bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement and prediction of adsorption equilibrium for a H2/N2/CH4/CO2 mixture
Authors: Wu Jiaquan , Zhou Li , Sun Yan , Su Wei , Zhou Yaping 
Published: March 2007

AbstractAdsorption equilibrium data for the pure gases, H2, N2, CH4, CO2, and a H2/N2/CH4/CO2 mixture on activated carbon JX101 were collected by static and dynamic methods, respectively. The tested range covered temperatures of 283–328 K and pressures up to 30 × 105 Pa. The difference in the adsorption mechanisms between the super‐ and sub‐critical components was considered for both correlation of pure gas adsorption and prediction of multicomponent adsorption equilibrium. The surface heterogeneity, interaction among the adsorbed molecules, and the non‐ideal behavior of the adsorbed phase were also accounted for. As a consequence, the pure gas adsorption data were accurately correlated, and the multicomponent adsorption equilibrium was satisfactorily predicted by a proposed model. Applicability of the new model was verified with the present experimental data and with literature values. In all cases, the new model produced better agreement between the predicted data and the experimentally measured data than previous models. This indicates that the new model is probably applicable to predict the adsorption equilibrium of gas mixtures either partially or totally composed of supercritical gases. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Chemische Strategien für den Aufbau molekularer Logikelemente zur Addition und Subtraktion
Authors: Pischel Uwe 
Published: March 2007

AbstractMolekulare und supramolekulare Logikgatter sind Kandidaten für die Realisierung von Computern auf der Nanoebene. Heutzutage können alle gebräuchlichen Logikoperationen mit molekularen Funktionseinheiten auf chemischer Basis nachgeahmt werden. Ein weiterer Schritt in Richtung molekularer Systeme mit verbesserten Logikkapazitäten ist die Addition oder Subtraktion von binären Ziffern. Dieser Kurzaufsatz beschreibt aktuelle Entwicklungen auf dem Weg zu diesem Ziel, einschließlich bioinspirierter Systeme, die auf DNA oder Enzymen basieren. Weiterhin werden chemische molekulare Logikgatter kritisch im Hinblick auf ihr Verhältnis zu alternativen Konzepten diskutiert.
Synthesis of polyacrylonitrile via reverse atom transfer radical polymerization initiated by 1,1,2,2‐tetraphenyl‐1,2‐ethanediol/FeCl3/triphenylphosphine
Authors: Hou Chen , Ying Liang 
Published: March 2007

AbstractFeCl3 coordinated by triphenylphosphine was first used as the catalyst in the 1,1,2,2‐tetraphenyl‐1,2‐ethanediol‐initiated reverse atom transfer radical polymerization of acrylonitrile. A FeCl3/triphenylphosphine ratio of 0.5 not only gave the best control of the molecular weight and its distribution but also provided a rather rapid reaction rate. The rate of polymerization increased with increasing polymerization temperature, and the apparent activation energy was calculated to be 62.4 kJ/mol. When FeCl3 was replaced with CuCl2, the reverse atom transfer radical polymerization of acrylonitrile did not show prominent living characteristics. To demonstrate the active nature of the polymer chain end, the polymers were used as macroinitiators to advance the chain‐extension polymerization in the presence of a CuCl/2,2′‐bipyridine catalyst system via a conventional atom transfer radical polymerization process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4041–4045, 2007
Mechanical and thermal properties of toughened polypropylene composites
Authors: Houshyar S. , Shanks R. A. 
Published: March 2007

AbstractThe mechanical, thermal, and structural properties of a new flexible composite containing polypropylene fiber (PP) in a random poly(propylene‐co‐ethylene) (PPE) matrix with ethylene–propylene elastomer (EP) was investigated with emphasis on the effect of EP elastomer concentration. The intrinsic composition of the composites, toughening of the matrix with EP and the fiber–matrix interface determined the properties of the composites. Through the incorporation of EP elastomer into the polypropylene–poly (propylene‐co‐ethylene) (all‐PP) composite, tensile and storage modulus (E′) decreased, flexural modulus and loss modulus (E″, damping) increased slightly to 0.15 EP and then decreased. There was an increase in impact resistance for the toughened composites, with about 100% increase in comparison with an untoughened all‐PP composite. The composition corresponding to 0.20 weight fraction EP gave optimum impact and mechanical properties. Creep resistance of the composite decreased with increasing EP content, but recovery showed an increase with increasing EP content up to 0.20. Fracture surfaces of composites after impact tests were studied with scanning electron microscopy. Moreover, the use and limitation of theoretical equations to predict the tensile and flexural modulus of the flexible PP composite is discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Observation for mechanical property variations of single polymer particles
Authors: Kim Dong Ok , Jin Jeong Hee , Shon Won Il , Oh Seok Heon 
Published: March 2007

AbstractMonodisperse polymer particles were prepared via conventional microsuspension polymerization or one‐step seeded polymerization, using 1,6‐hexanedioldiacrylate or its mixture with ethylene glycol dimethacrylate (EGDMA) as crosslinking monomer and poly(methyl methacrylate) synthesized by soap‐free polymerization as seed particles. For the study, the effects of the ratio of the absorbed monomer or monomer mixture to the seed polymer particles (swelling ratio), the ratio of EGDMA in absorbed monomer mixture, the dosage of initiator, polymer particle structure, and the electroless Ni plating on the mechanical properties of polymer particles, such as recovery rate, K‐values, breaking strength, and breaking displacement were investigated using micro compression test. It was observed that monomer swelling ratio influenced only on breaking strength, whereas EGDMA ratio in monomer mixture, dosage of initiator, polymer structure and electroless Ni plating did on both K‐values and breaking strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Photoinitiated RAFT polymerization in the presence of trithiocarbonate
Authors: Ran Rong , Yu You , Wan Tao 
Published: March 2007

AbstractA reversible addition–fragmentation chain transfer agent, S,S′‐bis(α,α′‐dimethyl‐α″‐acetic acid)trithiocarbonate (TTCA), for free radical polymerization was synthesized. The photopolymerizations (Szwarc et al., J Am Chem Soc 1956, 78, 2656) of styrene (St) and butyl acrylate in the presence of TTCA were carried out at room temperature, and the results showed that both ln[M]0/[M] and molecular weight were linearly increased with monomer conversion, while the molecular weight distribution became slightly narrower as monomer conversion increased. Moreover, the calculated molecular weight of PSt and PBA agreed quite well with the experiment values determined by gel permeation chromatography and NMR. These experimental data demonstrated characteristics of controlled/living photopolymerizations. In addition, the triblock copolymer, PSt‐PBA‐PSt, with very good control over molecular weight and narrow polydispersity (PDI =1.12–1.14), was successfully prepared using PStSC(S) SPSt as macrophotoinitiator under UV irradiation at room temperature. Both FTIR and 1H NMR spectra data indicated the presence of trithiocarbionate structure in PSt. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Gel formed during the solid‐state graft copolymerization of styrene and spherical polypropylene granules. I. Influence of reaction conditions on the gelation and its mechanism
Authors: Zhang Letian , Fan Zhiqiang , Deng Qingtian , Fu Zhisheng 
Published: March 2007

AbstractGraft copolymers of polystyrene (PSt) with spherical polypropylene (PP) granules were synthesized by solid‐state reaction. In the copolymerization as a by‐product some gel was formed. The effects of the amount of free radical initiator, feed ratio of St monomer, species of free radical initiator, and composition of the spherical polyolefin granules on the grafting degree of PSt and the gelation were studied. It is found that larger amount of initiator used, and higher feed ratio of St monomer lead to a higher grafting degree and higher content of gel. During the cross‐link reaction process, both styrene and free‐radical participate in the reaction that discloses the reason of the increment of gel with the increment of styrene consumption or initiator consumption. Using PPR, which is a random copolymer of 95.1 mol % propylene units and 4.9 mol % ethylene units, as grafting matrix, higher grafting degree and higher content of gel can be reached than that using isotactic PP as grafting matrix. Using tert‐butyl peroxy benzoate (TBPB) as initiator, under the same conditions there were more PSt grafted to the spherical PP granules and more gel formed than that using benzoyl peroxide (BPO) as initiator. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3682–3687, 2007
Precipitation polymerization of acrylamide with quaternary ammonium cationic monomer in potassium carbonate solution initiated by plasma
Authors: He Yangang , Li Gang , Yang Fang , Yu Xueqing , Cui Yingjun , Ren Fengxia 
Published: March 2007

AbstractPrecipitation polymerization of 2‐(methacryloyloxyethyl) trimethyl ammonium chloride (DMC)‐co‐acrylamide (AM) [poly(AM‐DMC)] has been successfully performed in potassium carbonate (K2CO3)‐water media by plasma initiation. K2CO3 solution was selected because not only the higher solubility of AM and DMC comparing with that of poly(AM‐DMC), but the higher intrinsic viscosity of poly(AM‐DMC) could be obtained. A set of experiments was performed using different K2CO3 concentration (from 50 down to 10% (w/w)), thus the precipitation architecture was not obtained below 20% (w/w). And particles size, particles size distribution (7–120 μm), and intrinsic viscosity of poly(AM‐DMC) (ranging up to 455 cm3/g) were also summarized in this article. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4060–4067, 2007
Photografting polymerization of polyacrylamide on PHBV films (I)
Authors: Ke Yu , Wang Yingjun , Ren Li , Lu Ling , Wu Gang , Chen Xiaofeng , Chen Jingdi 
Published: March 2007

AbstractPhotografting polymerization of polyacrylamide (PAM) onto poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) films using benzophenone as photoinitiator was studied. The morphology and structure of the grafted PHBV film were characterized by Fourier transformed infrared spectroscopy (FTIR) with attenuated total reflectance (ATR) and scanning electron microscope (SEM) with energy dispersive X‐ray spectrometer (EDX). The grafting percentage and grafting efficiency of the grafted PHBV film went up with the increase of acrylamide concentration and irradiation time. It was observed that photografting polymerization of PAM was not only limited to the film surface, but also in situ occurred inside the film to form the pore microstructure. Sheep bone marrow stromal cell studies showed that MSCs cells attachment efficiency on the grafted PHBV films increased and cells grew well. These results demonstrated the potentiality of PAM‐photografting PHBV in medical applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104, 4088–4095, 2007
Microwave accelerated synthesis and characterization of poly(acrylamide)
Authors: Singh Vandana , Tiwari Ashutosh , Kumari Premlata , Sharma Ajit K. 
Published: March 2007

AbstractPoly(acrylamide) (PAM) was efficiently synthesized under microwave (MW) irradiation using catalytic amount of potassium persulfate. The synthesis does not require any inert atmosphere and could be accomplished in very short time. Microwave power, exposure time, concentration of persulfate, and concentration of the acrylamide were varied to optimize the polymerization in terms of the % conversion (%C). The maximum %C that could be achieved was in 98.5%. The average molecular weight of the synthesized PAM samples ranged from 4.11 × 104 to 1.30 × 105, depending upon the MW power used for their synthesis. The representative PAM was characterized by Fourier transform‐infrared, SEM, and X‐ray diffraction studies. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3702–3707, 2007
Effect of posttreatment on morphology and properties of poly(ethylene‐co‐vinyl alcohol) microporous hollow fiber via thermally induced phase separation
Authors: Lv Rui , Zhou Jing , Du Qiangguo , Wang Haitao , Zhong Wei 
Published: March 2007

AbstractPoly(ethylene‐co‐vinyl alcohol) (EVOH) hollow fiber membranes were prepared by thermally induced phase separation (TIPS) process. Water, methanol, and acetone were used to extract the diluents in the fibers, respectively. Bigger shrinkage of fibers during extractant evaporation was observed when water or methanol was used. Their interaction parameters with EVOH were calculated via Hansen solubility, respectively. The mechanism of hollow fiber volume shrinkage was discussed. It was found that affinity of the extractant with polymer was the critical factor except for the surface tension of extractant. Through the X‐ray diffraction analysis during extraction and evaporation, the crystallization behavior of the polymer was studied. From the SEM photos, it was observed that the volume shrinkage was derived from the collapse of porous structure. The fiber sample extracted by acetone had similar morphology with the sample freeze‐dried. The gas and water permeability were also measured and the results were coincident with the morphology of fibers and shrinkage data. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4106–4112, 2007
Heat sealability of laminated films with LLDPE and LDPE as the sealant materials in bar sealing application
Authors: Yuan Cheng See , Hassan Azman , Ghazali Mohd Imran Hj , Ismail Ahmad Fauzi 
Published: March 2007

AbstractThe heat sealability of laminated films with linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) as the sealant materials was investigated. A laboratory heat sealer was used to study the response of laminated films to temperature, time, and pressure. Platen temperature was confirmed as primary factor in controlling heat‐seal strength. Dwell time must be sufficiently long to bring the interfacial temperature to a desired level. When the desired heat‐seal strength has been achieved, further increase of dwell time did not improved heat‐seal strength. Platen pressure had little effect above the level required to flatten the materials for good contact. Bar sealing process window for each sample were developed. The optimum combination of platen temperature and dwell time for each laminated film can be obtained in the respective process windows. Strength of heat‐seal and its failure modes are closely related. Plateau initiation temperature closely corresponds to the final melting point of sealant materials. Relatively higher platen temperature was required to seal laminated films with lower thermal conductance. Required dwell time corresponds closely to the heat flow rate of bar sealing process. Laminated films made from extrusion lamination process provided lower level of achievable heat seal strength when compared with the laminated films made from dry‐bond lamination process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3736–3745, 2007
Physicochemical properties of prepared ion‐exchangers from cellulose incorporated with different functional group
Authors: Nada A. M. A. , Adel Abeer M. 
Published: March 2007

AbstractBagasse raw material and bleached bagasse pulp were used to prepare carbamoyl ethyl and cyanoethyl cellulose which were converted to ion exchangers. The effect of crosslinking on the properties of the carbamoyl ethyl and cyanoethyl cellulose was investigated. The molecular structure of the produced resin was also studied via infrared spectroscopy. New bands were seen at 2252 cm−1 and a shoulder at 3140 cm−1, which are due to the cyano group (in cyanoethylated cellulose) and amino group (in the carbamoyl ethyl cellulose). Also, another band was appeared at 1715 cm−1, which is due to the carboxyl group, formed due to hydrolysis of cyanoethyl or carbamoyl ethyl cellulose. Thermal gravimetric analysis (TGA) of the produced resin was studied. The existence of both cyano group and carbamoyl group increased the resistance of cellulose towards the thermal treatment. The efficiency of the produced resin towards metal ions uptake from solution mixture (Cu, Ni, and Cr) was also studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Thermogravimetric analysis of chitosan
Authors: Hong Peng‐Zhi , Li Si‐Dong , Ou Chun‐Yan , Li Cheng‐Peng , Yang Lei , Zhang Chao‐Hua 
Published: March 2007

AbstractThe thermal degradation of chitosan at different heating rates B in nitrogen was studied by thermogravimetric analysis. The results indicate that the thermal degradation of chitosan in nitrogen is a one‐step reaction. The degradation temperatures increase with B. Experimentally, the initial degradation temperature (T0) is (1.049B + 326.8)°C; the temperature at the maximum degradation rate, that is, the peak temperature on a differential thermogravimetry curve (Tp), is (1.291B + 355.2)°C; and the final degradation temperature (Tf) is (1.505B + 369.7)°C. The degradation rates at Tp and Tf are not affected by B, and their average values are 50.17% and 72.16%, respectively, the maximum thermal degradation reaction rate, that is, the peak height on a differential thermogravimetry curve (Rp), increases with B. The relationship between B and Rp is Rp = (1.20B + 2.44)% min−1. The thermal degradation kinetic parameters are calculated with the Ozawa–Flynn–Wall method. The reaction activation energy (E) and frequency factor (A) change with an increasing degree of decomposition, and the variable trends of the two kinetic parameters are similar. The values of E and A increase remarkably during the initial stage of the reaction, then keep relatively steady, and finally reach a peak during the last stage. The velocity constants of the thermal degradation vary with the degree of decomposition and increase with the reaction temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
The influence of latex blend composition on crosslinking and mechanical properties
Authors: Boyars Brian , Daniels Eric S. , Storer Robert , Klein Andrew 
Published: March 2007

AbstractModel reactive latices were synthesized by semicontinuous emulsion copolymerization of n‐butyl methacrylate and acetoacetoxyethyl methacrylate or dimethylaminoethyl methacrylate. The two functional latices were then blended in various ratios to study the influence of blend composition on crosslinking and mechanical properties of the resulting films. Crosslinking was quantified through swelling measurements. It was found that the crosslink density increased with increasing amounts of acetoacetoxy‐functional polymer. In addition, the crosslink density exhibited two maxima, at 30/70 and 70/30 (acetoacetoxy‐functional latex/amino‐functional latex) blend compositions. The mechanical properties of the films were quantified by dynamic mechanical analysis (DMA). It was shown that optimal mechanical properties occurred when the particles packed most efficiently at the 30/70 and 70/30 blend compositions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3774–3779, 2007
Surface modification of nylon‐6 fibers for medical applications
Authors: Shalaby S. E. , Al‐Balakocy N. G. , Abo El‐Ola S. M. 
Published: March 2007

AbstractHydroxyethylmethacrylate (HEMA) is considered to be one of the important vinyl monomers. The ability of polyhydroxyethyl‐methacylate (PHEMA) graft sites to consecutive chemical modification makes the use of nylon‐6 fibers grafted with PHEMA a feasible bed for immobilization of a wide range of biologically active reagents, specially enzymes, drugs, cells, and immunadsorbents. Stemming from the above discussions, in this article, the graft copolymerization of HEMA onto modified nylon‐6 fibers containing Polydiallyldimethylammonium chloride (PDADMAC) in the presence of Cu2+–K2S2O8 as a redox initiating system was carried out, with very high rate and almost without homopolymer formation. The factors affecting the grafting reaction (monomer, K2S2O8 and cupric ion concentrations, the amount of PDADMAC as well as the reaction temperature) were studied. Kinetic investigation revealed that the rate of grafting (Rp) of HEMA onto modified nylon‐6 fibers is proportional to [HEMA]1, [CuSO4.5H2O] 0.7, [PDADMAC]0.4, and [K2S2O8]1.4. The overall activation energy was calculated (71 KJ/mol). The fine structure, surface topography, thermal and electrical properties of parent and grafted nylon‐6 fibers were investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3788–3796, 2007
Electrical properties of modified‐grafted polypropylene
Authors: El‐Sawy Naeem M. , Khalil Magda M. I. , El‐Shobaky Gamil A. 
Published: March 2007

AbstractThe electrical properties of polypropylene (PP), grafted polypropylene (PP‐g‐PVP), and modified‐grafted PVP with α‐cyano‐β‐(2‐thienyl) crotononitrile were investigated. Also, the electrical characteristic of the modified‐grafted PVP subjected to γ‐irradiation (60 kGy) was studied. The results show that the σ of trunk polymer undergoing different degree of grafting generally increases as function of the grafting yield. The grafting yield between 64.1 and 149% resulted in a progressive decrease in ΔEσ value. Inclusion of sulfur‐containing substrate in different films, having various grafting yields, leads to both increase and decrease in σ values. A significant increase in σ values is observed upon inclusion of sulfur‐containing substrate having maximum grafting yield (149%). These changes are accompanied by fluctuation in σ values. The exposure of sulfur‐containing substrate in grafting film to a dose of 60 kGy results in a significant decrease in ΔEσ values for the films undergoing a grafting yield between 64.1 and 149%. The observed changes in ΔEσ of different films investigated could be attributed mainly to corresponding changes in σ values. The observed improvement in electrical properties is mainly because of possible increase in concentration of charge carrier and/or their mobilities. The scanning electron micrographs of some selected films show significant changes in the morphology of the films investigated due to changing the grafting yield, inclusion of sulfur‐containing substrate, and exposure to γ‐irradiation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3797–3803, 2007
Polymerization of N‐vinylcarbazole by multiwalled carbon nanotube
Authors: Maity Arjun , Biswas Mukul 
Published: March 2007

AbstractN‐vinylcarbazole (NVC) was polymerized in bulk or in toluene in presence of multiwalled carbon nanotube (MWCNT) without any extraneous catalyst. The formation of polyN‐vinylcarbazole (PNVC) was endorsed by striking agreement of FTIR, fluorescence and UV‐visible spectroscopic, thermogravimetric stability, differential scanning calorimetry, and dielectric characteristics of this polymer with the corresponding literature data for authentic PNVC samples prepared by free radical or carbocationic initiation. The polymerization was supposed to be initiated by a single electron transfer between N lone pair of NVC and the electron deficient MWCNT moieties. While PNVC homopolymer is nonconducting (10−12 to 10−16 S/cm), a composite of PNVC with MWCNT isolated from the polymerization system showed high dc conductivity varying from 1.3 to 33 S/cm depending upon the extent of MWCNT loading in the composite. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4121–4126, 2007