bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of (Fe3O4/MWCNTs)/ epoxy nanocomposites
Authors: Jones Wanda D. , Rangari Vijaya K. , Hassan Tarig A. , Jeelani Shaik 
Published: January 2010

AbstractA sonochemical technique is used for in situ coating of iron oxide (Fe3O4) nanoparticles on outer surface of MWCNTs. These Fe3O4/MWCNTs were characterized using a high‐resolution transmission electron microscope (HRTEM), X‐ray diffraction, and thermogravimetric analysis. The as‐prepared Fe3O4/MWCNTs composite nanoparticles were further used as reinforcing fillers in epoxy‐based resin (Epon‐828). The nanocomposites of epoxy were prepared by infusion of (0.5 and 1.0 wt %) pristine MWCNTs and Fe3O4/MWCNTs composite nanoparticles. For comparison purposes, the neat epoxy resin was also prepared in the same procedure as the nanocomposites, only without nanoparticles. The thermal, mechanical, and morphological tests were carried out for neat and nanocomposites. The compression test results show that the highest improvements in compressive modulus (38%) and strength (8%) were observed for 0.5 wt % loading of Fe3O4/MWCNTs. HRTEM results show the uniform dispersion of Fe3O4/MWCNTs nanoparticles in epoxy when compared with the dispersion of MWCNTs. These Fe3O4/MWCNTs nanoparticles‐infused epoxy nanocomposite shows an increase in glass transition (Tg) temperature. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
New melamine–formaldehyde–ketone resins. VI. Preparation of filled molding compositions and compression‐molding materials from reactive solvents based on cyclohexanone
Authors: Głowacz‐Czerwonka Dorota , Kucharski Mieczysław 
Published: January 2010

AbstractThe conditions and a method of preparing new molding compositions and filled compression‐molding materials from melamine–formaldehyde–cyclohexanone resins are described. The resins were obtained from melamine solutions in a reactive solvent prepared by the reaction of 1 mol of cyclohexanone with 7 mol of formaldehyde. The fillers were wood powder and sulfite cellulose. The thermal properties of the samples prepared from the compositions were studied with dynamic thermal analysis, thermogravimetry, and differential scanning calorimetry analysis. Selected mechanical properties [Brinell hardness, unnotched impact strength (Charpy method), and bending strength] of the cured resins were also measured. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of natural polyphenols on physicochemical properties of crosslinked gelatin‐based polymeric biocomposite
Authors: Haroun A. A. , El Toumy S. A. 
Published: January 2010

AbstractThis work was aimed to study the effect of natural polyphenols extract (Acacia nilotica bark) on physicochemical properties of crosslinked gelatin‐poly(acrylamide‐co‐acrylic acid), Gel‐poly(AAm‐co‐Ac), polymeric biocomposite film. Gelatin‐based composite films have extensive application as biocompatible biomaterial as drug carriers, cosmetics, and agricultural food packaging. The prepared composite films were characterized using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC), in addition to the swelling and degradation behavior. UV‐Vis absorption spectra and scanning electron microscopy (SEM) were also applied to observe the interaction between Gel‐poly(AAm‐co‐Ac) and natural polyphenol (catechin). The study has demonstrated that the involvement of hydrogen bonding and hydrophobic interactions as the major forces involved in the stabilization of gelatin‐based polymeric biocomposite film by the plant polyphenols (catechin and gallic acid derivatives). Thermal stability studies of crosslinked gelatin‐based composite film revealed that A. nilotica bark extract stabilizes the gelatin molecules and leads to moderate increase of the denaturation temperatures relative to the uncrosslinked one. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Studies on polymeric conservation treatments of ceramic tiles with Paraloid B‐72 and two alkoxysilanes
Authors: Constâncio Célia , Franco Liliana , Russo Ariana , Anjinho Carlos , Pires João , Vaz M. Fátima , Carvalho Ana P. 
Published: January 2010

AbstractThe aim of this study was to evaluate the effect of different polymeric protections applied on ceramic tiles on their mechanical and water absorption properties. Three conservation products were used: the acrylic polymer Paraloid B‐72 and two alkoxysilane‐based formulations (tetraethoxysilane (TEOS) and IN2210, a polidimetilsiloxane‐based formulation). The coatings were applied onto handmade tiles manufactured according to a 18th century procedure. Different application procedures (immersion, brushing, and spraying) were tested. The protection effectiveness was assessed through capillary water absorption and four point bending tests. The mineralogical characterization of tiles was undertaken by XRD. The best protective properties of the tiles were achieved by immersion treatments with Paraloid B‐72 based on the protocols followed by the museums restoration departments. Nevertheless, the results of the present work show that the second immersion in Paraloid B‐72 solution, commonly made, can be eliminated, as it does not provide any significant increase in the hydrophobic or mechanical properties of the tiles. As a result, there are obvious economical benefits, as the coating process became less time‐consuming and more environmental friendly, as the amount of organic compounds is reduced. On the other hand, the use of small volumes of Paraloid B‐72 solution applied by brush, or IN2210 sprayed can provide good results, if the only purpose of the treatment is the increase of the hydrophobic properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Microwave assisted polycondensation of polyimides by [4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, pyromellitic dianhydride] and [2,4,6‐trimethyl‐m‐phenylenediamine]. Power, time, and solvent effect
Authors: Tellez Hugo Mendoza , Alquisira Joaquín Palacios , López‐Cortés José Guadalupe , Alvarez‐Toledano Cecilio 
Published: January 2010

AbstractThe microwave assisted polycondensation of two polyimides were studied using pyromellitic dianhydride (PMDA), and 4,4′‐(hexafluoroisopropyliden)diphthalic anhydride (6FDA) as dianhydride monomers and 2,4,6‐trimethyl‐m‐phenylenediamine (TrmPD), as diamine monomer, under microwave irradiation in DMF and DMSO solvents. The structure and performance of polymers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), viscosity, density, and Thermogravimetric Analysis (TGA). The results show that the polyimides can be obtained in a short reaction time with high intrinsic viscosity and high yield. The effect of the presence of a bridging group, C(CF3)2, in the monomer structure is apparent in the permeability parameters of the macromolecules as polymer (6FDA‐TrmPD) always presents better results than polymer (PMDA‐TrmPD). Properties as density and Tg increases with the time exposition to the microwave irradiation. Polyimides obtained present good thermal properties because they began to lose weight in a range of 8–16% at high temperature as 450°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Melamine‐bridged alkyl resorcinol modified urea–formaldehyde resin for bonding hardwood plywood
Authors: Hse Chung‐Yun , Higuchi Mitsuo 
Published: January 2010

AbstractA powdery product was obtained by the reaction of methylolated melamine with alkyl resorcinols to form melamine‐bridged alkyl resorcinols (MARs). The effects of the addition of this powder on the bonding strength and formaldehyde emission of urea–formaldehyde (UF) resins were investigated. Three types of UF resins with a formaldehyde/urea molar ratio of 1.3 synthesized by condensation at pH 1.0 (UF‐1.0), pH 4.5 (UF‐4.5), and pH 5.0 (UF‐5.0) were fabricated. The addition of MAR to UF‐4.5 and UF‐5.0 for bonding hardwood plywood enhanced the bonding strength and reduced formaldehyde emission. For UF‐1.0, the addition of MAR adversely affected the bonding strength. However, the UF‐1.0 resin yielded the lowest formaldehyde emission of all of the UF resins in the study. The effects of the MAR addition were related to the molecular structures of the UF resins. UF‐1.0 contained a large amount of free urea, a considerable number of urons, and a highly methylene‐linked, ring‐structured higher molecular weight fraction and had a smaller number of methylol groups. Therefore, the addition of MAR was considered to cause a shortage of the methylol groups, which in turn, led to incomplete resin curing. In contrast to UF‐1.0, UF‐5.0 contained a smaller amount of free urea and a linearly structured higher molecular weight fraction and had a larger number of methylol groups. In this case, MAR was considered to effectively react with the methylol groups to develop a three‐dimensional crosslinked polymer network to enhance the bonding strength and suppress the generation of free formaldehyde to reduce formaldehyde emission. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Design and performance evaluation of multilayer packaging films for blister packaging applications
Authors: Hwang S. W. , Shim J. K. , Lee S. B. , Auras R. 
Published: January 2010

AbstractFive multilayer packaging film structures consisting of amorphous poly(ethylene terephthalate) (APET), low‐density polyethylene (LDPE), polypropylene (PP), and acrylonitrile/methyl acrylate copolymer (Barex) films [i.e., APET/polyethylene (PE), APET/PP, APET/PE + UV inhibitor, APET/PP/PE, and APET/Barex/PP] for blister packaging applications were designed and produced. Blister containers with APET/PE and APET/Barex/PP structures were prepared, and their optical, mechanical, barrier (O2, CO2, and H2O), physical, and product/package compatibility performance properties were evaluated. Package/product compatibility with simulants (soy sauce and sunscreen skin cream) at 37.8°C was evaluated for 3, 7, 14, and 28 days in the multilayer films and the blister containers. APET/Barex/PP film showed significantly better O2 and CO2 barrier performance than the other four film structures. The UV inhibitor had no significant effect on the barrier properties in the APET/PE film structure. All of the film structures showed high enough elastic storage modulus values to be applied to blister packaging in a broad range of temperatures between −45 and 80°C. The glass‐transition temperature of APET, which was responsible for the elastic modulus of the multilayer structure, decreased after the samples were exposed to the skin cream. This decrease may have been due to the sorption of the skin cream's active ingredients, such as ethylhexyl methoxycinnamate. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and application of modified starch as a shell–core main adhesive in a foundry
Authors: Zhou Xia , Yang Jinzong , Qian Feng , Qu Guohui 
Published: January 2010

AbstractTo be used as an alternative adhesive for sand cores in a foundry, a solid water‐soluble modified starch [carboxymethyl starch (CMS)] was synthesized by a new dry reaction process. With this process, a series of CMS products was obtained with degrees of substitution (DSs) ranging from 0.25 to 0.78 at a high reaction efficiency and characterized with regard to their molecular structure and aqueous solution viscosity. On the basis of the dry synthesis of CMS, the properties of CMS‐bonded shell–core sand were investigated, and practical production experiments were carried out. The results show that there was a new sharp peak in the infrared spectrum that represented the carboxymethyl groups and formation of CMS. The viscosity of the CMS aqueous solution increased with increasing DS and amount of CMS. When DS was in the range 0.3–0.5 and the mass fraction was 5–7%, the CMS aqueous solution had a suitable viscosity, which was helpful for the improvement of the properties, such as flowability, permeability, and strength, of the CMS core sand. In addition, a CMS shell–core with an appropriate wall thickness (10–20 mm) for the purpose of obtaining both sufficient strength and permeability could be made with the CMS‐bonded core sand and a hot‐core‐box process. The final pouring results prove that high‐quality iron castings with smooth inner cavities could be produced with the CMS‐bonded shell–core and that it (namely the CMS‐bonded shell‐core) could be used as a replacement for the furan resin‐bonded sand core. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of starch and glycerol on the properties of chitosan by positron annihilation spectroscopy
Authors: Abd El Wahab M. , Abdou E. S. 
Published: January 2010

AbstractTwo types of chitosan (CS), α and β, were blended with different concentrations of starch and cast to obtain films. The addition of 1% glycerol was used as a plasticizer to increase film flexibility. The properties of the obtained films were studied by positron annihilation lifetime spectroscopy, X‐ray diffraction, and scanning electron microscopy. The results indicate that pure β‐CS had smaller size free‐volume holes with high fractions than pure α‐CS; this was attributed to the difference in bonding of main chains in β‐CS. The addition of starch (>20% up to 50%) reduced the size of the free‐volume holes and increased their fraction because of the close packing of chain segments. The effect of 1% glycerol to the CS starch blends indicated that some modification took place. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effects of membrane thickness and heat treatment on the gas transport properties of membranes based on P84 polyimide
Authors: Shen Yi , Lua Aik Chong 
Published: January 2010

AbstractP84 polyimide membranes with thicknesses ranging from 6 to 310 μm were successfully fabricated by spin coating. The glass transition temperature of the P84 powder was found to be 315°C using differential scanning calorimetry, whereas its decomposition temperature was 536°C using thermogravimetric analysis. Scanning electron microscopy was used to examine the morphology of the membranes. The permeability of single gas (He, N2, O2, and CO2) and the ideal selectivity of gas pair (O2/N2, He/CO2, CO2/N2, and He/O2), as a function of membrane thickness, were determined. The results showed that the permeability of a single gas increased with increasing membrane thickness, whereas the selectivity of a given gas pair was nearly independent of the membrane thickness. The average selectivity of O2/N2, He/CO2, CO2/N2, and He/O2 were found to be 8.2, 10.0, 12.9, and 15.8, respectively. The effects of heat treatment on the membrane morphology and gas transport properties were investigated for three annealing temperatures, i.e., 80°C, 200°C, and 315°C. The membrane annealed at 315°C was cracked due to the stress sustained either during heating or cooling, thereby resulting in little or no selectivity. The permeabilities of P84‐118 membrane (118 μm thickness) annealed at 80°C were 16.2, 0.196, 1.20, and 2.01 Barrer for He, N2, O2, and CO2, respectively. The permeabilities of P84‐118 membrane annealed at 200°C decreased by 9.75%, 47.96%, 25.83%, and 30.85% for He, N2, O2, and CO2, respectively, as compared with those at 80°C, whereas the ideal selectivities increased by 42.65%, 30.52%, 32.85%, and 21.63% for O2/N2, He/CO2, CO2/N2, and He/O2, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Unique stimuli responsive characteristics of electron beam synthesized bacterial cellulose/acrylic acid composite
Authors: Halib Nadia , Amin Mohd Cairul Iqbal Mohd , Ahmad Ishak 
Published: January 2010

AbstractThe formation and swelling behavior of bacterial cellulose/acrylic acid hydrogel prepared from aqueous mixture consists of 20 : 80 (v/v) acrylic acid (AAc) and 1% bacterial cellulose dispersion under accelerated electron beam was investigated. Gel fraction of hydrogel increased with the increasing dose suggesting a denser composite at 50 kGy compared to 35 kGy. SEM photomicrographs revealed a homogenous pores distribution at higher dose with pore sizes ranging from 1 to 5 μm. Hydrogel synthesized at lower dose of electron beam exhibited higher swelling ability and the degree of swelling increased as the pH of surrounding medium increased and it reached the optimum swelling at pH 7. While swelling of the hydrogel decreased with the increasing ionic strength of solution, swelling at different temperatures ranging from 25 to 50°C revealed a unique character where the hydrogel shrunk at 37°C. Moreover, hydrogel synthesized at higher dose exhibited a higher degree of swelling in methanol with respect to water. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Competitive adsorption between an AMPS®‐based fluid loss polymer and Welan gum biopolymer in oil well cement
Authors: Plank Johann , Lummer Nils Recalde , Dugonjić‐Bilić Fatima 
Published: January 2010

AbstractWater‐soluble 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS®)‐based copolymers are commonly used to provide water retention (fluid loss control) for oil well cement slurries. Here, the fluid loss performance of a CaAMPS®‐N,N‐dimethylacrylamide copolymer (CaAMPS®‐co‐NNDMA) in the presence of Welan gum, an anionic microbial biopolymer produced by anaerobic fermentation using Alcaligenes ATCC 31555 bacteria was investigated at 80°C. Welan gum is used to control unwanted free water development at the surface of the cement slurry. The effectiveness of CaAMPS®‐co‐NNDMA fluid loss additive (FLA) solely relies on its high adsorption onto the positively charged surfaces of cement hydrates. Adsorption of the FLA is, however, perturbed by Welan gum. This anionic polysaccharide competes with CaAMPS®‐co‐NNDMA for adsorption sites on the cement surface. This effect is surprising because in cement pore solution, Welan gum exhibits a much lower specific anionic charge amount than CaAMPS®‐co‐NNDMA. The reason is that Welan gum possesses carboxylate functionalities, which are much stronger anchor groups than the sulfonate groups present in CaAMPS®‐co‐NNDMA. The superiority of the carboxylate groups regarding their affinity to the mineral surface, which possesses insufficiently coordinated Ca atoms is confirmed by a higher calcium binding capability for Welan gum than for the FLA. Thus, Welan gum can reduce effectiveness of CaAMPS®‐co‐NNDMA as fluid loss agent by preventing its adsorption or through displacement of already adsorbed FLA molecules from the surface of cement. In multiadmixture systems, which are commonly used in oil well cement, concrete or mortars, competitive adsorption between different additives for surface sites can negatively impact the performance of these additives. Understanding the reasons behind can help to develop more effective admixture systems. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Genetic variation at the IRF7/PHRF1 locus is associated with autoantibody profile and serum interferon‐α activity in lupus patients
Authors: Salloum Rafah , Franek Beverly S. , Kariuki Silvia N. , Rhee Lesley , Mikolaitis Rachel A. , Jolly Meenakshi , Utset Tammy O. , Niewold Timothy B. 
Published: January 2010

AbstractObjectiveInterferon‐α (IFNα) is a heritable risk factor for systemic lupus erythematosus (SLE). Genetic variation near IRF7 is implicated in SLE susceptibility. SLE‐associated autoantibodies can stimulate IFNα production through the Toll‐like receptor/IRF7 pathway. This study was undertaken to determine whether variants of IRF7 act as risk factors for SLE by increasing IFNα production and whether autoantibodies are important to this phenomenon.MethodsWe studied 492 patients with SLE (236 African American, 162 European American, and 94 Hispanic American subjects). Serum levels of IFNα were measured using a reporter cell assay, and single‐nucleotide polymorphisms (SNPs) in the IRF7/PHRF1 locus were genotyped.ResultsIn a joint analysis of European American and Hispanic American subjects, the rs702966 C allele was associated with the presence of anti–double‐stranded DNA (anti‐dsDNA) antibodies (odds ratio [OR] 1.83, P = 0.0069). The rs702966 CC genotype was only associated with higher serum levels of IFNα in European American and Hispanic American patients with anti‐dsDNA antibodies (joint analysis P = 4.1 × 10−5 in anti‐dsDNA–positive patients and P = 0.99 in anti‐dsDNA–negative patients). In African American subjects, anti‐Sm antibodies were associated with the rs4963128 SNP near IRF7 (OR 1.95, P = 0.0017). The rs4963128 CT and TT genotypes were associated with higher serum levels of IFNα only in African American patients with anti‐Sm antibodies (P = 0.0012). In African American patients lacking anti‐Sm antibodies, an effect of anti‐dsDNA–rs702966 C allele interaction on serum levels of IFNα was observed, similar to the other patient groups (overall joint analysis P = 1.0 × 10−6). In European American and Hispanic American patients, the IRF5 SLE risk haplotype showed an additive effect with the rs702966 C allele on IFNα level in anti‐dsDNA–positive patients.ConclusionOur findings indicate that IRF7/PHRF1 variants in combination with SLE‐associated autoantibodies result in higher serum levels of IFNα, providing a biologic relevance for this locus at the protein level in human SLE in vivo.
Bim–Bcl‐2 homology 3 mimetic therapy is effective at suppressing inflammatory arthritis through the activation of myeloid cell apoptosis
Authors: Scatizzi John C. , Hutcheson Jack , Pope Richard M. , Firestein Gary S. , Koch Alisa E. , Mavers Melissa , Smason Avraham , Agrawal Hemant , Haines G. Kenneth , Chandel Navdeep S. , Hotchkiss Richard S. , Perlman Harris 
Published: January 2010

AbstractObjectiveRheumatoid arthritis (RA) is a destructive autoimmune disease characterized by an increased inflammation in the joint. Therapies that activate the apoptotic cascade may have potential for use in RA; however, few therapeutic agents fit this category. The purpose of this study was to examine the potential of Bim, an agent that mimics the action of Bcl‐2 homology 3 (BH3) domain–only proteins that have shown success in preclinical studies of cancer, in the treatment of autoimmune disease.MethodsSynovial tissues from RA and osteoarthritis patients were analyzed for the expression of Bim and CD68 using immunohistochemistry. Macrophages from Bim−/− mice were examined for their response to lipopolysaccharide (LPS) using flow cytometry, real‐time polymerase chain reaction analysis, enzyme‐linked immunosorbent assay, and immunoblotting. Bim−/− mice were stimulated with thioglycollate or LPS and examined for macrophage activation and cytokine production. Experimental arthritis was induced using the K/BxN serum–transfer model. A mimetic peptide corresponding to the BH3 domain of Bim (TAT‐BH3) was administered as a prophylactic agent and as a therapeutic agent. Edema of the ankles and histopathologic analysis of ankle tissue sections were used to determine the severity of arthritis, its cellular composition, and the degree of apoptosis.ResultsThe expression of Bim was reduced in RA synovial tissue as compared with controls, particularly in macrophages. Bim−/− macrophages displayed elevated expression of markers of inflammation and secreted more interleukin‐1β following stimulation with LPS or thioglycollate. TAT‐BH3 ameliorated arthritis development, reduced the number of myeloid cells in the joint, and enhanced apoptosis without inducing cytotoxicity.ConclusionThese data demonstrate that BH3 mimetic therapy may have significant potential for the treatment of RA.