bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical properties, stress‐relaxation, and orientation of double bubble biaxially oriented polyethylene films
Authors: Bobovitch A. L. , Tkach R. , Ajji A. , Elkoun S. , Nir Y. , Unigovski Y. , Gutman E. M. 
Published: March 2006

AbstractBiaxially oriented linear low density polyethylene (LLDPE) films were produced using the double bubble process with different machine direction (MD) orientation levels and the same transverse direction (TD) blow‐up ratio. Their mechanical behavior was characterized in terms of the tensile strength and tear resistance. The viscoelastic behavior of oriented films was studied using dynamic‐mechanical thermal analysis (DMTA). The microstructure and orientation were characterized using microscopy, X‐ray diffraction pole figures, and birefringence. The results indicate that MD ultimate tensile strength increases and the TD one decreases with MD stretching ratio. Tear propagation resistance, in general, remained mainly constant in TD and decreased in MD, as the draw ratio was increased. The morphology analyses exhibit a typical biaxial lamellar structure for all samples with different lamellar dimensions. Orientation of c‐axis in crystalline phase, molecular chain in amorphous phase along MD increased with draw ratio. In most crystals, a‐axis was located in the normal direction (ND) and the b‐axis in the ND–TD plane. A good correlation was observed between c‐axis orientation factor and MD mechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3545–3553, 2006
Oxidative copolymerization between toluidine and vinyl acetate
Authors: Li Xin‐Gui , Dong Zhi‐Qing , Huang Mei‐Rong , Shao Hui‐Li , Hu Xue‐Chao 
Published: March 2006

AbstractA series of copolymers between o‐toluidine (OT) and vinyl acetate (VA) was synthesized by a chemically oxidative polymerization, which was carried out by three different methods: suspension solution precipitation, emulsion and inverse emulsion copolymerizations by using iron trichloride, and ammonium persulfate as oxidant. The progress in the copolymerization, polymerization yield, structure, and properties of the resulted OT/VA copolymers were systematically characterized by solution potential/temperature monitor, laser particle size, FTIR, UV–vis, and thermogravimetry techniques. The results show that the diameter, spectral characteristics, solubility, film formability, electrical conductivity, and thermostability of the virgin polymer particles formed exhibit a nonmonotonic dependence on the OT/VA ratio, suggesting an occurrence of an oxidative copolymerization between OT and VA monomers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3562–3573, 2006
Possibilities of collagen adsorption on some polymeric matrices based on styrene copolymers
Authors: Elena Nita Loredana , Chiriac Aurica P. , Vasile Cornelia 
Published: March 2006

AbstractSeven matrices based on polystyrene and styrene copolymers, with acrylic and methacrylic acid, acryl‐ and methacrylamide, and acrylonitrile and maleic anhydride, are tested in respect of their capacity of collagen adsorption. The aim of the study is to correlate the collagen coupling capacity by the nature of the monomers and the ability of functional groups to obtain biomaterials. The prepared vinylic polymers are relatively hydrophobic. These hydrophobic properties, together with the large mesh interstices, hinder smooth‐cell seeding. In contrast, collagen offers the advantage of specific cell interactions and hydrophilicity. Therefore, synthetic polymers and collagen have been hybridized to combine their advantages. The biocompatibilization process consists of physical immobilization of the protein onto the synthesized matrice surfaces. The content of the adsorbed protein was correlated with the conditions of capture, solution pH, and sorption temperature, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3554–3561, 2006
Thermal stability of polypropylene/carbon nanofiber composite
Authors: Chatterjee Arobindo , Deopura B. L. 
Published: March 2006

AbstractThermal stability of polypropylene and carbon nanofibre composite system has been studied using Thermogravimetric Analysis, Limited Oxygen Index (LOI), Flammability, Calorimetry, and Oxidation Induction Time techniques. Definite improvement in thermo‐oxidative stability of the composite system has been observed. Improvement in LOI and a distinct change in the burning characteristics suggest a reduction in potential fire hazards. The nanocomposite system will have enhanced anti‐ageing characteristics and require more stringent conditions for the initiation of burning and the ultimate impact of burning will be less. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3574–3578, 2006
Fluorinated‐plasma modification of polyetherimide films
Authors: Kaba Meriyam , Essamri Azzouz , Mas Andre , Schue Francois , George G. A. , Cardona F. , Rintoul L. , Wood B. J. 
Published: March 2006

AbstractUltem 1000 polyetherimide films prepared by cast‐evaporating technique were covered with a 1H,1H,2H‐tridecafluoro‐oct‐1‐ene (PFO) plasma‐polymerized layer. The effects of the plasma exposure time on the surface composition were studied by X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and surface energy analysis. The surface topography of the plasma layer was deduced from scanning electron microscopy. The F/C ratio for plasma‐polymerized PFO under the input RF power of 50 W can be as high as 1.30 for 480 s and ∼0.4–2 at % of oxygen was detected, resulting from the reaction of long‐lived radicals in the plasma polymer with atmospheric oxygen. The plasma deposition of fluorocarbon coating from plasma PFO reduces the surface energy from 46 to 18.3 mJ m−2. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3579–3588, 2006
Synthesis and characterization of radiation grafted copolymer for removal of nonionic organic contaminants
Authors: Sokker H. H. , Ghaffar A. M. Abdel , Nada A. M. A. 
Published: March 2006

AbstractNonionic organic contaminants such as phenol, benzene, and toluene from contaminated wastewater on laboratory scale can be effectively sorbed by cellulosic wood pulp sheet incorporated with three polar functional groups. The synthesis was carried out by graft copolymerization reaction of N,N‐dimethylaminoethylmethacrylate with methacrylic acid onto wood pulp. The preparation conditions at which the grafting process proceeds homogeneously are determined. Characterization and some selected properties of the original and grafted wood pulp were evaluated using FTIR and scanning electron microscope, also, the removal of phenol, benzene, and toluene on laboratory scale was investigated by using gas chromatography. It was found that phenol shows the highest removal percent than that of benzene and toluene. The efficiency of removal of the nonionic contaminants is found to be 97%, which shows a great promise for its applicability in the removal of organic contaminates from wastewater. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3589–3595, 2006
Preparation and characterization of novel cationic copolymer hydrogels with pH sensitivity and thermosensitivity
Authors: Guo Jin Tang , Li Ling , Li Xiong Yong , Zhu Jun Li 
Published: March 2006

AbstractCationic hydrogels were synthesized through the copolymerization of N‐isopropylacrylamide and dimethylaminoethylmethacrylate. N,N′‐Methylenebisacrylamide was used as a crosslinking agent, and sodium bisulfite/ammonium persulfate was used as an initiator. The equilibrium and dynamic swelling properties were investigated to reveal the pH sensitivity and thermosensitivity of the hydrogels. The conclusion was drawn that the prepared cationic hydrogels demonstrated critical sensitivity at 37°C and pH 7.0–8.0 and that the stronger the acidity was of the buffered solution, the shorter the equilibrium swelling time was of the hydrogels. Drug‐release experiments in vitro were carried out at 37°C (close to body temperature), at pH 1.4 (close to the pH of the stomach), and at pH 7.4 (close to the pH of the intestine). The release results indicated that the drug (chloramphenicol) was released more rapidly from the prepared hydrogel in a pH 1.4 buffered solution than in a pH 7.4 one, and this was consistent with the results predicted from the experiments of the swelling kinetics. Moreover, the drug‐release process was confirmed by scanning electron micrographs of the hydrogels embedded with chloramphenicol. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3602–3608, 2006
Microstructure and wear properties of plasma‐sprayed aluminum–silicon–polyester coatings
Authors: Öksüz Mustafa , Yıldırım Hüseyin , Erturan Seyfettin 
Published: March 2006

AbstractPowder coatings, which are made by plasma‐spraying processes, are being used in industrial applications because of their wear resistance, chemical resistance, and high impact strength even at low service temperatures. These factors increase the importance of plastic and plastic‐based coatings in industrial applications. In this study, an aluminum–silicon–polyester‐based composite coating was applied by plasma‐spraying processes with and without an intermediate bond coat (Ni–Al). The effects of the coating thickness, intermediate bond coat, and processes parameters on the microstructure and wear properties of the coating were studied experimentally. The wear properties of the coatings were determined according to ball‐on‐disk procedure. The microstructures of the coating were examined by optical microscopy and scanning electron microscopy. The results indicated that the plasma‐spraying current and thickness had a strong influence on the wear resistance and microstructural properties of the aluminum–silicon–polyester coating. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3609–3614, 2006
Thermal and surface characterization of plasticized starch polyvinyl alcohol blends crosslinked with epichlorohydrin
Authors: Sreedhar B. , Chattopadhyay D. K. , Karunakar M. Sri Hari , Sastry A. R. K. 
Published: March 2006

AbstractStarch‐polyvinyl alcohol (PVA) blends in 2:8 wt % were prepared with various plasticizers such as polyethylene glycol (PEG‐200, PEG‐400) and glycerol. The crosslinking of starch‐PVA blends by epichlorohydrin was carried out in the presence of a plasticizer in situ. The obtained films were analyzed by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), dynamic mechanical and thermal analysis (DMTA), and X‐ray photoelectron spectroscopy (XPS), and remarkable changes in thermal stability and glass‐transition temperature have been observed on plasticizing and crosslinking in different concentrations. Different kinetic models such as Coats–Redfern, Broido, Friedman, and Chang were used to calculate the kinetic parameters of thermal decomposition. The results suggest that the thermal stability and activation energy of thermal decomposition passes through maxima at a critical concentration of plasticizer and increases with increasing crosslinker concentration. High‐resolution C 1s XPS analysis was used to provide a method of differentiating the presence of various carbons associated with different environment in the films. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 25–34, 2006
Preparation of copolymer of L‐aspartic acid and L‐glutamic acid
Authors: Rui Zhang , Tianwei Tan 
Published: March 2006

AbstractIn this article, a new copolymer of L‐aspartic acid and L‐glutamic acid, which may be a biodegradable high molecular polymer and can be used more widely in many areas, was synthesized. The conditions of preparation, such as catalyst, reaction time, reaction temperature, the amount of catalyst, the times of adding catalyst, and the molar ratio of L‐aspartic acid to L‐glutamic acid, were optimized. The copolymer was characterized by 13C NMR, infrared spectroscopy, and X‐ray diffractometer. The molecular weight was determined by GPC. The result indicated that production yield, purity of product, and molecular weight of product increased with amount of catalyst and molar ratio of L‐aspartic acid to L‐glutamic acid increasing. The best condition of preparation was the following: reacting 2–4 h at the temperature of 180–200°C. The product yield with the molecular weight 13,000.00 reached 63.2% and the purity of product was 96.33% when the copolymerization was carried out at the temperature of 200°C under vacuum for 2 h. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3626–3633, 2006
Mechanical properties of composites from sawdust and recycled plastics
Authors: Najafi Saeed Kazemi , Hamidinia Elham , Tajvidi Mehdi 
Published: March 2006

AbstractMechanical properties of wood plastic composites (WPCs) manufactured from sawdust and virgin and/or recycled plastics, namely high density polyethylene (HDPE) and polypropylene (PP), were studied. Sawdust was prepared from beech industrial sawdust by screening to the desired particle size and was mixed with different virgin or recycled plastics at 50% by weight fiber loading. The mixed materials were then compression molded into panels. Flexural and tensile properties and impact strength of the manufactured WPCs were determined according to the relevant standard specifications. Although composites containing PP (virgin and recycled) exhibited higher stiffness and strength than those made from HDPE (virgin and recycled), they had lower unnotched impact strengths. Mechanical properties of specimens containing recycled plastics (HDPE and PP) were statistically similar and comparable to those of composites made from virgin plastics. This was considered as a possibility to expand the use of recycled plastics in the manufacture of WPCs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3641–3645, 2006
Rheological properties of high melt strength poly(ethylene terephthalate) formed by reactive extrusion
Authors: Forsythe J. S. , Cheah K. , Nisbet D. R. , Gupta R. K. , Lau A. , Donovan A. R. , O'Shea M. S. , Moad G. 
Published: March 2006

AbstractA reactive extrusion process was developed improving the rheological properties of PET via the coaddition of a dianhydride and polyol. Specifically, the coaddition of pyromellitic dianhydride (PMDA) with pentaerythritol resulted in a gel‐free polyester with superior melt strengths and viscosities compared to the addition of PMDA alone. The enhancement in rheological properties were dependent on the relative amounts of dianhydride and polyol with the resultant polyester structurally stable in the melt. These results are consistent with the formation of a hyperbranched polyester with long chain branches. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3646–3652, 2006
Preparation and properties of nanocomposite hydrogels containing silver nanoparticles by ex situ polymerization
Authors: Lee Wen‐Fu , Tsao Kai‐Tai 
Published: March 2006

AbstractA series of composite hydrogels containing silver nanoparticle used for bioadhesives were prepared from acrylic acid, poly(ethylene glycol) methyl ether acrylate, and silver nanoparticles through ex situ polymerization. Silver nanoparticles with a narrow size distribution were prepared by the reduction of a silver nitrate solution with ascorbic acid. The influence of the content of the silver nanoparticles in the hydrogels on the equilibrium swelling ratio, mechanical properties, electrical conductivity, and inactivation of Escherichia coli (E. coli) was investigated in this study. The results showed that the swelling ratios of the composite gels were reduced by silver nanoparticles in the gels but were not reduced with an increase in the content of silver nanoparticles. In addition, the crosslinking density and shear modulus of these hydrogels did not increase with an increase in the content of silver nanoparticles. The adhesive force of these hydrogels (the APECAg series) was not obviously changed. Finally, the initial rate of E. coli inactivation for the APECAg series hydrogels showed excellent antibacterial properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3653–3661, 2006
Graft copolymers and high‐molecular‐weight star‐like polymers by atom transfer radical polymerization
Authors: Masař Bohumil , Janata Miroslav , Látalová Petra , Netopilík Miloš , Vlček Petr , Toman Luděk 
Published: March 2006

AbstractGrafting of tert‐butyl acrylate (tBuA), methyl methacrylate (MMA), and styrene (St) monomers (M) by Cu(I)‐mediated ATRP from polystyrene (PSt) macroinitiator (Mn = 5620, polydispersity index, PDI = 1.12), containing initiating 2‐bromopropionyloxy groups (I) (bound to 34% of aromatic cores; 11 groups per backbone), was performed using conditions suitable for the respective homopolymerizations. The preparation of PSt‐g‐PtBuA in bulk using an initial molar ratio [M]0/[I]0 = 140 had a controlled character up to Mn = (132–148) × 103 (PDI = 1.08–1.16). With MMA and St and using the same [M]0/[I]0, preliminary experiments were made; the higher the monomer conversion, the broader was the distribution of molecular weight of the products. Graft copolymerizations of all these monomers at [M]0/[I]0 = 840 or 1680 were successfully conducted up to high conversions. Low‐polydispersity copolymers, with very long side chains, in fact star‐like copolymers, were obtained mainly by tuning the deactivator amount in the reaction mixture. (PSt‐g‐PtBuA, DPn,sc (DP of side chain) = 665, PDI = 1.24; PSt‐g‐PMMA, DPn,sc = 670, PDI = 1.43; PSt‐g‐PSt, DPn,sc = 324, PDI = 1.11). Total suppression of intermolecular coupling was achieved here. However, the low concentrations of initiator required long reaction times, leading sometimes to formation of a small amount (∼5%) of low‐molecular‐weight polymer fraction. This concomitant process is discussed, and some measures for its prevention are proposed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3662–3672, 2006
The morphology and property of ultra‐fine full‐vulcanized acrylonitrile butadiene rubber particles/EPDM blends
Authors: Zhang Liqun , Li Tie , Lu Yonglai , Tang Yuanwang , Qiao Jinliang , Tian Ming 
Published: March 2006

AbstractA novel UFNBRP/EPDM blend was prepared by compounding ultra‐fine full‐vulcanized acrylonitrile butadiene rubber particles (UFNBRP) with ethylene–propylene–diene monomer (EPDM) matrix. The morphology, dynamic property, and curing property of the blend were discussed in detail. TEM and SEM observations showed that, no matter how high the blend ratio of UFNBRP to EPDM matrix was, UFNBRP particles always kept being in the dispersion phase because of its extremely high viscosity resulting from self‐crosslinking, but were not dispersed as nanosize units, as expected. Dynamic properties, illustrated by DMTA, further demonstrated that two phases exhibited two separate glass transition temperatures, indicating distinct phase separation and weak phase interaction. Rubber processing analyzer results showed that inorganic filler as well as UFNBRP particles in EPDM matrix formed a network and blocked the flow properties of the compound. At the same time, the introduction of UFNBRP particles evidently affected the vulcanization of EPDM, when sulfur was used as a vulcanizing agent, and improved the mechanical properties of EPDM. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3673–3679, 2006
Alternatives for multiobjective optimization of a polymerization process
Authors: Curteanu Silvia , Leon Florin , Gâlea Dan 
Published: March 2006

AbstractThe optimal control policies for a polymerization process, particularly for batch free‐radical polymerization of methyl methacrylate, were determined using a multiobjective optimization technique. The process objectives considered in the optimization include monomer conversion, polydispersity index, polymerization degree, and total reaction time, weighted and combined in a scalar objective function. The decision variables were the initial concentration of the initiator and the temperature represented by isothermal steps. For solving the optimization problem, several methods based on sequential quadratic programming and a genetic algorithm were used and compared. Combining them into a hybrid method (the genetic algorithm provided the initial values for the traditional iterative method) led to the best results. The aims of this study were to develop an approach for optimizing the polymerization process and to describe alternatives for formulating and solving this problem, emphasizing the importance of user decision in choosing solutions based on technological criteria. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3680–3695, 2006
Compatibility of HDPE/postconsumer HDPE blends using compatibilizing agents
Authors: Ramírez‐Vargas E. , Sandoval‐Arellano Z. , Hernández‐Valdez J. S. , Martínez‐Colunga J. G. , Sánchez‐Valdés S. 
Published: March 2006

AbstractMechanical properties, molecular weight, X‐ray diffraction, and differential scanning calorimetry (DSC) characterization of blends of virgin high‐density polyethylene (HDPE) with two types of recycled material were investigated. The recycled came from urban plastic waste; one kind was only washed and grounded and the other was extruded and pelletized to remove most of contaminant particles. Starting with the 30/70 virgin/grounded recycled and 50/50 virgin/pelletized recycled blends the recycled content was increased in both blends and compatibilizing agents were used to increase the blend performance. A mixture of phenolic antioxidants and phosphite costabilizers under the name of Recycloblend™, ethylene vinyl acetate (EVA) copolymer, low‐density polyethylene (LDPE), and linear low density polyethylene (LLDPE) were used as compatibilizers. The effect of these additives and the recycled content on the performance of extrusion blow‐molded bottles was determined. The results suggest that blends of virgin/grounded recycled and virgin/pelletized recycled HDPE, in general, were not significantly different among each other and both had a quite similar behavior than the virgin HDPE when compatibilizing agents were used. The addition of compatibilizing agents yielded a material with properties similar to those for the virgin HDPE, helping to reduce the effect of polymers degradation on the rheological and mechanical behavior, with Recycloblend and LLDPE being the most effective for the blends with grounded recycled material, and LLDPE y EVA, for the blends with pelletized recycled. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3696–3706, 2006
Emulsifier‐free synthesis and self‐assembly of an amphiphilic poly(styrene‐co‐acrylic acid) copolymer
Authors: Yan Lifeng , Zhang Guangzao , Liu Guangming , Ji Jing , Li Wan 
Published: March 2006

AbstractA poly(styrene‐co‐acrylic acid) copolymer was synthesized by surfactant‐free polymerization with the assistance of power ultrasound in water. Fourier transform infrared, NMR, and differential scanning calorimetry measurements revealed that the copolymer was random. Atomic force microscopy and laser light scattering were used to investigate the self‐assembly of the copolymer, and it was found that the copolymer chains formed micelles or other self‐assemble structures in solution. Atomic force microscopy also indicated that the self‐assembled structures developed into nanospheres with a poly(acrylic acid)‐rich or polystyrene‐rich surface in a film, depending on the solvent used for the preparation of the film. In particular, a wheel‐like structure could resulted in a film when the copolymer film was prepared in a moist environment; it resulted from heterogeneous aggregates of poly(acrylic acid) at the rim of water bubbles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:3718–3726, 2006