bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal and mechanical properties of silicon rubber/cis‐polybutadiene rubber/ethylene–propylene–diene monomer blends
Authors: Wu Weili , Chen Dajun 
Published: June 2006

AbstractConsidering the properties of silicon rubber, ethylene–propylene–diene monomer (EPDM), and cis‐polybutadiene rubber (BR), a blend made by a new method was proposed in this article; this blend had thermal resistance and good mechanical properties. The morphology of the blend was studied by SEM, and it was found that the adhesion between the phases of BR, EPDM, and polysiloxanes (silicon rubber) could be enhanced, and the compatibility and covulcanization were good. The influence of the mass ratio of peroxide and silica on the mechanical properties and thermal resistance of the blend was studied. The results showed that the mechanical properties and thermal resistance of the blend were improved when silicon rubber/BR/EPDM was 20/30/50, dicumyl peroxide/sulfur was 2.5/2.5, and the amount of silica was 80 phr. The integral properties of rubber blend had more advantages than did the three rubbers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4462–4467, 2006
Flame retardancy of polycarbonate–polydimethylsiloxane block copolymer/silica nanocomposites
Authors: Nodera Akio , Kanai Toshitaka 
Published: June 2006

AbstractThis report describes the flame retardancy and the thermal degradation behavior of polycarbonate–polydimethylsiloxane (PC–PDMS) block copolymer/silica nanocomposites. PC–PDMS block copolymer with dimethylsiloxane (DMS) block size 40 units increased the dispersibility of nanosized amorphous silica. Addition of the slight nanosized silica caused the increment of flame retardancy of PC–PDMS block copolymer, and the PC–PDMS block copolymer with 1.0 wt % PDMS had the highest limiting oxygen index value when the nanosized silica was added 0.5 wt %. The maximum rate temperature of the PC–PDMS block copolymer increased with the addition of silica and the maximum loss rate was the lowest when silica content is 0.5 wt %. The monodisperse nanosized silica had an effect that enhances the flame retardant mechanism of PDMS for PC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3862–3868, 2006
Behavior of immobilized glucose oxidase on membranes from polyacrylonitrile and copolymer of methylmethacrylate‐dichlorophenylmaleimide
Authors: Vasileva N. , Godjevargova Tz. , Konsulov V. , Simeonova A. , Turmanova S. 
Published: June 2006

AbstractTwo new ultrafiltration membranes were obtained from a polymer mixture, containing 60% polyacrylonitrile (PAN) and 40% copolymer of methylmethacrylate‐dichlorophenylmaleimide (MMA‐DCPMI). Membrane 1 (MB1) contains 40% DCPMI of the copolymer, and membrane 2 (MB2) contains 15% of the copolymer. The pore size, the specific surface, the water content, the water flux, and the selectivity were determined for the two membranes. The presence of dichlorophenylmaleimide in the copolymer ensures the preparation of membranes suitable for direct covalent enzyme immobilization without further modifications. These membranes were used for immobilization of glucose oxidase (GOD). High amount of bound protein was found on each of the membranes. High relative activities of the immobilized GOD were achieved, 72% for MB1 and 68% for MB2. The properties of the immobilized enzyme (GOD) were determined: optimum pH and temperature and pH, thermal, and storage stability, and then compared with the properties of the native enzyme. The kinetic parameters of the enzyme reaction, Michaelis constant (Km) and maximum reaction rate (Vmax), were also investigated. The results obtained showed that the ultrafiltration membranes prepared from the mixture of PAN and the copolymer MMA‐DCPMI were suitable for use as carriers for the immobilization of GOD. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4334–4340, 2006
High PVC film‐forming composite latex particles via miniemulsification, part 2: Efficiency of encapsulation
Authors: Al‐Ghamdi Ghurmallah H. , Sudol E. David , Dimonie Victoria L. , El‐Aasser Mohamed S. 
Published: June 2006

AbstractThe application of a density gradient column (DGC) method using sodium polytungstate (SPT) solutions as the medium was investigated for determining the encapsulation efficiency of 11–30% pigment volume concentration (PVC)) latex particles prepared by the miniemulsification process. The encapsulation efficiencies for 11, 20, and 30% PVCs were found to be 100% of the TiO2 encapsulated inside 86.3, 98, and 98.9% of the styrene/n‐butyl acrylate copolymer, respectively. The copolymer not participating in the encapsulation (free copolymer) was found in the 1.04 g/mL density layer of the DGC. Particle size analysis by DLS (dynamic light scattering) showed that the encapsulated particle size increased with increasing density. Thus, the number of TiO2 particles (primary particles) inside each encapsulated particle increased to accommodate both the increased size and density. The results obtained by DLS for each DGC layer of the 30% PVC system were confirmed qualitatively by TEM in terms of the increasing encapsulated particle size and broadening of the size distribution as the density increased in the DGC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4517–4525, 2006
High PVC film‐forming composite latex particles via miniemulsification, part 3: Optical properties
Authors: Al‐Ghamdi Ghurmallah H. , David Sudol E. , Dimonie Victoria L. , El‐Aasser Mohamed S. 
Published: June 2006

AbstractThe optical properties of films cast from latexes comprising TiO2 particles encapsulated in poly(styrene‐co‐n‐butyl acrylate) prepared by miniemulsification and having high loading (11–70% pigment volume concentration (PVC)) were investigated. Contrast ratio (CR) measurements for all batches showed that a 3 mil film (obtained at 43% PVC) was the minimum thickness at which 98% CR could be achieved. Also, the greatest hiding power (HP) (535 ft2/gal) was obtained at 43% PVC. In addition, gloss measurements showed that as the TiO2 loading increased, the gloss decreased, indicating that the increasing amount of TiO2 contributed to a reduction in the surface smoothness. The effects of surfactant concentration (sodium lauryl sulfate) on the encapsulated particle size and the optical properties of the encapsulated films for the 11% PVC system are described. The effect of varying the sonifier operating conditions on the TiO2 particle size, encapsulated particle size, and the optical properties of the encapsulated films for the 43% PVC system was also investigated. A comparative study of the optical properties of films cast from encapsulated latex particles with films cast from physical blends of polymer particles and pigment at the same TiO2 loading and film thickness was made. The optical properties (i.e., CR and gloss) showed a clear advantage of the miniemulsification process over the blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4526–4537, 2006
Synthesis, characterization, and film morphology of dodecylpolysiloxane
Authors: An Qiufeng , Cheng Guangwen , Li Linsheng 
Published: June 2006

AbstractA novel polysiloxane softener bearing dodecyl side groups (dodecylpolysiloxane [DDPS]) was synthesized by copolymerization of octamethylcyclotetrasiloxane with dodecyltrimethoxysilane and hexamethyldisiloxane. Chemical structure and film morphology of the synthesized polysiloxane are characterized and investigated by infrared spectrum, 1H‐NMR, field emission scanning electronic microscope, and atomic force microscope. The experiment results indicate that DDPS can form a hydrophobic film on both the cotton fiber and silicon wafer surface. At an amplification of <80,000 (of the original fiber) and the observation rule (working distance) of >200 nm, DDPS shows a relative smooth resin film on the treated fabric/fiber surface. But as the observation rule decreases to 2 nm—almost to a molecular scale—the DDPS film mostly exhibits an inhomogeneous structure and uneven morphology in its atomic force microscope images. There are many low or high peaks that appeared in DDPS topography. Consequently in 2 μm2 scanning field, the root mean square roughness of DDPS film reaches to 0.199 nm, which is 2.46 times rougher as compared with that of polydimethylsiloxane film. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4480–4486, 2006
Supercritical fluid extraction of cyclic oligomers from depolymerizing PBT
Authors: Weijers C. , de Rooij R. D. , Agarwal U. S. , de Wit G. , Lemstra P. J. 
Published: June 2006

AbstractCyclic oligomers of polyester show great potential for a reaction‐injection‐molding process, because of their initial low viscosity and rapid ring‐opening polymerization at low temperatures (180°C) without exothermic reaction or condensates. In this work, we report the synthesis of cyclic oligo(butylene terephthalate) (COBT) from linear poly(butylene terephthalate) by a formation–extraction process employing supercritical fluids (SCF) CO2 and pentane at T = 230°C and P = 250 bar. Following this, depressurization of SCF leads to easy recovery of the COBTs. When compared with SCF CO2, SCF pentane is found to be an attractive solvent because of its higher solubilizing capacity (0.8 mg COBT dimer/g pentane) for the COBTs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4487–4492, 2006
Synthesis and cure of liquid crystalline diallyl modifiers for bismaleimide resin
Authors: Yu Yingfeng , Wang Minghai , Liu Xiaoyun , Zhao Lin , Tang Xiaolin , Li Shanjun 
Published: June 2006

AbstractThree kinds of liquid crystalline aromatic azomethine modifiers were synthesized with high yield, and the modification of bismaleimide resin (BMI) with them was studied by scanning electron microscope, polarizing optical microscope, thermogravimetric analyzer, differential scanning calorimetry, and rheolometry. Blends cured at the temperature of liquid crystalline phase were found to have oriented liquid crystal‐rich phase and improved mechanical properties. The addition of o,o′‐diallyl bisphenol A in the blends of BMI decreases thermal properties but shows little effect on phase structures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4366–4371, 2006
Preparation of core–shell structured alumina–polyaniline particles and their application for corrosion protection
Authors: Zhang Donghua 
Published: June 2006

AbstractPolyaniline (PANI) was synthesized by chemical oxidative polymerization of aniline (ANI) in the presence of alumina (Al2O3) particles. The polymerization of ANI occurred preferentially on the surfaces of the particles, resulting core–shell structured alumina–polyaniline (Al2O3‐PANI) particles. Morphology examination showed that with decreasing of the weight ratio of Al2O3/ANI in the reactants, the thickness of the PANI layer increased and changed from an even surface morphology to a particulate morphology. UV–vis and Fourier transformed infrared (FTIR) spectra indicated that there is no chemical interaction between the PANI layer and the Al2O3 surfaces. The PANI layer adhered well to the particles and can be used as anticorrosive fillers for polymer coatings. Enhanced corrosion protection performance was achieved for the emeraldine base (EB) form of PANI deposited Al2O3 particles (Al2O3‐EB) filled epoxy coating on carbon steel in 3.0 wt % aqueous NaCl solution. The particles demonstrate both excellent corrosion protection performance and lower cost, which will be of great importance in practical applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4372–4377, 2006
Structure–property relationships in one‐component polyurethane adhesives for wood: Sensitivity to low moisture content
Authors: Beaud F. , Niemz P. , Pizzi A. 
Published: June 2006

AbstractThe causes of strength loss of wood joints and their consequent delamination from one‐component polyurethane adhesives used for bonding structural wood when used at a low moisture content was investigated by testing wood joint strength and elongation at rupture at different wood moisture contents and by 13C‐NMR spectroscopy and scanning electron microscopy of the hardened bond line. The combination of the relative proportion of the still‐reactive free NCO groups on the polyurethane, of the wise choice of degree of polymerization of the resin, and of a slower rate of reaction were the three parameters found to be important in overcoming the problem of poor or no bonding of wood at low to very low moisture contents from one‐component polyurethane adhesives. The results obtained indicated that one‐component polyurethane adhesives that had a combination of a higher proportion of still‐unreacted NCO groups, a lower degree of polymerization, and a slower reaction rate were capable of overcoming the problem of the high sensitivity of polyurethane gluing at low to very low wood moisture contents. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4181–4192, 2006
Storage and loss moduli behavior of plasticized epoxy polymers over a frequency and temperature range, and damaging effects assessment by means of the NDT method of ultrasounds and moisture absorption
Authors: Sideridis E. , Prassianakis I. N. , Kytopoulos V. N. 
Published: June 2006

AbstractThe first objective of the present experimental work is to evaluate the storage and loss moduli of plasticized epoxy polymers over a temperature and frequency range, and to correlate with the ability of the ultrasounds for the characterization of such polymers. The materials used were a series of cold‐setting epoxy polymers, plasticized with different amounts of plasticizer. After the investigation of dynamic properties through vibration tests, the velocities of longitudinal and transverse elastic waves, and the acoustic attenuation coefficientawere evaluated and, then, using these quantities, the “dynamic” moduliE′,G′, and ν′ were evaluated. Thereafter, it can be stated that the plasticizer content and measuring frequency range strongly influence the elastic moduli of the material in the sense that the plasticizer tends to reduce, whereas the measuring frequency to increase these. The second objective of this work is to asses and discuss the associated plasticizer‐induced microstructural damaging effects by combined methods of ultrasounds, tensile modulus, as well as moisture absorption testing and then to correlate this assessment with the storage moduli behavior. It was shown that, despite the nonneglecting scatter in the experimental data, certain irresistible general trends might be assessed. In this context, it was found that the damage “response” is markedly sensitive to the respective applied “detection” technique and, therefore, the damage evolution data obtained by these different techniques are comparable only under certain circumstances. By comparison between the applied techniques, it seems reasonable to assume that the “moisture” technique due to its inherent microscopic mass transport processes, in the form of H2O molecules diffusion and therefore its ability to “detect” microstructural detects on a much lower scale, should give a better approach to the internal damage phenomena. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3869–3880, 2006
Curing of DGEBA epoxy resin by low generation amino‐group‐terminated dendrimers
Authors: Xu Dong‐Mei , Zhang Ke‐Da , Zhu Xiu‐Lin 
Published: June 2006

AbstractLow generation amino‐group‐terminated poly(ester‐amine) dendrimers PEA1.0 (NH2)3 and PEA1.5 (NH2)8, and poly(amido‐amine) dendrimer PAMAM1.0 (NH2)4 were used as diglycidyl ether of bisphenol A (DGEBA) epoxy resin hardeners. Thermal behavior and curing kinetics of dendrimer/DGEBA systems were investigated by means of differential scanning calorimetry (DSC). Compared with ethylene diamine (EDA)/DGEBA system, the dendrimer/DGEBA systems gradually liberated heat in two stages during the curing process, and the total heat liberated was less. Apparent activation energy and curing reaction rate constants for dendrimer and EDA/DGEBA systems were estimated. Thermal stabilities and mechanical properties of cured thermosetting systems were examined as well. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3902–3906, 2006
Antigenic targets and pathogenicity of anti–aortic endothelial cell antibodies in Takayasu arteritis
Authors: Chauhan Sunil Kumar , Tripathy Naresh Kumar , Nityanand Soniya 
Published: June 2006

AbstractObjectiveAnti–endothelial cell antibodies are considered to have an important role in the pathogenesis of Takayasu arteritis (TA). Previously, these antibodies were detected using human umbilical vein endothelial cells, which do not completely represent the antigenicity/functions of aortic endothelial cells, the specific targets in TA. To delineate the precise role of antigenic targets, we investigated such targets as well as the pathogenic mechanism of antibodies directed against aortic endothelial cells (AAECAs) in TA.MethodsAAECAs were detected using a cellular enzyme‐linked immunosorbent assay (ELISA), and their antigenic targets were detected by immunoblotting. AAECA‐mediated induction of endothelial adhesion molecule expression and cytokine production was studied by ELISA, and apoptosis was studied using the TUNEL method.ResultsAAECAs were detected in 86% of patients with TA and in 9% of controls. Sera obtained from AAECA‐positive patients with TA recognized a total of 9 antigens ranging in size from 18 kd to 200 kd, of which the 60–65‐kd triplet was recognized most often. The aortic endothelial cell reactivity of Hsp60‐absorbed sera was reduced by ∼50% as compared with that of unabsorbed sera (mean ± SD 0.488 ± 0.08 versus 0.838 ± 0.116). Sera from AAECA‐positive patients with TA, compared with sera from AAECA‐negative patients with TA and that from controls, induced increased expression of E‐selectin (mean ± SD 0.833 ± 0.063 versus 0.217 ± 0.081 and 0.221 ± 0.101 optical density [OD] units, respectively) and vascular cell adhesion molecule 1 (0.620 ± 0.144 versus 0.165 ± 0.005 and 0.177 ± 0.055 OD units, respectively) and increased production of interleukin‐4 (IL‐4) (6.8 ± 2.4 versus 1.2 ± 1.6 and 1.3 ± 2.5 pg/ml, respectively), IL‐6 (24.3 ± 2.4 versus 4.5 ± 6.7 and 5.9 ± 5.1 pg/ml, respectively), and IL‐8 (36.8 ± 10.3 versus 10.1 ± 6.7 and 7.8 ± 2.1 pg/ml, respectively). Sera from AAECA‐positive patients with TA induced 29 ± 6% (median ± SEM) apoptosis of aortic endothelial cells.ConclusionOur data show that the AAECAs that are present in patients with TA are directed mainly against 60–65‐kd antigen(s) and may cause vascular dysfunction by inducing expression of endothelial adhesion molecules, cytokine production, and apoptosis.
Hemorheologic profile in systemic sclerosis: Role of NOS3 −786T>C and 894G>T polymorphisms in modulating both the hemorheologic parameters and the susceptibility to the disease
Authors: Fatini Cinzia , Mannini Lucia , Sticchi Elena , Rogai Veronica , Guiducci Serena , Conforti Maria Letizia , Cinelli Marina , Pignone Alberto Moggi , Bolli Paola , Abbate Rosanna , Cerinic Marco Matucci 
Published: June 2006

AbstractObjectiveMicrovascular disorders are relevant in systemic sclerosis (SSc). Hyperviscosity, due to alterations of blood cells and plasma components, may play a role in the pathogenesis of microcirculatory disorders. An impaired availability of nitric oxide, related to polymorphisms in NOS3, the gene for endothelial cell nitric oxide synthase, might influence erythrocyte deformability. We undertook this study to investigate the hemorheologic profile in SSc and the role of NOS3 polymorphisms in modulating the hemorheologic status of SSc patients.MethodsWe studied 113 consecutive SSc patients (75 with limited cutaneous SSc [lcSSc] and 38 with diffuse cutaneous SSc [dcSSc]) and 113 healthy controls. The hemorheologic profile was obtained by assessing whole blood viscosity (WBV; at shear rates of 0.512 and 94.5 seconds−1), plasma viscosity (PLV; at a shear rate of 94.5 seconds−1), and erythrocyte deformability index (DI). We determined NOS3 polymorphisms by molecular analysis.ResultsA marked alteration of hemorheologic parameters was found both in patients with lcSSc and in those with dcSSc compared with controls (P < 0.0001). In multivariate analysis, rheologic variables were significantly associated with the disease (for WBV at a shear rate of 94.5 seconds−1, odds ratio [OR] 5.4, 95% confidence interval [95% CI] 1.4–19.9, P = 0.01; for PLV, OR 2.8, 95% CI 1.2–6.5, P = 0.01; for DI, OR 3.9, 95% CI 1.4–10.8, P = 0.007), and NOS3 −786C and 894T alleles significantly affected the DI (for −786C allele, OR 2.3, 95% CI 1.01–5.4, P = 0.04; for 894T allele, OR 2.2, 95% CI 1.01–4.8, P = 0.04). The simultaneous presence of the −786C and 894T alleles represented a susceptibility factor for SSc (OR 2.8, 95% CI 1.4–5.7, P = 0.004).ConclusionOur findings document an altered rheologic profile in SSc and demonstrate a relationship between this alteration and NOS3 polymorphisms, thus shedding light on a potential novel mechanism influencing the microcirculation in this disease.
Salivary gland epithelial cells: A new source of the immunoregulatory hormone adiponectin
Authors: Katsiougiannis Stergios , Kapsogeorgou Efstathia K. , Manoussakis Menelaos N. , Skopouli Fotini N. 
Published: June 2006

AbstractObjectiveAdiponectin is an adipocytokine that displays insulin‐sensitizing and immunoregulatory properties. Adipocyte development in association with fibrosis is frequently detected in primary Sjögren's syndrome lesions, connoting a healing process. The aim of this study was to examine the expression of adiponectin in minor salivary gland biopsy specimens obtained from patients with primary SS and controls.MethodsThe expression of adiponectin in minor salivary gland biopsy specimens and in long‐term–cultured non‐neoplastic salivary gland epithelial cell (SGEC) lines obtained from patients with primary SS and control subjects was examined, using immunohistochemistry and immunoblotting, respectively. The expression of adiponectin, adiponectin receptor 1 (AdipoR1), and AdipoR2 messenger RNA (mRNA) by SGECs was investigated by reverse transcription–polymerase chain reaction.ResultsImmunohistochemical analysis for adiponectin revealed positive staining of adipocytes from primary SS lesions as well as ductal epithelial cells from both patients with primary SS and controls. All of the SGEC lines tested were shown to express adiponectin, AdipoR1, and AdipoR2 mRNA, whereas adiponectin protein expression was detected by immunoblotting in SGECs from patients with primary SS but not in those from controls. The analysis of concentrated culture supernatants also revealed increased adiponectin expression by SGECs from patients with SS compared with controls.ConclusionOur findings provide novel evidence that adiponectin is produced by SGECs. The high constitutive expression of adiponectin by SGECs from patients with primary SS is likely attributable to aberrant activation of these cells. Although the significance of adiponectin expression remains unknown, it is possible that adiponectin functions in an autocrine manner, as suggested by concurrent expression of the relevant receptors.