bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conifer fibers as reinforcing materials for polypropylene‐based composites
Authors: Chuai Chengzhi , Almdal Kristoffer , Poulsen Lars , Plackett David 
Published: August 2002

AbstractConifer fibers were used to reinforce polypropylene (PP). To improve the compatibility between the conifer fibers and the PP matrix, the fibers were either grafted with maleated PP (MAPP), treated by adding MAPP, or mixed with ethylene/propylene/diene terpolymer (EPDM). The treatments resulted in improved processing, as well as improvements in the thermal and mechanical properties of the resultant composites compared with the composites filled with untreated conifer fibers. Moreover, MAPP grafting and MAPP treating displayed more obvious benefits than EPDM treating in terms of thermal properties, processing flowability, and tensile strength improvements. EPDM treating also produced more significant benefits than either MAPP grafting or MAPP treating in terms of impact strength and tensile elongation improvements. These improvements were attributed to surface coating of the fibers when EPDM was used. In addition, the effect of the concentration of the conifer fibers on the properties of the composites and the difference between MAPP grafting and MAPP treating were evaluated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2833–2841, 2001
Rheological behavior and processability of polypropylene blends with rubber ethylene propylene diene terpolymer
Authors: López Manchado Miguel A. , Biagiotti Jerico , Kenny José M. 
Published: August 2002

AbstractA study of the dynamic complex and steady shear viscosity of isotactic polypropylene (iPP), ethylene–propylene diene terpolymer rubber (EPDM) and three different blends of both polymers are presented over a range of temperatures and frequencies. Moreover, the processability of these materials is studied through torque measurements during blend mixing. The results obtained show that the viscosity gradually increases with rubber content in the blend and decreases with both temperature and frequency. Plots of η″ versus η′ (Cole–Cole plots) show that the blend with the lower rubber content (25%), has a certain rheological compatibility with neat PP. Furthermore, torque curves measured during blend mixing confirm these results, demonstrating that the blend with 25% of elastomer has a similar behavior of iPP during processing. To analyze the morphological structure of the blends, a dynamic mechanical analysis of the solid state is also presented. It is observed that the blends have two distinct values of Tg close to the corresponding values of the pure polymers, confirming that this type of blends based on a semicrystalline polymer and an amorphous elastomer forms a two‐phase system with a limited degree of miscibility between both components. In addition, the polymer present with the higher concentration forms the continuous phase and controls the rheological properties of the blend. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1–10, 2001
Dissolution/reprecipitation: A model process for PET bottle recycling
Authors: Poulakis J. G. , Papaspyrides C. D. 
Published: August 2002

AbstractA dissolution/reprecipitation route was followed for the recycling of poly(ethylene terephthalate) (PET). Model experiments on virgin material, either in the form of pellets or blow‐molded bottles, are presented. The process proposed comprises dissolution of the plastic in an appropriate solvent, reprecipitation by using a nonsolvent, thorough washing of the material obtained, and drying. The solvent mixtures involved are separated by fractional distillation for further reuse. N‐Methyl‐2‐pyrrolidone (NMP)/n‐octane + n‐hexane proved to be a particularly effective solvent/nonsolvent system. Further investigation was focused on the effect of the sample history through successive recycling cycles. The recycled material was evaluated in terms of molecular weight, crystallinity, and grain‐size analysis, resulting in an excellent quality, competing with the virgin grade. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 91–95, 2001
Thermal decomposition kinetics of an epoxy resin with rubber‐modified curing agent
Authors: Lee J. Y. , Shim M. J. , Kim S. W. 
Published: August 2002

AbstractThermal decomposition kinetics of diglycidyl ether of bisphenol A (DGEBA)/4,4′‐methylene dianiline (MDA) system with rubber‐modified MDA was studied by the methods of Ozawa, Kissinger, and Friedman, and the kinetic parameters were compared. The thermal decomposition data of the cured epoxy resin were analyzed by thermogravimetric analysis (TGA) at different heating rates. TG curves showed that the thermal decomposition of the epoxy system occurred in one stage regardless of rubber‐modified MDA content. The apparent activation energies for the DGEBA/MDA system with 10 phr of rubber‐modified MDA, as determined by the Ozawa, Kissinger, and Friedman methods, are 184, 182, and 222 kJ/mol, respectively. The thermal stability of the epoxy system increased with the increasing content of rubber‐modified MDA, which has four benzene rings with high thermal resistance due to the resonance structure. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 479–485, 2001
Impact behavior of sawdust/recycled–PP composites
Authors: Li T. Q. , Ng C. N. , Li R. K. Y. 
Published: August 2002

AbstractThe instrumented Izod and Charpy tests were performed on the sawdust–polypropylene (PP) composites to study the nature of impact resistance in the thermoplastic wood composites. The notched Izod strength was found to increase with filler content in composites containing the Maleic–anhydride–grafted PP (MAPP) additive. The Izod strength even exceeds that of the neat matrix resin at higher filler contents, indicating a methodology for applying the recycled PP and also for reinforcing the thermoplastics with wood powders. While the static tensile results show evidences for the reinforcing role of the wood filler, a fracture mechanics characterization through the Charpy impact tests effects of MAPP under the impact loading rates. The choice of MAPP as the additive was discussed accordingly for application of the sort of materials. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1420–1428, 2001
Application of isothermal and model‐free isoconversional modes in DSC measurement for the curing process of the PU system
Authors: Li Shuyan , Vuorimaa Elina , Lemmetyinen Helge 
Published: August 2002

AbstractThe dynamic, isothermal, and model‐free isoconversional modes of differential scanning calorimetry measurement were used to monitor the curing process of the polyurethane system. Conversions obtained from these three methods were in good agreement with one another, indicating that isothermal and model‐free isoconversional modes can successfully be used for monitoring the curing process. For the isothermal mode, the highest reaction rate occurred at time zero, and autoacceleration was not observed for this system. From the model‐free isoconversional mode, it was possible to calculate the activation energy changes during the curing process. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1474–1480, 2001
Modeling and simulation of urethane acrylates synthesis. II. Kinetics of uncatalyzed reaction of toluene diisocyanate with a polyether diol
Authors: Grepinet B. , Pla F. , Hobbes Ph. , Monge Th. , Swaels Ph. 
Published: August 2002

AbstractToluene diisocyanate reacts with poly(propylene glycol) during the synthesis of some urethane acrylate oligomers. The present work deals with kinetic studies and molecular characterization of the uncatalyzed bulk reaction of these two difunctional monomers. Back titration and H1‐NMR are used to follow the reaction of the different isocyanate groups with an alcohol group belonging to poly(propylene glycol) and to allow a good description of the urethane groups evolution. The global reaction rate as well as that of each individual isocyanate group are well described by a second‐order equation. Kinetic constants were calculated by using the software SIMULBATCH®. The reaction of two difunctional monomers leads to the formation of oligomers of different polymerization degrees, opposite to the reaction of TDI with a monoalcohol. Thus, another approach was developed to characterize the oligomers by size exclusion chromatography and to calculate the molecular weight distribution by using a combination of kinetic and probabilistic arguments. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3149–3160, 2001
Sorption of dye wastes by poly(vinyl alcohol)/poly(carboxymethyl cellulose) blend grafted through a radiation method
Authors: El‐Salmawi K. M. , Zaid M. M. Abu , Ibraheim S. M. , El‐Naggar A. M. , Zahran A. H. 
Published: August 2002

AbstractThe instability in water of poly(vinyl alcohol) (PVA)/poly(carboxymethyl cellulose) (CMC) was improved through radiation‐induced grafting with a styrene monomer. The PVA/CMC blend graft copolymer was used as a sorbent for dye wastes normally released from textile factories. The factors that may affect the sorption process such as time, temperature, weight of the blend graft copolymer, and volume of the dye waste were investigated. The sorption of dyestuffs by the blend graft copolymer was determined by a method based on spectroscopic analysis. The results showed that the blend graft copolymer has a high affinity for basic, acid, and reactive dyes. Meanwhile, it was observed that the sorption of dyes is more effective at the high temperature of 70oC. Moreover, it was found that the sorption of dyes depends on the weight of the blend graft copolymer and does not depend on the volume of the waste solution. The sorption of the dyestuffs by a PVA/CMC graft copolymer may be considered to be a practical method to remove organic pollutants. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 136–142, 2001
Absolute online monitoring of a stepwise polymerization reaction: Polyurethane synthesis
Authors: Çatalgil‐Giz Huceste , Giz Ahmet , Alb Alina , Reed Wayne F. 
Published: August 2002

AbstractThe feasibility of using a recently introduced method for continuous, absolute online monitoring for step‐growth polymerization was demonstrated, and polyurethane synthesis was chosen for the demonstration. The previously reported use of this method was for monitoring free‐radical initiated chain‐growth polymerization. The technique involves continuously withdrawing a small stream of reaction liquid from the polymerization reactor and pumping it through a series of light scattering and viscosity detectors. This permits the absolute weight‐average molecular weight and reduced viscosity to be simultaneously monitored as the reaction proceeds. The final weight‐average molecular weights of the polyurethane samples were compared to the separate light scattering measurements of the final products. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2070–2077, 2001
Studies on preparation and swelling properties of the N‐isopropylacrylamide/chitosan semi‐IPN and IPN hydrogels
Authors: Lee Wen‐Fu , Chen Ying‐Jou 
Published: August 2002

AbstractSemi‐interpenetrating network (semi‐IPN) polymer gels and interpenetrating network (IPN) polymer gels with thermosensitivity were prepared by introducing a biodegradable polymer, chitosan, into the N‐isopropyacrylamide (PNIPAAm) gel system. The swelling behavior, temperature sensitivity, pH sensitivity, gel strength, and drug‐release behavior of PNIPAAm/chitosan semi‐IPN and IPN hydrogels were investigated. The results indicated that the NIPAAm/chitosan semi‐IPN and IPN hydrogels exhibited pH and temperature‐sensitivity behavior and could slow drug release and diffusion from the gels. From the stress–strain curves of the hydrogels, the compression moduli of IPN gels containing crosslinked chitosan were higher than those of semi‐IPN gels. This is because IPN gels have a more compact structure. The morphology of PNIPAAm/chitosan hydrogels was also investigated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2487–2496, 2001
Polymerization of β‐pinene with ethylaluminum dichloride (C2H5AlCl2)
Authors: Guiné Raquel P. F. , Castro José A. A. M. 
Published: August 2002

AbstractThe main goal of this work is to study the cationic polymerization of terpenes, particularly of β‐pinene, with alkylaluminum catalysts. Some experiments at different polymerization temperatures (10, 20, and 50°C) were carried out with ethylaluminum dichloride catalyst, C2H5AlCl2. From the results, it is possible to draw some general conclusions about the evolution of chain growth during polymerization. This work also includes the influence of reaction temperature on some properties of the final resin, particularly the molecular weight distribution, the softening point, and the Gardner color index. The role of reducing agents, such as iodine, during the distillation of the final resin is also evaluated with respect to color and softening point. As a result of this investigation, the Mark–Howink constants for terpene resins in toluene and dicloromethane as solvents have also been experimentally determined, thus allowing a more precise use of size exclusion chromatography in the characterization of such natural based products. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2558–2565, 2001
Application of styrene‐acrylonitrile random copolymer–polyarylate block copolymer as reactive compatibilizer for polyamide and acrylonitrile‐butadiene‐styrene blends
Authors: Ohishi Hiroshi , Nishi Toshio 
Published: August 2002

AbstractStyrene‐acrylonitrile random copolymer (SAN) and polyarylate (PAr) block copolymer were applied as a reactive compatibilizer for polyamide‐6 (PA‐6)/acrylonitrile‐butadiene‐styrene (ABS) copolymer blends. The SAN–PAr block copolymer was found to be effective for compatibilization of PA‐6/ABS blends. With the addition of 3.0–5.0 wt % SAN–PAr block copolymer, the ABS‐rich phase could be reduced to a smaller size than 1.0 μm in the 70/30 and 50/50 PA‐6/ABS blends, although it was several microns in the uncompatibilized blends. As a result, for the blends compatibilized with 3–5 wt % block copolymer the impact energy absorption reached the super toughness region in the 70/30 and 50/50 PA‐6/ABS compositions. The compatibilization mechanism of PA‐6/ABS by the SAN–PAr block copolymer was investigated by tetrahydrofuran extraction of the SAN–PAr block copolymer/PA‐6 blends and the model reactions between the block copolymer and low molecular weight compounds. The results of these experiments indicated that the SAN–PAr block copolymer reacted with the PA‐6 during the melt mixing process via an in situ transreaction between the ester units in the PAr chain and the terminal amine in the PA‐6. As a result, SAN–PAr/PA‐6 block copolymers were generated during the melt mixing process. The SAN–PAr block copolymer was supposed to compatibilize the PA‐6 and ABS blend by anchoring the PAr/PA‐6 and SAN chains to the PA‐6 and ABS phases, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2300–2313, 2002
A review of marine protected areas in the northwestern Mediterranean region: siting, usage, zonation and management
Authors: Francour Patrice , Harmelin Jean‐Georges , Pollard David , Sartoretto Stéphane 
Published: August 2002

Abstract1. We present in this review a general description of marine protected areas (MPAs) in the northwestern Mediterranean and some general principles for the establishment of protected areas, including their size, location, biotope composition, regulation, and management.2. Many Mediterranean MPAs are located around or adjacent to islands, but the placement of a marine reserve close to a large urban area is not necessarily a handicap, as has been demonstrated by some examples. It is not, therefore, necessary to restrict future MPAs solely to regions of low human density.3. The conceptual question of MPA size (single large or several small — SLOSS debate) has never been explicitly considered in the selection of Mediterranenan MPAs. However, studies of fish recruitment in MPAs, and the development of a network of small MPAs between Spain and France have highlighted the importance and value of small sized MPAs (200–2000 ha).4. Whatever the location of a future MPA, its success as measured in terms of stock restoration will depend on whether (i) sufficient suitable habitat is available, (ii) the variety and abundance of prey species are adequate and (iii) the possibilities for recruitment of the biota are reasonable.5. The initial choices of zonation and legislation regulating the management of any future MPA are of primary importance. The zonation plan should be as simple as possible (gradation of 2 or 3 levels) and it should be acknowledged that the significance of management conflicts within a MPA will be inversely proportional to the extent of preliminary consultations with all of the users, both professional and amateur.6. The examples of semi‐protected areas where professional fishing is still allowed demonstrate without ambiguity the negative impact of spear‐fishing, and the limited impacts from regulated professional activities on fish assemblages. The means of regulating consist essentially of (i) a prohibition of certain type of fishing methods (trawling); and (ii) a limitation of the numbers of fishermen by a system of restriction or authorization.7. In the MPAs examined, there is a great diversity of situations in relation to the size of and distribution of duties between staff assigned to their management. However, the single most important factor underlying whether or not a MPA will be successful and beneficial is the presence of a dedicated staff. Copyright © 2001 John Wiley & Sons, Ltd.
Red coral: conservation and management of an over‐exploited Mediterranean species
Authors: Santangelo Giovanni , Abbiati Marco 
Published: August 2002

Abstract1. Corallium rubrum is a precious circum‐Mediterranean octocoral, which occurs on rocky reefs between 10 and over 250 m in depth.2. This species has been harvested for a long time and most commercial populations have been over‐exploited. The Mediterranean overall yield was reduced by 66% over the last 15 years.3. Two type populations may be identified: (a) dense shallow‐water populations consisting of small, slow‐growing, short‐lived colonies and (b) deep‐dwelling populations, composed of large, sparse, long‐lived colonies. The former populations have little economic value, but should ensure a reproductive stock for the species.4. While the structure and demography of shallow‐water populations have been studied, the demographic parameters of deep‐dwelling populations are largely unknown.5. Recent genetic studies quantified levels of genetic divergence among coastal populations. Estimated numbers of migrants among populations suggested that the planulae of C. rubrum have short‐range dispersal. Geographic distances greater than 100 km can be considered as the threshold for genetic divergence between populations.6. Development of a regime for the sustainable exploitation of this species requires a better knowledge of population dynamics, life‐history traits and quantitative genetics, especially concerning commercial populations. Copyright © 2001 John Wiley & Sons, Ltd.
Gross anatomy in the surgical curriculum in Switzerland: Improved cadaver preservation, anatomical models, and course development
Authors: Groscurth P. , Eggli P. , Kapfhammer J. , Rager G. , Hornung J.‐P. , Fasel J.D.H. 
Published: August 2002

AbstractThe invention of new techniques for surgery and interventional radiology demand improved training for ongoing specialists. The Anatomical Institutes in Switzerland support these requirements by establishing hands‐on practical training courses by using new procedures for cadaver embalming and model construction. Improvements allow courses to provide students with more realistic simulations of both established and experimental surgical methods. Through these changes, the value of in‐depth gross anatomy is enhanced as a topic of fundamental importance for the postgraduate medical and surgical curriculum. The web site http://www.unifr.ch/sgahe/snga.html contains information on courses using the Thiel embalming solution. Details about training courses in Switzerland using anatomical models are available at http://www.heartlab.org, http://www.vascular‐international.org, and http://www.elastrat.com. Anat Rec (New Anat) 265:254–256, 2001. © 2001 Wiley‐Liss, Inc.
TrkA and TrkB neurotrophin receptor immunoreactivity in the teleost (Scorpaena porcus) endocrine pancreas
Authors: Lucini Carla , Maruccio Lucianna , De Girolamo Paolo , Vega Josè A. , Castaldo Luciana 
Published: August 2002

AbstractMammalian‐like and specific neurotrophins, as well as their cognate tyrosine kinase Trk‐like receptors have been identified in teleosts. They are mainly distributed in neuronal tissues, but evidence suggests that some non‐neuronal tissues also express Trks. In this study we used immunohistochemistry to investigate the occurrence and cell distribution of Trks in the pancreas of teleosts (Scorpaena porcus). Immunoreactivity for TrkA and TrkB, but not for TrkC receptors, was found in the scorpionfish pancreas. TrkA‐like positive cells were exclusively observed within pancreatic islets, among insulin‐ and glucagon‐containing cells, but apparently did not co‐localize with these hormones. TrkB immunostaining was found in islet cells, presumably colocalized with glucagon, as well as in some cells of the exocrine portion. These data provide a morphological basis for a role of the TrkA and TrkB ligands in the endocrine pancreas of teleosts. Anat Rec 263:113–117, 2001. © 2001 Wiley‐Liss, Inc.
Immunogenicity of recombinant type IX collagen in murine collagen‐induced arthritis
Authors: Myers L. K. , Pihlajamaa T. , Brand D. D. , Cremer M. A. , Bodo M. , Ala‐Kokko L. , Kang A. H. 
Published: August 2002

AbstractObjectivePast attempts to isolate type IX collagen (CIX) from cartilage using limited proteolysis yielded partially degraded material. Recent application of recombinant technology, however, has allowed the preparation of intact native CIX. We used the murine collagen‐induced arthritis model to characterize the immunologic properties of recombinant human CIX (rCIX) produced using a baculovirus expression system.MethodsA panel of B10 congenic mice was immunized with rCIX emulsified with Freund's complete adjuvant (CFA). The ability of the rCIX to induce tolerance and suppress arthritis was determined by administration intravenously or orally before challenge with CII/CFA.ResultsNone of the mice immunized with rCIX developed overt arthritis, although 2 of 5 HLA–DR1 transgenic mice developed limited digital erythema and swelling. Recombinant CIX administered by either route effectively induced suppression of arthritis, although the suppression was less pronounced than that induced with CII. Immune responses to CIX and CII were specific, suggesting that bystander suppression, rather than cross‐reactivity with CII, was instrumental in suppressing arthritis.ConclusionThese data show that CIX down‐regulates arthritis in mice while having no associated risk of inducing arthritis.
Exchange rate uncertainty and employment: an algorithm describing ‘play’
Authors: Belke Ansgar , Göcke Matthias 
Published: August 2002

AbstractThe paper deals with the impacts of exchange rate uncertainty on the relationship between macroeconomic labour market variables. Under uncertainty, areas of weak reactions—so‐called ‘play’ areas—have to be considered at the macrolevel. The width of the play area is a positive function of the degree of uncertainty. When changes go beyond the play‐area suddenly strong reactions (‘spurts’) occur. These non‐linear dynamics are captured in a simplified linearized way. An algorithm describing linear play hysteresis is developed and implemented into a regression framework. As an empirical application, the exchange rate impacts on German employment are analysed considering play effects. Copyright © 2001 John Wiley & Sons, Ltd.