori) varieties. A decrease in filament linear density from the outer to the innermost layers was observed in all the varieties. Although the filament tenacity was found to increase in bivoltine mulberry cocoons from the outer to the inner layers, no such specific trend was observed for Daba cocoons. For oak tasar cocoons, it showed a marginal rise. A similar trend was observed for filament initial modulus also. The breaking extension of filament was constant for Daba cocoons, decreased for oak tasar cocoons and showed a rise followed by a fall for bivoltine mulberry cocoons from the first to the last layers. The residual sericin decreased marginally from the outer to the inner layer in the case of tasar cocoons. However, for mulberry cocoons it decreased rapidly initially up to the fourth layer and thereafter showed no change. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Combined effect of VA content and pH level of filler on properties of EPDM/SmBO3 and EPDM/ATO composites reinforced by three types of EVA
Authors: Su Jun , Chen Shuangjun , Zhang Jun , Xu Zhongzi 
Published: March 2010

AbstractThis study investigates the interaction of vinyl acetic (VA) content of ethylene‐vinyl acetate (EVA), pH level of Samarium borate (SmBO3), and Sb‐doped SnO2 (ATO) on reinforcement of peroxide‐cured ethylene‐propylene‐diene rubber (EPDM)/SmBO3 and EPDM/ATO composites. It was found that EVA could both reinforce mechanical properties of EPDM, and enhance fluidity of gum during processing. During vulcanization, the interaction of VA groups and pH value of filler particles can influence the crosslink density of EPDM composites. In alkaline EPDM/SmBO3/EVA, VA groups could hydrolyze to produce polyvinyl alcohol and reduce pH level of medium by consuming OH−. When dispersed in acidic EPDM/ATO/EVA, VA groups could generate polyunsaturated bonds and acetic acid during vulcanization. The double bonds could react with dicumyl peroxide (DCP) and then boost crosslink efficiency of EPDM composites. Moreover, acetic acid and reduction of pH value could make DCP decompose into ions, and lower crosslink density of EPDM composites. In addition to the contribution of crosslink density, EVA could crystallize in EPDM composites to reinforce EPDM composites. Electric properties of EPDM were also affected. Surface and volume resistivity of EPDM composites decreased with the rise of VA content. As for EPDM/SmBO3/EVA composites, the growth of VA groups could boost dielectric constant and loss, decrease dielectric strength, due to the enhancement of polarity and reduction of crosslink density. In terms of EPDM/ATO/EVA composites, the EPDM/ATO/EVA14 possesses the highest dielectric constant and loss, and the lowest dielectric strength, because of the competing effect of VA content and crosslink density. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermosensitive polyurethane film and finished leather with controllable water vapor permeability
Authors: Shi Huanhuan , Chen Yi , Fan Haojun , Xiang Jun , Shi Bi 
Published: March 2010

AbstractThree types of water based polyurethane (PU), i.e. one ordinary elastomeric polyurethane (EPU) and two thermosensitive polyurethane (TSPU), were synthesized and applied in leather finishing. Differential scanning calorimetry, positron annihilation lifetimes (PAL), water swelling, and water vapor permeability (WVP) were measured to evaluate how the structure of the synthesized PU and the temperature influenced the WVP of the PU finished leather. In contrast to EPU, TSPU(b) with a glass transition reversible phase and TSPU(c) with a crystal transition reversible phase showed an obvious phase separation structure and a phase transition in the normal wearing temperature range. PAL study indicated that when the temperature was higher than the designed phase transition temperature, the ortho‐positronium lifetime (τ3) and the average radius (R) of free volume of TSPU showed dramatic changes, whereas τ3 and R of EPU remained unchanged. The water swelling and WVP of TSPU finished leather were found to depend on the structure of the polymer and the temperature, and they gave different responses to temperature variation. When the temperature was higher than the designed phase transition temperature, a significant WVP increase from 3800 g/(m2 24 h) to 7830 g/(m2 24 h) for TSPU(b) finished leather and from 4100 g/(m2 24 h) to 9450 g/(m2 24 h) for TSPU(c) finished leather were observed. Whereas EPU finished leather showed low WVP, and increased slightly as temperature increased. Phase transition accompanying a significant change in WVP can be used to develop “smart leather” with controllable water vapor permeability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and antidehydration of interpenetrating polymer network hydrogels based on 2‐hydroxyethyl methacrylate and N‐vinyl‐2‐pyrrolidone
Authors: Wang Jingjing , Sun Fuqian , Li Xinsong 
Published: March 2010

AbstractThis work reports the preparation of 2‐hydroxyethyl methacrylate (HEMA)/N‐vinyl‐2‐pyrrolidone (NVP) interpenetrating polymer network (IPN) hydrogels by UV‐initiated polymerization in the presence of free radical photoinitiator Darocur 1173 and cationic photoinitiator 4,4′‐dimethyl diphenyl iodonium hexafluorophosphate. The polymerization mechanism was investigated by the formation of gel network. The structure and morphology of the HEMA/NVP IPN hydrogels were characterized by fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The results showed that the IPN gels exhibited homogeneous morphology. The dehydration rates of HEMA/NVP IPN hydrogels were examined by the gravimetric method. The results revealed that the hydrogels had a significant improvement of antidehydration ability in comparison with poly(2‐hydroxyethyl methacrylate)(PHEMA) hydrogel embedded physically with poly(N‐vinyl‐2‐pyrrolidone)(PVP). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Investigation on properties of new fluorine‐ and silicon‐modified UV‐cured epoxy methacrylate resin
Authors: Tang Chunyi , Liu Weiqu 
Published: March 2010

AbstractPhotosensitive organofluorine and organosilicon play a key role in improving the properties of UV‐curing coating materials. In this study, by using 2,2,3,4,4,4‐hexafluorobutyl methacrylate (HFMA) and a synthesized side methacryloxy group polysiloxane (MAPS) as modifying materials and bisphenol‐A epoxy methacrylate (BEMA) as matrix, respectively, a innovative UV‐curing system, BEMA/HFMA/MAPS composite system was developed. Through UV‐cure process, a series of BEMA/HFMA, BEMA/MAPS, and BEMA/HFMA/MAPS cured composite films with different proportions were successfully obtained. It was found that HFMA monomer was helpful for the reduction of the surface energy of the UV‐cured composite films and the enhancement of their water resistance property. Without HFMA in BEMA matrix, MAPS could facilitate the improvement of the properties of BEMA/MAPS cured films, and the presence of MAPS in BEMA/HFMA/MAPS system could significantly decrease the surface energy of the cured films to 22.1 mJ/m2 and improve their thermal stabilities and water resistance properties by measurements, contact angle, TGA, DSC, and water resistance. To the SEM observation, HFMA and MAPS were well distributed in the cured films in favor of their excellent performances. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co(III) complex mediated microwave‐assisted synthesis of PAN
Authors: Biswal Trinath , Samal Ramakanta , Sahoo Prafulla K. 
Published: March 2010

AbstractFree radical polymerization of acrylonitrile (AN) is efficiently, easily, and quickly achieved in the presence of Co(III) complex, [Co(III) en3]Cl3 and ammonium persulphate (APS) in domestic microwave oven. The rate of polymerization depends on the power and time of microwave irradiation, and is independent of the technique employed (periodic or continuous irradiation). The conversion of monomer to the polymer was mostly excellent in gram scale. Irradiation at low power and time produced more homogeneous polymers with high molecular weight and low polydispersity when compared with the polymer formed by conventional heating method. The interaction of reacting components was monitored by UV–visible spectrometer. The average molecular weight was derived by GPC and viscosity methods and sound velocity by ultrasonic interferometer. The uniform and reduced molecular size was characterized by transmission electron microscopy, the diameter of PAN particles being in the range 220–250 nm in microwave and 120–530 nm in conventional heating methods. From the kinetic results, the rate of polymerization (Rp) was expressed as

© 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010