bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rheological behavior of alginate solutions for biomanufacturing
Authors: Rezende Rodrigo Alvarenga , Bártolo Paulo Jorge , Mendes Ausenda , Filho Rubens Maciel 
Published: May 2009

AbstractThe rheological behavior of alginate solutions were investigated for the optimal design of a biomanufacturing system to produce alginate structures for tissue engineering. Its rheological properties were determined by a rheometer through rotational and oscillatory tests. Experimental results were used to model the alginate solutions characteristics. The findings suggest that alginate solutions undergo shear‐thinning effects with increasing shear rates. It is also possible to observe that its loss modulus is higher than the storage modulus ones being both modulus dependent upon the frequency, which is a typical characteristic of dilute solutions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Grafting polymerization of 2‐[3‐(2h‐benzotriazol‐2‐yl)‐4‐hydroxyphenyl]ethyl methacrylate on vinyltriethoxysilane‐treated cotton for the preparation of ultraviolet‐protective fabrics
Authors: Tragoonwichian Suchada , O'Rear Edgar A. , Yanumet Nantaya 
Published: May 2009

AbstractVinyltriethoxysilane was used to modify the surface of cotton to provide polymerizable vinyl groups on the fiber surface. An ultraviolet‐absorbing monomer, 2‐[3‐(2H‐benzotriazol‐2‐yl)‐4‐hydroxyphenyl]ethyl methacrylate, was polymerized on the vinyltriethoxysilane‐treated fabric to prepare ultraviolet‐protective cotton. The effects of the amounts of the solvent, silane coupling agent, and 2‐[3‐(2H‐benzotriazol‐2‐yl)‐4‐hydroxyphenyl]ethyl methacrylate on the surface morphology and ultraviolet‐protection factor of the treated cotton fabric were investigated. With a suitable process, poly{2‐[3‐(2H‐benzotriazol‐2‐yl)‐4‐hydroxyphenyl]ethyl methacrylate} was successfully coated onto the fabric, and it significantly reduced ultraviolet transmission through the fabric, resulting in a cotton fabric with excellent ultraviolet‐protection properties. The use of a silane coupling agent helped to ensure a polymer coating with good uniformity and good resistance to washing. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Surface modification of PET fibers with the use of β‐cyclodextrin
Authors: Voncina Bojana , Vivod Vera , Chen Wen‐Tung 
Published: May 2009

AbstractThe purpose of our research was to prepare nanoencapsulated PET textile materials, which would be used as odor carriers (underwear and bed sheets with aromatherapy activities) or would act as malodorous absorbers (absorption of cigarette smell). We grafted β‐cyclodextrin onto PET textile materials by using a polyfunctional reagent 1,2,3,4‐butanetetracarboxylic acid. To reduce the curing temperature of the reaction, catalysts such as sodium hypophosphite and cyanamide were used. We prepared nanoencapsulated polyester textile materials with increased adsorption capacity and with delayed release of volatile or active compounds. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Reduction in tactoid size as a means for reinforcing high‐density polyethylene/montmorillonite nanocomposites
Authors: Marega Carla , Causin Valerio , Marigo Antonio , Ferrara Giuseppe 
Published: May 2009

AbstractNanocomposites were prepared by adding montmorillonite clay to a high‐density polyethylene matrix. Their structure, morphology, thermal behavior, and physical– mechanical properties were studied. The filler did not alter much the structure and morphology of the matrix, with the exception of a disruptive effect on the lamellar stacks. The crystallization behavior, equilibrium melting temperature, and work of chain folding of the nanocomposites were also unaltered with respect to that of the PE base polymer. However, significant improvements in physical–mechanical properties were observed. The reason for this increase in performance was ascribed to the interaction between the filler and the matrix, especially because of a reduction in size of the original tactoids to stacks of just a few layers, albeit not intercalated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of magnesium methacrylate and zinc methacrylate on bond properties of thermal insulation material based on NBR/EPDM blends
Authors: Gao Guoxin , Zhang Zhicheng , Zheng Yuansuo , Jin Zhihao 
Published: May 2009

AbstractTo improve the bond property between thermal insulation composites and metal surface, magnesium methacrylate (MDMA) and zinc methacrylate (ZDMA) were added into NBR/EPDM blends, respectively. The results indicated that the dispersion of MDMA powder was very well and its content changes much smaller in the composites than that of ZDMA. As a result, with the dosage of MDMA increasing from 0 phr to 7 phr, the polarity of MDMA/composites was improved gradually due to the increasing of ionic crosslink density and the decreasing of contact angle. Therefore, the bond strength of the composites to metal increased continuously. And the failures of bonding samples were all in MDMA/composites. After adding ZDMA instead of MDMA into the rubber, however, ZDMA powder would agglomerate during being vulcanized. Therefore, the bond strength of the composites firstly increased slightly and then decreased sharply once ZDMA was over 2 phr, whereas the contact angle of ZDMA/composites is much lower than that of MDMA/vulcanizates. Moreover, all the bonding samples failed at the interface of metal. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Enzyme‐based hydrogels containing dextran as drug delivery carriers: Preparation, characterization, and protein release
Authors: Lai Junying , Fang Rui , Wang Li‐Qun , Tu Kehua , Zhao Changsheng , Qian Xiaoqian , Zhan Shulin 
Published: May 2009

AbstractNovel enzyme‐based hydrogels for drug delivery were prepared by combining dextran with 5,5′‐azodisalicylic acid using isophorone diisocyanate as the crosslinking agent. The structure of the resultant dextran/5,5′‐azodisalicylic acid hydrogels was determined by infrared spectra, and the properties of the hydrogels were characterized by swelling measurements and scanning electron microscopy analysis. It was found that changing the concentration of 5,5′‐azodisalicylic acid affected the crosslinking density of the hydrogels and resulted in significant differences in the water swelling property and degradability of the hydrogels. Compared with their degradability, the degradation of the hydrogels seemed to be more pronounced by azoreductase in cecum content medium than that by hydrolysis in phosphate buffer solution (PBS). Also, the release rate of the protein in cecum content medium was faster than that in PBS. Attributing to the results of the resultant hydrogels described earlier, it could be concluded that dextran/5,5′‐azodisalicylic acid hydrogels could be used as a potential enzyme‐based carrier for colon‐specific drug delivery. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The role of a novel p‐phenylen‐bis‐maleamic acid grafted atactic polypropylene interfacial modifier in polypropylene/mica composites as evidenced by tensile properties
Authors: García‐Martínez J. M. , Areso S. , Collar E. P. 
Published: May 2009

AbstractPresent work is devoted to the study of the tensile behavior of polypropylene (PP)/mica composites with improved interfacial interactions from the matrix side caused by the presence of a p‐phenylen‐bis‐maleamic acid grafted atactic polypropylene (aPP‐pPBM) as an interfacial agent. Hence, aPP‐pPBM was previously obtained, in our laboratories, by reactive processing in the melt of a by‐product (atactic PP) from industrial polymerization reactors. Present article is two‐fold, on one hand it has been planned to evidence the so called interfacial effects caused by this novel interfacial agent (aPP‐pPBM) yielding better final properties of the heterogeneous system as a whole as revealed by tensile mechanical properties, and on the other to obtain models to forecast the overall behavior of the system. For such purpose, a Box‐Wilson experimental design considering the amount of mica particles and of interfacial agent as independent variables was used to obtain polynomials to forecast the behavior of the PP/Mica system in the experimental space scanned. The existence of a critical amount of aPP‐pPBM to optimize mechanical properties appears to emerge. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Characterization of highly filled wood flour–PVC composites: Morphological and thermal studies
Authors: Marathe D. S. , Joshi P. S. 
Published: May 2009

AbstractComposites with polyvinyl chloride (PVC) as major matrix constituent, ethylene vinyl acetate (EVA) as polymeric plasticizer and wood flour (WF) and fly ash (FA) as filler were extruded. Morphology of the samples was studied using scanning electron microscopy (SEM). Morphological study indicated good dispersion of the constituents. Infrared spectroscopy (IR) indicates interaction between EVA and PVC and also between the polymeric matrix and WF. The effect of various constituents on glass transition temperature (Tg) was evaluated using differential scanning calorimetry. Addition of EVA decreased the Tg, whereas Tg was increased due to addition of WF and FA. Study indicated that reduction in Tg on addition of EVA was compensated by increase in Tg due to addition of WF. The contribution of FA to change in Tg was not significant. Resulting composites have Tg close to that of PVC. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and characterization of ultra‐low molecular weight poly(vinyl alcohol) graft copolymer
Authors: Guo MinJie , Xia JianJun , Fan Zhi , Zhao Zhuo , Mi HuaiFeng 
Published: May 2009

AbstractGraft reaction of acrylamide (AM) and 4‐vinyl pyridine (4‐VP) onto ultra‐low molecular weight poly(vinyl alcohol) by ceric (IV) ion initiation had been systematically investigated; and the graft conditions were optimized by studying the effect of monomer/initiator concentration, solvents composition, reaction time and temperature. At optimized conditions, the maximum grafting efficiency and grafting ratio was ∼ 50% and 51%, respectively with the presence of AM, whereas they decreased to 19% and 23%, respectively, without the presence of AM. Thermogravimetric analysis showed that as‐resulted graft copolymer had a lower thermal stability than homopolymer PVA. FTIR and 1H‐NMR confirmed chemical structure of as‐synthesized graft copolymer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Shear‐induced crystallization of injection molded vetiver grass‐polypropylene composites
Authors: Somnuk Usa , Suppakarn Nitinat , Sutapun Wimonlak , Ruksakulpiwat Yupaporn 
Published: May 2009

AbstractVetiver grass was used as an alternative filler in polypropylene (PP) composites in this study. Chemical treatment of vetiver grass by alkalization was carried out to obtain alkali‐treated vetiver grass. It was shown that alkali‐treated vetiver grass exhibited higher thermal stability than untreated vetiver grass. Injection molding was used to prepare the composites. The microstructure of injection molded samples showed a distinct skin layer due to shear‐induced crystallization. It was found that normalized thickness of shear‐induced crystallization layer of the composite was lower than that of neat PP. The effect of vetiver particle sizes on shear‐induced crystallization and physical properties of the composites were elucidated. Furthermore, the effect of processing conditions on shear‐induced crystallization, degree of crystallinity, gapwise crystallinity distribution, and mechanical properties of the composite were investigated. It was shown that injection speed and mold temperature affected the normalized thickness of shear‐induced crystallization layer and degree of crystallinity of the composites. However, processing conditions showed insignificant effect on the mechanical properties of vetiver fiber‐PP composites. The degree of crystallinity showed no distribution throughout the thickness direction of the composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Aqueous dispersions of DBSA‐doped polyaniline: One‐pot preparation, characterization, and properties study
Authors: Babazadeh Mirzaagha 
Published: May 2009

AbstractAniline was polymerized in the presence of dodecylbenzene sulfonic acid (DBSA) as a functionalized protonic acid, in an aqueous medium to directly synthesize polyaniline (PANI)‐DBSA particles. DBSA acted as a dopant and a surfactant with stabilizing PANI‐DBSA dispersions by formation of strong hydrogen bonds. The NH+…SO interactions between the PANI chains and the DBSA appeared at 1026 cm−1 in Fourier transform infrared (FTIR) spectrum. Elemental analysis was used to determine the degree of sulfonation (S/N ratio) of PANI chains and resulted that the sulfur‐to‐nitrogen ratio is 0.35. Thermogravimetric analysis (TGA) technique was used to analyze thermal properties of the particles and resulted that the synthesized PANI‐DBSA particles have high thermal stability. The moisture, DBSA and PANI contents of the PANI‐DBSA were estimated from TGA curve, and then the number of aniline repeating units doped with one DBSA molecule was approximately calculated. X‐ray diffraction (XRD) analysis confirmed that a chemical crosslinking reaction occurs between the PANI chains during thermal treatment of PANI‐DBSA. The morphology of PANI‐DBSA powder was investigated by scanning electron microscopy technique and showed that the PANI particles develops from round particles to a smooth surface. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Adhesion of surface‐grafted low‐density polyethylene plates with enzymatically modified chitosan solutions
Authors: Noto Katsuhiko , Matsumoto Saeko , Takahashi Yasuhiro , Hirata Mitsuo , Yamada Kazunori 
Published: May 2009

AbstractAn investigation was undertaken on application of dilute chitosan solutions modified by tyrosinase‐catalyzed reaction with 3,4‐dihydroxyphenetylamine (dopamine) to adhesion of the low‐density polyethylene (LDPE) plates surface‐grafted with hydrophilic monomers. Tensile shear adhesive strength effectively increased with an increase in the grafted amount for methacrylic acid‐grafted and acrylic acid‐grafted LDPE (LDPE‐g‐PMAA and LDPE‐g‐PAA) plates. In particular, substrate breaking was observed at higher grafted amounts for LDPE‐g‐PAA plates. The increase in the amino group concentration of the chitosan solutions and molecular mass of the chitosan samples led to the increase in adhesive strength. Adhesive strength of the PE‐g‐PMAA plates prepared at lower monomer concentrations sharply increased at lower grafted amounts, which indicates that the formation of shorter grafted PMAA chains is an effective procedure to increase adhesive strength at lower grafted amounts. Infrared measurements showed that the reaction of quinone derivatives enzymatically generated from dopamine with carboxyl groups was an important factor to increase adhesive strength in addition to the formation of the grafted layers with a high water absorptivity. The above‐mentioned results suggested that enzymatically modified dilute chitosan solutions can be applied to an adhesive to bond polymer substrates. The emphasis is on the fact that water is used as a solvent for preparation of chitosan solutions and photografting without any organic solvents. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of molecular weight on electroluminescence of nanogold‐bonded poly(9,9‐dioctylfluorene‐alt‐thiophene) at a constant polymer‐to‐gold weight ratio
Authors: Ji Hong‐Da , Tu Yen‐Ching , Wu Sheng‐Han , Liu Cheng‐Hao , Su Yu‐Wei , Tsiang Raymond Chien‐Chao 
Published: May 2009

AbstractThe effects of molecular weight on electroluminescent properties of the light emitting polymeric nanocomposite, poly(9,9‐dioctylfluorene‐alt‐thiophene) with chemically bonded gold nanoparticles (PDOFT‐Au), have been studied under a condition of constant polymer‐to‐gold weight ratio. The polymer, PDOFT, was first synthesized via the Suzuki cross‐coupling reaction and then bonded to in situ‐formed gold nanoparticles (AuNPs) via terminal thiol functional groups which had been generated during the quenching of polymerization. A series of PDOFT‐Au's of various molecular weights have thus been synthesized. At a constant polymer‐to‐gold weight ratio, the average size of gold nanoparticles (AuNPs) increased with an increase in the molecular weight of PDOFT. Although an increased molecular weight led to a red shift in UV‐absorption and PL spectra as well as an increased PL quantum efficiencies (ϕPL) for all samples (both PDOFT and PDOFT‐Au), the effect of AuNPs bonding became more noticeable when the molecular weight was higher. As for light emitting diode (LED) device fabrication, an increase in the molecular weight of PDOFT also led to a red shift in the EL spectra of the fabricated LED devices. Nevertheless, PDOFT‐Au, compared with PDOFT, had a lower threshold voltage, an increased brightness and current density, and an improved photometric efficiency. Moreover, the photometric efficiency increased with an increase in the molecular weight of the polymer, from 0.298 cd/A for PDOFT‐Au3 up to 0.645 cd/A for PDOFT‐Au1. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Biomedical property modifications of poly(vinyl chloride) with methoxylated poly(ethylene glycol)‐poly(ε‐caprolactone) diblock copolymer
Authors: Zhang Tao , Pan Meiyu , Dai Ji , Song Zhexian , He Ling , Jiang Zhengsheng 
Published: May 2009

AbstractManufacturing biomedical flexible Poly (vinyl chloride) (PVC) products requires the nontoxic plasticizers and the biocompatibility. In this study, a series of methoxylated poly(ethylene glycol)‐poly(ε‐caprolactone) diblock copolymer (MPEG‐PCL) with variety molecule weight were synthesized by ring‐opening polymerization of ε‐caprolactone with methoxylated poly(ethylene glycol) (MPEG) as macroinitiator. The structure of the block copolymers was characterized utilizing FTIR, NMR, SEC, and DSC. Because the compatibility between PVC and PCL, a series of MPEG‐PCL/PVC blends were prepared. The results of DSC and mechanical properties of blends show that PVC could be plasticized with MPEG‐PCL and the diblock copolymer is probably to be used as a polymeric plasticizer for PVC. Moreover, the water contact angle results indicated that MPEG‐PCL also provided PVC the hydrophilic properties. At the same time, it was found that the blends showed favorable anticoagulation property which can probably exploit the potential application of the blends in the biomedical areas. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis, characterization, and application of composite alginate microspheres with magnetic and fluorescent functionalities
Authors: Liu Jiwei , Zhang Yu , Yang Ting , Ge Yuqing , Zhang Song , Chen Zhongping , Gu Ning 
Published: May 2009

AbstractComposite alginate microspheres were synthesized via a modified emulsification technique and characterized by inverted optical microscope, transmission electron microscope, ζ‐potential analyzer, UV–vis spectrophotometer, luminescence spectrometer, and vibrating sample magnetometer. The results show that the synthetic parameters including the weight ratio of maghemite nanoparticles to alginate, hydrophile‐lipophile balance (HLB) value, stirring speed, and CaCl2 dripping rate play important roles in the synthesis of microspheres. Furthermore, the composite alginate microspheres exhibit good superparamagnetism and fluorescence, which can serve both as magnetic resonance contrast agents and optical probes for biological imaging. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of ingredients on thermal and mechanical properties of acrylic bone cements
Authors: Endogan Tugba , Serbetci Kemal , Hasirci Nesrin 
Published: May 2009

AbstractThere is a very delicate relation between the amounts of all the ingredients present in the cement composition and the properties of the product. In this study, homogeneous poly(methyl methacrylate) (PMMA) microspheres were prepared by suspension polymerization technique, and used in cement formulations. Various acrylic cements with different compositions were prepared by using PMMA microspheres, methyl methacrylate (MMA) monomer, radiopaque agent of barium sulfate (BaSO4), inorganic particles of hydroxyapatite (HA), initiator and chain stopping agent of 1‐dodecyl mercaptan (DDM). The effects of these additives on mechanical and thermal properties of the resultant cements were examined. Addition of 8% HA relative to the solid parts caused an increase in both tensile and compressive strengths from 20.40 to 25.20 MPa, and from 84.04 to 89.57 MPa, respectively, while curing temperature was decreased about 3 degrees. Chain stopping agent of DDM caused a sharp decrease about 30 degrees in the curing temperature. Radiopaque agent of barium sulfate caused inverse effect on mechanical and thermal properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The totally miscible in ternary hydrogen‐bonded polymer blend of poly(vinyl phenol)/phenoxy/phenolic
Authors: Kuo Shiao‐Wei 
Published: May 2009

AbstractThe individual binary polymer blends of phenolic/phenoxy, phenolic/poly(vinyl phenol) (PVPh), and phenoxy/PVPh have specific interaction through intermolecular hydrogen bonding of hydroxyl–hydroxyl group to form homogeneous miscible phase. In addition, the miscibility and hydrogen bonding behaviors of ternary hydrogen bond blends of phenolic/phenoxy/PVPh were investigated by using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy, and optical microscopy. According to the DSC analysis, every composition of the ternary blend shows single glass transition temperature (Tg), indicating that this ternary hydrogen‐bonded blend is totally miscible. The interassociation equilibrium constant between each binary blend was calculated from the appropriate model compounds. The interassociation equilibrium constant (KA) of each individually binary blend is higher than any self‐association equilibrium constant (KB), resulting in the hydroxyl group tending to form interassociation hydrogen bond. Photographs of optical microscopy show this ternary blend possess lower critical solution temperature (LCST) phase diagram. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Polyurethane networks from different soy‐based polyols by the ring opening of epoxidized soybean oil with methanol, glycol, and 1,2‐propanediol
Authors: Wang Cheng‐Shuang , Yang Li‐Ting , Ni Bao‐Lian , Shi Guang 
Published: May 2009

AbstractA series of polyols with a range of hydroxyl (OH) numbers based on soybean oil and epoxidized soybean oil were prepared by oxirane ring opening with methanol, glycol, and 1,2‐propanediol. The polyols, with average functionalities varying from 2.6 to 4.9, were characterized. Novel cast polyurethane resins were synthesized from these polyols and 2,4‐toluene diisocyanate. The sol fraction of the network decreased as the OH number of the polyol from which it was synthesized increased. None of the samples were completely soluble. The crosslinking density of the polyurethanes correlated directly with the functionality of the polyols. The thermal and mechanical properties of the cast resins were characterized with differential scanning calorimetry and thermogravimetry. The glass‐transition temperature increased with the OH number increasing, and the thermal stability of the resins was slightly decreased with the OH number increasing. The tensile strength at break increased with the OH number increasing. Polyurethanes prepared from polyols with OH numbers higher than 170 mg of KOH/g were glassy, whereas those with OH numbers below that value were rubbery. Glassy polyurethanes displayed decent mechanical strength, whereas rubbery samples showed relatively poor elastic properties and were characterized by lower strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009