bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis by mass spectrometry of the hydrolysis/condensation reaction of a trialkoxysilane in various dental monomer solutions
Authors: Farahani Mahnaz , Wallace William E. , Antonucci Joseph M. , Guttman Charles M. 
Published: December 2005

Abstract3‐Methacryloxypropyltrimethoxysilane (MPTMS) was converted to silsesquioxane oligomers by hydrolysis/condensation in three dental monomer solutions. The molecular mass distribution and molecular structures of these oligomers was studied by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. Each dental monomer imparted distinct characteristics on the oligomeric silsesquioxane produced. Ethoxylated bisphenol A dimethacrylate (EBPADMA) produced low‐mass oligomer silsesquioxanes that showed complete hydrolysis and a very high degree of intramolecular condensation (i.e., there were no methoxy and few silanol groups remaining on the oligomers). 1,6‐Bis(methacryloxy‐2‐ethoxycarbonylamino) 2,4,4‐trimethylhexane also produced fully hydrolyzed oligomeric silsesquioxanes but with twice the average molecular mass as the EBPADMA. Finally, triethylene glycol dimethacrylate produced higher mass oligomeric silsesquioxanes than EBPADMA even though it showed incomplete hydrolysis. The degree of hydrolysis increased with increasing mass, as did the degree of intramolecular condensation. Oligomers with degrees of polymerization below 8 were poorly hydrolyzed and showed little if any intramolecular condensation. Those with degrees of polymerization of 9 or greater were almost completely hydrolyzed with a high level of intramolecular condensation. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1842–1847, 2006
Study on the interfacial properties of two‐dimensionally arranged glass fiber/epoxy resin model composites
Authors: Moon C. K. , Holmes G. A. , McDonough W. G. 
Published: December 2005

AbstractThe effect of interfiber distance on the interfacial properties in two dimensional multi‐E‐glass fiber/epoxy resin composites has been investigated using fragmentation test. In addition, the effect of the fiber surface treatment on the interfacial properties has been studied. We found that the interfacial shear strength decreased with the decreasing interfiber distance at the range of <50 μm and the extent of the decreasing was more serious as the increasing of the number of adjacent fiber. This is probably that the interface between the fiber and the resin was damaged by the breaking of adjacent fibers and the damage increased with minimizing the interfiber spacing and the number of adjacent fibers. We can guess that interfacial shear strength in real composites is much smaller than that of multifiber fragmentation sample with touched fiber. When the interfiber distance was >50 μm, the interfacial shear strengths were saturated regardless of fiber surface treatment and were in close agreement with those of the single fiber fragmentation test. Finally, the interfacial shear strength evaluated using two dimensional fragmentation tests are shown as real values in‐site regardless of fiber surface treatment, interfiber distance, and existing matrix cracks. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1541–1551, 2006
Enhancement of electrical properties of anisotropically conductive adhesive joints via low temperature sintering
Authors: Li Yi , Moon Kyoung‐Sik , Wong C. P. 
Published: December 2005

AbstractThe electrical properties of anisotropically conductive adhesives (ACAs) joints through low temperature sintering of nano silver (Ag) particles were investigated and compared with that of the submicron‐sized Ag‐filled ACA and lead‐free solder joints. The nano Ag particles used exhibited sintering behavior at significantly lower temperatures (<200°C) than at the bulk Ag melting temperature (960°C). The sintered nano Ag particles significantly reduced the joint resistance and enhanced the current carrying capability of ACA joints. The improved electrical performance of ACA was attributed to the reduced interfaces between the Ag particles and the increased interfacial contact area between nano Ag particles and bond pads by the particle sintering. The reduced joint resistance was comparable to that of the lead‐free (tin/3.5 silver/0.5 copper) metal solder joints. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1665–1673, 2006
Effects of zinc oxide nanoparticles on the physical properties of polyacrylonitrile
Authors: Chae Dong Wook , Kim Byoung Chul 
Published: December 2005

AbstractPolyacrylonitrile (PAN)/zinc oxide (ZnO) nanocomposites were prepared by solution mixing in dimethylacetamide, followed by film casting, and their physical properties were investigated. The heating scan of differential scanning calorimetry displayed only a single crystallization peak (Tc) without a melting peak, regardless of the presence of ZnO. The incorporation of ZnO nanoparticles decreased Tc by 13°C, and increased the heat of crystallization by 18%. Further, it greatly improved the thermal stability of PAN, even at the ZnO content as low as 0.1 wt %. The nanocomposites showed the UV transmittance peak at 365 nm, whose intensity was increased as ZnO content was increased. The presence of ZnO did not produce new peak nor shift the peaks with respect to PAN in wide angle X‐ray diffraction pattern. Introduction of a small amount of ZnO nanoparticles did not have notable effect on the tensile properties. However, 5 wt % loading of the nanoparticles increased the tensile modulus of PAN by 14.5% and decreased elongation at break dramatically. PAN nanocomposites with 5 wt % ZnO did not show any plateau region in stress–strain curve. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1854–1858, 2006
Comparative effects of pyrolyzed oil shale and pyrolyzed burned oil shale used as fillers in poly(ethylene‐co‐vinyl alcohol)
Authors: Barbosa Ronilson Vasconcelos , Baumhardt‐Neto Ricardo , Mauler Raquel Santos , Lima Éder Cláudio , Schneider Cláudia Gazzana 
Published: December 2005

AbstractPyrolyzed oil shale (POS) obtained from the pyrolysis of bituminous rock was burned in a normal atmosphere (POSB) to remove the organic phase and then used as a filler in poly(ethylene‐co‐vinyl alcohol) (EVAL). The effects of vinyl alcohol content, POSB particle size, and POSB concentration on the composite were investigated through measurement of mechanical properties. Composites were prepared in a rotor mixer at 180°C. Stress–strain plots of compression‐molded composites showed synergic behavior of the mechanical properties with low concentrations (1–5 wt %) of POSB, regardless of particle size or type of EVAL. Such behavior suggests close packing and strong interactions between inorganic filler and polymer, with the effects reinforced by the mechanical properties. It was observed that the absence of the organic phase in the modified material improved the mechanical properties of the composites. Increasing the vinyl alcohol content improved the compatibility between polymer and filler in the EVAL/POS but did not affect the compatibility in EVAL/POSB composites. The relationship of mechanical and morphological behavior in the EVAL/POS and EVAL/POSB composites indicated that different factors were at play to explain the compatibility between the EVAL and the inorganic phase. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1859–1864, 2006
Structure and properties of polyamides‐epoxidized elastomers blends
Authors: Steller Ryszard , Micewicz Ewa , Meissner Wanda , Piglowski Jacek , Haponiuk Józef 
Published: December 2005

AbstractBlends of aliphatic polyamides (PA6, PA66, and PA12), containing 0–15 wt % nonepoxidized or epoxidized elastomers (statistical copolymer butadiene–styrene BS/EBS or linear block copolymer styrene–butadiene–styrene SBS/ESBS) were investigated. For PA6‐elastomer blends, taken as an example, it was shown that with increasing blending time, mechanical properties of blends increase, especially, if ESBS copolymer is used. It can be treated as an indirect sign of reactions between components. It was also found that in blends considerable changes of glass temperatures of components occur. Polyamides in blends with elastomers have smaller heats of fusion in comparison with virgin polyamides. It testifies to hindering of PA crystallization by elastomers. In some cases, significant shifts of melting points are also observed. Measurements of water contact angle show that all blends have very similar values of contact angles, which are lower than those of virgin polyamides. Elastomer content does not also affect the blend water uptake. However, it depends on the polyamide and elastomer type contrary to contact angle. Highest water uptake changes are observed in blends of PA66, especially for epoxidized elastomers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1872–1879, 2006
The preparation, characterization, and cure reactions of new bisbenzocyclobutene‐terminated aromatic imides
Authors: Zhang Yingqiang , Gao Jianying , Shen Xuening , Huang Farong 
Published: December 2005

AbstractSeveral new bisbenzocyclobutene‐terminated aromatic imides, 2,2′‐bis(N‐4‐benzocyclobutenyl) phthalimide, 2,2′‐bis[4‐(N‐4‐benzocyclobutenylphthalimide)]‐ether, 2,2′‐bis[4‐(N‐4‐benzocyclobutenylphthalimide)]‐ketone, and 2,2′‐bis[4‐(N‐4‐benzo cyclobutenylphthalimid‐4‐oxy) phenyl]‐propane, have been synthesized in high yields and characterized by FTIR, MS, EA, and 1H NMR spectroscopy. The polymers cured from benzocyclobutene‐terminated imides have high glass transition temperature and good thermal stabilities. The cure reaction of an imide was studied by FTIR‐ATR (attenuated total reflection) and DSC techniques. Apparent kinetic parameters of the cure reaction are obtained. The apparent cure reaction order, activation energy, and pre‐exponential factor determined by isothermal DSC method are 1, 143.4 kJ/mol, and 3.88× 1013 min−1, and by nonisothermal DSC methods 1, 139.4 kJ/mol, and 2.27× 1013 min−1, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1705–1719, 2006
Modification of polyethylene and incorporation of fillers for effective reinforcement of mechanical and better flame retardant properties
Authors: Shah Gul Bali , Fuzail Mohammad 
Published: December 2005

AbstractThe effect of incorporation of the two different fillers, i.e. calcium carbonate and magnesium hydroxide, over a concentration range of 0–35% w/w on mechanical and burning properties and hot set test of polyethylene (PE) has been studied. The incorporation of either of these fillers deteriorates mechanical properties such as percent elongation at break and tensile strength of PE. However, modification of PE not only mitigates the reduction in these properties, but brings enhancement in all the aforementioned properties. A clear difference in these properties for the incorporation of each of these fillers to just PE, silane‐grafted but uncured PE, and silane cross‐linked PE has been found. These properties follow the order of superiority as: cross‐linked PE > silane‐grafted uncured PE > physically filled PE. The different properties due to physical bonding of filler, physical bonding in the presence of polar silane grafted onto PE, and that of chemical bonding of filler in cross‐linked PE has been discussed and analyzed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1928–1933, 2006
Copolymerization of acrylonitrile with methyl vinyl ketone
Authors: Hou Chen , Liu Junshen , Ying Liang , Wang Chengguo 
Published: December 2005

AbstractMethyl vinyl ketone (MVK) was first used to successfully copolymerize with acrylonitrile (AN). This was achieved with azobisisobutyronitrile as the initiator. The kinetics of the copolymerization of AN with MVK were investigated in a H2O/dimethyl sulfoxide (DMSO) mixture between 50 and 70°C under N2 atmosphere. The rate of copolymerization was measured. The kinetic equation of the copolymerization system was obtained, and the overall activation energy for the copolymerization system was determined. The values of the monomer apparent reactivity ratios were calculated by the Kelen–Tudos method. In a DMSO‐rich reaction medium (DMSO/H2O > 80/20), the monomer apparent reactivity ratios were similar to those in the solution polymerization system. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1940–1944, 2006
Synthesis and characterization of high molecular weight metaloquinolate‐containing polymers
Authors: Mei Qunbo , Du Naiying , Lu Mangeng 
Published: December 2005

AbstractIn this article, a new method to synthesize novel metaloquinolate (AlQ3, ZnQ2)‐containing polymers is reported. A model polymer with 8‐hydroxyquinoline ligands can be obtained by free‐radical copolymerization with methyl methacrylate (MMA), then metaloquinolate (AlQ3, ZnQ2)‐containing polymers are prepared by coordinating reaction with di(8‐hydroxyquinoline) aluminum (AlQ2) chelates or mono (8‐hydroxyquinoline) zinc (ZnQ) chelates without crosslinking. The structures of products are confirmed by NMR, FTIR, ultraviolet‐visible, elementary analysis, photoluminescence spectrum, and gel permeation chromatography analysis. They are soluble in common solvents and suitable to form films. The use of AlQ2 and ZnQ avoided the crosslinking caused by the AlQ3, ZnQ2 formation between different polymer chains. Different from the traditional small organic molecules in organic light‐emitting diodes (OLEDs) fabrication, the polymer can be processed by spin coating without phase separation. Compared to the PMMA or MMA‐co‐HEMA‐CH2‐Hq, the Tg of the metaloquinolate‐containing polymers was much higher. It should be of interest for OLED applications. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1945–1952, 2006
Effects of organoclay modification on microstructure and properties of polypropylene–organoclay nanocomposites
Authors: Lee Jin Woo , Kim Mun Ho , Choi Won Mook , Park O Ok 
Published: December 2005

AbstractWe prepared polypropylene nanocomposites based on a modified organoclay with isobutyl trimethoxysilane to investigate the effects of such modifications of organoclay on the microstructure and properties of the nanocomposite. The organoclay was preliminarily intercalated with distearyldimethylammonium bromide via an ion exchange before being grafted with silane. The morphology of the polypropylene–organoclay nanocomposites was characterized by wide‐angle X‐ray diffraction analyses and transmission electron microscopy. The modification of the edges of clay platelets with organic silane resulted in a more uniform dispersion of nonagglomerated tactoids, which consisted of several intercalated clay platelets. However, the unmodified organoclay led to a mixed morphology with both agglomerated and nonagglomerated tactoids. The grafting of the clay edges with organic silane also affected the linear viscoelastic properties of the nanocomposites in the melt state, which was shown to be sensitive to the interaction between the edges of clay platelets as well as to the interaction of the polymer with the platelet edges. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1752–1759, 2006
Thermal properties measurements of renatured gelatin using conventional and temperature modulated differential scanning calorimetry
Authors: Dai Chi‐An , Chen Yi‐Fan , Liu Ming‐Wei 
Published: December 2005

AbstractThe thermal properties of amorphous gelatin films and gelatin films with renatured structural order were measured by using conventional and temperature modulated differential scanning calorimetry (DSC). Different amounts of gelatin structural order associated with a melting enthalpic change in the DSC measurement were prepared based on different gelatin drying conditions. Two consecutive heating and cooling DSC measurements on the gelatin films showed that there was no change in the glass‐transition temperature (Tg) for the amorphous gelatin but there was a decrease in the Tg for the structural gelatin on the second DSC scan. This decrease was attributed to the plasticizing effect from the release of originally hydrogen‐bonded water associated with the structural gelatin. In addition, a reversing endotherm observed upon melting of the structural gelatin during a temperature modulated DSC measurement indicated that the transition of bound water to free water occurred as the partial triple‐helix gelatin melted. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1795–1801, 2006
Optimum temperature profile for noncatalytic reaction to produce polyamide hot melt adhesives
Authors: Heidarian J. , Ghasem N. M. , Wan Daud W. M. A. 
Published: December 2005

AbstractFoaming is a general problem in the manufacturing of fatty polyamides. It is mainly affected by the mixing rate and reaction temperature. The effect of the reaction temperature and rate of mixing on foaming are investigated. Time minimization for the polyamidation reaction to prevent foaming is performed. The process constraints are the rate of temperature increase and the rate of the production of water. It is found that with an increase in the mixing rate, foaming starts at lower temperatures and with a decrease in the mixing rate, foaming only starts at high temperatures. For each mixing rate, with an increase in the temperature, the duration of foaming is shorter because the increase in the rate of foaming ends. Temperature profiles with time for different mixing rates are generated, and it is found that the reaction time decreases with increasing mixing rate. The generated temperature profiles are verified experimentally, and no foaming is observed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1817–1822, 2006
Ethylene polymerization by phenylenedimethylene‐bridged homobinuclear zirconocene/methylaluminoxane systems
Authors: Sun Junquan , Liu Xijie , Zhang Haiying , Xiao Xiaohui , Lin Feng , Schumann Herbert 
Published: December 2005

AbstractIn the presence of methylaluminoxane (MAO), ethylene polymerization was successfully performed with homobinuclear zirconocene complexes {[(C5H5)ZrCl2](C5H4CH2 C6H4CH2C5H4)[(C5H5)ZrCl2]; 3o, 4m, and 5p}, which were prepared conveniently by the reaction of disodium(phenylenedimethylene)dicyclopentadienide [C6H4(CH2C5H4Na)2] with 2 equiv of (N5‐Cyclopentadienyl)trichlorozirconium dimethoxyethane (CpZrCl3(DME)) in tetrahydrofuran and characterized by 1H‐NMR and elemental analysis. The effects of the polymerization parameters, such as the temperature, time, concentration of the catalyst, MAO/catalyst molar ratio, and isomeric difference of the homobinuclear metallocene complexes 3o, 4m, and 5p were studied in detail. The results showed that all three catalytic systems had moderate activities in ethylene polymerization and afforded polyethylene with relatively broad polydispersities. The catalytic activity of 4m was somewhat higher than that of 3o and 5p but lower than that of 4,4′‐bis(methylene)biphenylene‐bridged zirconocene catalysts; this indicated that the distance between the two metal centers was too short in comparison with a 4,4′‐bis(methylene)biphenylene bridge to increase the catalytic activity. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Use of self‐management behaviors to cope with rheumatoid arthritis stressors
Authors: Katz Patricia P. 
Published: December 2005

AbstractObjectiveTo examine self‐management behaviors used to cope with 5 rheumatoid arthritis (RA)‐related stressors (pain, fatigue, physical limitations, joint changes, and symptom unpredictability) and the relationship between use of self‐management behaviors and ability to perform life activities.MethodsData were from telephone interviews of 511 persons with RA. Participants were presented with lists of self‐management behaviors for each stressor and asked to indicate which they had used in the past year. Performance of life activities was assessed concurrently (baseline) and 1 year later (followup). The number of activities affected (difficulty performing or unable to perform) and the number that individuals were completely unable to perform were calculated. Multiple regression analyses were used to examine the association of perceived stressor impact and arthritis education with strategy use and the association of self‐management behaviors with performance of life activities.ResultsFour self‐management strategies were identified: accommodation, active remediation, social, and perseverance. Greater perceived impact of stressors was associated with use of more self‐management strategies in total for each stressor (β = 0.43–0.73, all P < 0.0001) and with use of accommodation (β = 0.26–0.29, P < 0.0001), social (β = 0.23–0.43, P < 0.0001), and perseverance (β = 0.29–0.46, P < 0.0001) strategies. Greater use of accommodation strategies at baseline was associated with an increase in the number of activities affected at followup (β = 0.11, P < 0.05); greater use of perseverance strategies was associated with a decrease in activities unable to perform (β = −0.13, P < 0.01).ConclusionSelf‐management behaviors are commonly used and may help prevent loss of the ability to perform life activities.
Calcium pyrophosphate deposition disease mimicking polymyalgia rheumatica: A prospective followup study of predictive factors for this condition in patients presenting with polymyalgia symptoms
Authors: Pego‐Reigosa Jose M. , Rodriguez‐Rodriguez Maria , Hurtado‐Hernandez Zaraida , Gromaz‐Martin Jaime , Taboas‐Rodriguez Daniel , Millan‐Cachinero Carlos , Hernandez‐Rodriguez Iñigo , Gonzalez‐Gay Miguel A. 
Published: December 2005

AbstractObjectiveTo assess the characteristics of calcium pyrophosphate deposition disease (CPDD) with proximal involvement mimicking polymyalgia rheumatica (PMR), and to identify the best predictive factors for the presence of a clinical pattern of CPDD in patients presenting with polymyalgia symptoms.MethodsPatients diagnosed with either PMR or CPDD at the Rheumatology Division of Hospital Meixoeiro (Vigo, Spain) over a 7‐year period (1997–2003) were prospectively followed for at least 12 months.ResultsThe study group comprised 118 patients with PMR features and 112 patients with CPDD. Eighty‐two of the 118 patients with PMR manifestations were diagnosed as having pure PMR, and 36 met the diagnostic criteria for both PMR and CPDD. Patients with CPDD mimicking PMR were older (P = 0.02) and had peripheral arthritis more frequently (P = 0.004) than those with pure PMR. Radiologic osteoarthritic changes in the hands and knees, including more advanced radiologic grade of knee osteoarthritis, and tendinous calcifications were more frequent in patients with PMR/CPDD (P < 0.001). The best predictive factors for the occurrence of this atypical pattern of CPDD in a patient presenting with PMR features were the age at diagnosis and the presence of tibiofemoral osteoarthritis, tendinous calcifications, and ankle arthritis.ConclusionInvolvement of proximal joints may be the clinical presentation of CPDD. CPDD should be included in the spectrum of diseases mimicking PMR. The presence of tibiofemoral osteoarthritis, tendinous calcifications, and ankle arthritis are clues that may alert the clinician to the presence of CPDD in an elderly patient presenting with PMR manifestations.