bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nickel coated mica for conductive compounds
Authors: Gilbert M. , Kandasubramanian B. 
Published: June 2003

AbstractIt has been shown that nickel coated mica will function as a conductive filler in ABS compounds. The coating process has been optimised by investigation of PdCl2 (catalyst) concentration, coating temperature and pH and activator. Using a coating temperature of 90°C and a pH of 5, conductive mica powders coated with thin uniform layers of nickel have been produced.
The effect of compatibilizing and coupling agents on the mechanical properties of glass bead filled PP/PET blends
Authors: Arencón David , Maspoch Maria Lluïsa , Velasco José Ignacio 
Published: June 2003

AbstractPP/PET blends (95/5) filled with 50% by weight of glass beads were prepared and studied at morphological and mechanical level, and compared with its analogous samples of glass bead‐filled PP. The influence of a compatibilizing agent (maleic anhydride grafted polypropylene) and different silane coupling agents was analysed. It has been found that PET embeds glass bead surface independently on the silane coupling agent employed. Addition of MAPP in PP/PET blends leaded to tensile strength values similar to those of unfilled PP, but rupture takes place in a brittle manner.
Preliminary studies on the surface layer of starch
Authors: Bieliński Dariusz , Pysklo Leszek , Dul Jan , Ślusarski Ludomir , Janowska Grażyna , Lewandowicz Grażyna 
Published: June 2003

AbstractCharacterization of the surface layer of starch powder, originated from potato or maize, was carried out applying various experimental techniques: Fourier‐transformed infrared internal reflection spectroscopy (FTIR‐IRS), inverse gas chromatography (IGC) and scanning electron microscopy (SEM). The main kinds of starch were studied as potential fillers for rubber and results discussed in terms of factors requiring modification to improve starch miscibility and activity towards rubber. Starch of high amylopectine content shows surface enrichment with amylose what makes crystallinity of the surface layer higher than in bulk of the material. Particles of the both kinds of starch have very smooth surface (morphological index, Im = 0.995), highly resistant to its geometrical development. Dispersive component of the surface energy of starch was found to be similar to that of low energy polymers (γsd = 32.5 mJ/m2 at 23°C) and its surface to be of electron‐donor character.
Processing of polypropylene ‐ clay hybrids
Authors: Boucard S. , Duchet J. , Gérard J.F. , Prele P. , Gonzalez S. 
Published: June 2003

AbstractPolypropylene compounds containing organophilic layered silicates were prepared by means of melt extrusion at 180°C. We have studied the effect of the coupling agent on morphology development and mechanical properties. We are convinced of the importance of both the chemistry and the process conditions to elaborate nanocomposites with optimized properties.
Silica nanofillers ‐ preparation and characterization
Authors: Jesionowski Teofil 
Published: June 2003

AbstractStudies were conducted on formation of monodisperse silicas from sodium metasilicate and hydrochloric acid solutions in emulsion medium. Non‐ionic surfactants were used as emulsifiers. Physicochemical parameters of the precipitated silicas were determined, including particle size, polydispersity, structure and shape of particles. Moreover, specific surface area (BET) and porosity were characterized. Silica of optimum physicochemical parameters, i.e. of the ideally spherical particle shape, monodisperse character was obtained using a homogenization technique during precipitation and Rokafenol N‐3/N‐6 surfactant mixture as emulsifiers.
Fumed silica synthesis. Influence of hydrogen chloride on the fumed silica particle formation process
Authors: Khavryutchenko Alexey V. , Khavryutchenko Vladimir D. 
Published: June 2003

AbstractInteraction of silicon dioxide molecule up to the small silica protoparticle and primary particle formation, and influence of hydrogen chloride (HCl), water (H2O) and inert molecules (nitrogen N2) “under flame condition” and “after cooling” on structure and properties of fumed silica were investigated by quantum‐chemical simulations. An attempt to give definition of surface concept on atomic level was made.
Thermomechanical degradation of filled polypropylene
Authors: La Mantia F.P. , Tzankova Dintcheva N. 
Published: June 2003

AbstractThe main problem in post‐consumer plastics recycling is due to the thermomechanical stress acting on the melt during the reprocessing operations. The macromolecules break because of the temperature and of the mechanical stress. The extent of degradation is then correlated to the level of mechanical stress which, in turn, is proportional to the viscosity of the melt. The presence of fillers increases the viscosity of the polymers and then it is expected that the level of thermomechanical degradation of these systems is larger than that of the unfilled material.In this work the thermomechanical degradation kinetic of a polypropylene sample is investigated as a function of the calcium carbonate content. It is shown that the decrease of viscosity, that is the decrease of molecular weight, is directly related to the increase of viscosity due to the filler content. The worsening of the mechanical properties are consistent with the change of viscosity.
Characterisation of filled and recycled PA6
Authors: Maspoch Maria Lluïsa , Ferrando Haritz Eder , Velasco José Ignacio 
Published: June 2003

AbstractFilled PA6 are important representatives of engineering plastics used in automotive components. Nowadays, the demand of plastic recycled grades is increasing in this branch of industry but polymer recycling can undergo thermomechanical degradation processes with the results of a poor secondary material, regarding its properties. In this paper an investigation of thermal, mechanical (tensile, flexural and impact tests) and rheological properties of a sample of recycled and filled PA6, is reported as a function of the number of reprocessing operations (3 times) and of the fraction of recycled material (15, 30 and 50%) added to the virgin material. Recycled PA6, used in this study, comes from fibre grade production waste. Material was filled with 20% glass beads and 10% glass fibre, according to the specifications of the application, mainly to obtain a lower shrinkage in the end product. This work also shows that the mineral fraction, not being degraded during the injection process, allows better recyclability to the filled material. The properties of the recycled material remain below the virgin, and the best combination of both appears to be the mixture with 30w.% recycled fraction, which shows a lost of properties similar to 3 reprocessing operations.
The use of Flory‐Huggins parameters to characterization of polymer/filler interactions
Authors: Milczewska Kasylda , Voelkel Adam , Jeczalik Jerzy 
Published: June 2003

AbstractAny quantitative information on the strength of interactions between inorganic filler and polymer is substantial for the future application of the composite. The magnitude of adhesion of two phases may be deduced from results collected by various experimental techniques. Inverse gas chromatography is very simple and precise method.Authors propose to express the magnitude of modified filler/polymer interactions by Flory‐Huggins χ23 parameter. We investigated polyether‐urethane/3‐mercaptopropyltrimethoxysilane systems containing different amount of filler (5, 10, 20 wt%).Moreover, information on the physico‐chemical status of oligomer and modified silicas were presented with the use of the following parameters:• solubility parameter δ2 and its components describing properties of the polymer layer;•Flory‐Huggins parameter χ12 which describes polymer‐solute or filled polymer‐solute interactions.Subscripts 1, 2, 3 and m refers to solute, polymer, filler and polymer/filler mixture, respectively. Pure, low molecular weight, volatile test solutes were selected and injected into a chromatographic column.The influence of the IGC experiment, temperature, the content of modified silica and the nature of test solute on the evaluated parameters are presented and discussed.
New type of inorganic filler with a core‐shell structure
Authors: Owczarek Magdalena , Zaborski Marian , Paryjczak Tadeusz , Boiteux Gisele , Gain Olivier 
Published: June 2003

AbstractWe tried to use a new kind of filler with “core‐shell” structure as a crosslinking agent for carboxylated butadiene‐acrylonitrile rubber. We thought that the substance would be better dispersed in the polymer matrix than zinc oxide. Silica (ZnO/SiO2) whose surface was modified with amorphous zinc oxide from zinc nitrate was used. Its properties were investigated using gas chromatography.Finally we obtained unconventional networks containing ionic and complex bonds (as a result of reaction of elastomers' functional groups i.e. carboxyl groups with the appropriate neutralizing agent as metal oxide). Ionic clusters were formed in vulcanizates which influenced the mechanical properties and crosslinking efficiency. We confirmed the presence of these unconventional bonds by IR spectroscopy and DMTA analyses.
Synthesis of silica in elastomer's matrix
Authors: Pietrasik Joanna , Zaborski Marian , Boiteux Gisele , Gain Olivier 
Published: June 2003

AbstractWe tried to synthesise silica's fillers in polar and nonpolar elastomers. Di‐, tri‐ and tetraalkoxysilanes were used as a precursor of silica. Such functionality allowed us to obtain a filler with different ratio of crosslinking. We could expect some interactions between elastomer and silanes, which contained additional functional groups. We investigated vulcanizates by using the following methods: crosslink density in toluene and 10% solution of ethylenediamine in toluene, mechanical properties, IR microscopy, DMA. It appeared that alkoxysilanes influenced advantageously on elastomers and properties.
Synthesis and modification of fillers with derivatives of benzoic acids
Authors: Tyburczy Michał , Zaborski Marian , Baryń Włodzimierz 
Published: June 2003

AbstractThe subject of this research work was an effect of liquid crystals on the properties of filled elastomer systems. Both commercially available and own synthesized liquid crystals were used. The elastomer was ethylene‐propylene rubber, while precipitated silica and calcium carbonate were used as fillers. The liquid crystals were deposited on the surface of the fillers from solution. Their effect on the mechanical properties of the vulcanizates was studied.
Comparative characteristics of local and foreign bentonites
Authors: Wieczorek Michał , Krysztafkiewicz Andrzej , Jesionowski Teofil 
Published: June 2003

AbstractComparative analysis was performed of local bentonites of SPECJAL EXTRA U and IZOL types, produced by Zakłady Górniczo‐Metalowe Zębiec, and of LT type bentonite, produced by Rheox company. Principal physicochemical properties of the bentonites were established, including bulk density, capacities to absorb water, dibutyl phthalate and paraffin oil and their sedimentation rates in water, xylene and gasoline were estimated. Bentonite morphology was examined using scanning electron microscope (SEM). Moreover, particle size distribution, BET surface area and zeta potential were determined.
Elasticity of fractal filler networks in elastomers
Authors: Klüppel Manfred 
Published: June 2003

AbstractThe role of filler networking in the elastic properties of elastomer composites is investigated by means of a fractal approach to filler aggregation in high viscosity media and a linear elastic model of flexible chains of filler particles. The filler netwok is described by a space‐filling configuration of fractal filler clusters, resulting from a kinetic cluster‐cluster aggregation (CCA) process. The elastic modulus of the filler network is shown to fulfil a scaling relation with respect to filler concentration. The universal value 3.5 of the elasticity exponent reflects the fractal nature of the filler network. Experimental results on various elastomer composites with conventional‐ and model fillers (microgels) demonstrate that a corresponding scaling prediction for the small strain modulus is well fulfilled.
Cavitation and cavity‐free deformation of filled crystalline polymer systems
Authors: Galeski Andrzej , Bartczak Zbigniew 
Published: June 2003

AbstractMain mechanisms of tough response of polymers are described. In heterogeneous polymer systems due to mechanical misfit between heterogeneities and the matrix a high negative pressure (tri‐axial stress) is generated. The excessive negative pressure is the main reason of material cavitation. Cavitation appears to be another mechanism of tough response of the material to loading. Cavitation is a massive phenomenon in crystalline polymers and in all filled polymers. Cavitation itself does not consume much energy but allows for further toughening by activating other mechanisms. Examples of polypropylene filled with chalk modified by liquid, rubber and mineral filled polypropylene and syndiotactic polypropylene filled with chalk are described. Modes of deformation with significant compressive component of stress prevents for cavitation. Materials deformed in a cavity‐free manner show much higher strength. It is pointed out that high polymer crystal anisotropy is necessary for the formation of a network of easy crystallographic slip in the unusual toughening of highly filled polymers observed recently. An example of syndiotactic polypropylene filled with submicro‐chalk particles is presented.
Charge carrier transport in heterogeneous conducting polymer materials
Authors: Kryszewski Marian , Jeszka Jeremiasz 
Published: June 2003

AbstractThe similarities of conductivity mechanisms of composites and nanocomposites and doped conjugated polymers that are also characteristic of specific heterogeneity are discussed. It is shown that the formulae developed to account for internal heterogeneity of conductive polymers can be applied also for polymer composites in spite of low overall content of the conductive phase. For fully organic nanocomposites (reticulate doped polymers) showing metal‐like conductivity and a crossover temperature effective contribution of metallic phase is estimated. Examples of different properties of nanoparticles forming conducting networks as compared with the bulk crystals are discussed.
Activity of fillers in elastomer networks of different structure
Authors: Zaborski M. , Donnet J.B. 
Published: June 2003

AbstractThe paper deals with interactions between low molecular weight substances and silica. Activity of SiO2 towards ethylene‐propylene‐diene rubber (EPDM) also depends on the kind of crosslinking system used. Calcium carbonate, the filler exhibiting low interactions with elastomers does not show any changes in activity, due to application of different crosslinking systems. In our opinion, the observed increase of the fillers activity results from the modification of elastomer chains by crosslinking agents, influence of the latter on the formation of its own network (the so called “structure”) in the elastomer matrix, and above all from nanoheterogeneous distribution of network crosslinks in vulcanizates. The non Gaussian probably bimodal distribution of crosslinks is likely to influence positively properties of elastomers. A similar effect is observed in peroxide vulcanizates of EPM produced with the use of the crosslinking coagents of polar nature. Behaviour of different kinds of carbon black in natural rubber (NR) crosslinked with dicumyl peroxide (DCP), sulphur donors or sulphur with accelerators is discussed. Reinforcing action of carbon black, particularly the active ones, showed to be more effective in sulphur than in peroxide vulcanizates.
External management succession, human capital, and firm performance: an integrative analysis
Authors: Bailey Elizabeth E. , Helfat Constance E. 
Published: June 2003

AbstractEconomic analysis of human capital leads to a somewhat different question than that addressed by other management research on external succession: do differences between external successors in the transferability of their human capital affect firm performance, and if so, how? By comparing external successors that have within‐industry and related‐industry skills, we find that successors with less transferable (related‐industry) skills have greater variance of firm performance. Our analysis provides an example of the benefits of integrating economic concepts with empirical research in competitive strategy, on a topic of central concern in the traditional strategic management literature, namely, top executives. Copyright © 2003 John Wiley & Sons, Ltd.
The intermediation theory of the firm: integrating economic and management approaches to strategy
Authors: Spulber Daniel F. 
Published: June 2003

AbstractEconomic and management perspectives on management strategy can and should be integrated. The intermediation theory of the firm and models of market microstructure provide a basis for advancing the integration of management and economics perspectives. In particular, the theory allows for a combination of economic approaches such as Porter's work on competitive strategy with management approaches such as work on the abilities and resources of the organization. The article presents a unified strategy framework based on transaction costs and the intermediation theory of the firm. Copyright © 2003 John Wiley & Sons, Ltd.
Strategy as economics versus economics as strategy
Authors: Langlois Richard N. 
Published: June 2003

AbstractClearly, strategy and economics differ along one critical dimension: strategy is concerned descriptively with firms and normatively with the tasks of managers, whereas economics is concerned descriptively with the entire economic system and normatively with the efficiency of that system. Nonetheless, the overlap is considerable, and both management scholars and economists have ransacked economic thought for inspirations to strategic theory and managerial practice. This essay will examine and evaluate that enterprise. More interestingly, perhaps, it will suggest that perhaps the process ought to be reversed. Economics as it is now practiced would do well to learn from strategy. Copyright © 2003 John Wiley & Sons, Ltd.
The resource‐based tangle: towards a sustainable explanation of competitive advantage
Authors: Foss Nicolai J. , Knudsen Thorbjørn 
Published: June 2003

AbstractTo advance the RBV we propose separation of necessary and additional conditions for the expression of SCA. We argue that there are only two necessary conditions, namely uncertainty and immobility and that all other conditions are additional. Copyright © 2003 John Wiley & Sons, Ltd.
Why look for a mirage when you already have an oasis?
Authors: Pandian J. Rajendran , Robertson Paul L. 
Published: June 2003

AbstractThe theoretical elegance of economic theory in general has inspired many strategic management researchers to examine the possibilities of building theories of competitive strategy by applying economic principles to competitive decisions. In this paper, we argue that the integration of economic perspective is not feasible. Also, we argue that the theories built on strategic management perspectives are superior to those built on economic theory and hence we should not worry about integrating these two competing perspectives. We also point to the issues raised by these attempts at integration and point out the difficulties involved. Our arguments are supported by other researchers who have attempted to reconcile differences in various economic traditions. Hence, we ask why we should search for a mirage (though one might imagine it to be an oasis) while we are already at an oasis! Copyright © 2003 John Wiley & Sons, Ltd.
Integrating transaction costs theory and real options theory
Authors: Sanchez Ron 
Published: June 2003

AbstractThis paper develops an integration of transactions costs theory and real options theory that leads to a more complete representation of the problem of economic organizing. By recognizing the opportunity costs associated with internalization of specific‐use assets when flexible assets are also available, the integrated theoretical framework provides better insights into optimal strategies for configuring value chains under supply‐side and demand‐side uncertainty. This expanded model of economic organizing suggests four optimal strategies for configuring value chains and predicts four prevailing forms of economic organization under varying combinations of contracting (supply‐side) and market (demand‐side) uncertainty. Copyright © 2003 John Wiley & Sons, Ltd.
A subjectivist approach to strategic management
Authors: Fu‐Lai Yu Tony 
Published: June 2003

AbstractAcknowledging the shortcomings of contemporary research on the economics of strategy, this paper proposes a subjectivist approach to strategic management. This subjectivist perspective is originated in German economics and found its base in the Austrian school of economics. Based largely on the works on Max Weber, Alfred Schutz and Ludwig von Mises, this paper develops a subjective interpretation framework which is applied to various fields of strategic management: entrepreneurship, organisation, vertical integration, innovation, marketing and advertising. Copyright © 2003 John Wiley & Sons, Ltd.
Unraveling the resource‐based tangle
Authors: Peteraf Margaret A. , Barney Jay B. 
Published: June 2003

AbstractResource‐based theory (RBT) is a prime example of a theory that integrates a management perspective with an economics perspective. As such, its challenge is to keep its arguments logically consistent and clear, despite the risk of their becoming entangled, due to competing and possibly conflicting theoretical influences. We argue, in this paper, that to meet this challenge, it is essential to understand the limits to the domain of RBT. Unless RBT is understood as a resource‐level and efficiency‐oriented analytical tool, its contribution cannot be understood and appreciated fully. Incorporating aspects of economic theory that fall outside this domain will not increase its power and will only add to the confusion.Continued efforts to increase the analytic precision of RBT and to elaborate its economic logic, however, are worthwhile pursuits. To these aims, then, we provide a sharper definition of competitive advantage, linking this term to value creation and to demand side concerns. Similarly, we provide an economically meaningful definition of value and more precise definitions of critical resources and of economic rents. This allows us to trace a clearer trail of logic, consistent with both the management and the economics perspectives, leading from critical resources to the generation of rents. Copyright © 2003 John Wiley & Sons, Ltd.
The emergent knowledge‐based theory of competitive advantage: an evolutionary approach to integrating economics and management
Authors: Coff Russell W. 
Published: June 2003

AbstractThis article explores the intersection of management and economics in the strategic management literature. Specifically, it examines knowledge‐based advantages from management and economics perspectives to highlight differences in explanations of: (1) the source of an advantage, (2) determinants of sustainability of an advantage, and (3) the factors that predict rent appropriation patterns from a competitive advantage.I conclude that both perspectives contribute to our understanding of why firms perform differently. Furthermore, the gradual or evolutionary integration that has occurred over time is effective and efficient for exploring the nature of strategic management problems. Finally, the dynamic competitive and technological environment will continue to yield new opportunities for integration of theoretical approaches. Copyright © 2003 John Wiley & Sons, Ltd.