bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipid oxidation and colour in pressure‐ and heat‐treated minced chicken thighs
Authors: Beltran Elena , Pla Reyes , Capellas Marta , Yuste Josep , Mor‐Mur Montserrat 
Published: June 2004

AbstractLipid oxidation and colour in pressurised and heated chicken samples were evaluated. In a preliminary test, raw and overcooked (100 °C/60 min) minced chicken thighs were pressurised (500 MPa/50 °C/30 min). Samples were stored at 4 °C in contact with air. Thiobarbituric acid reactive substances (TBARS) were quantified at 1, 6 and 9 days. Pressure induced oxidation in chicken, but overcooking generated many more secondary oxidation compounds. In a second experiment, raw minced chicken thighs were pressurised (500 MPa/−10, 5, 20 and 50 °C/30 and 60 min) or cooked (90 °C/15 min). Samples were vacuum stored at 4 °C. TBARS were measured at 1 and 9 days, whereas colour parameters (L, a, b and ΔE) were determined at 1 day. No differences in TBARS values were observed between untreated and pressurised samples, whereas cooked samples presented the highest values. Pressurisation for 30 and 60 min generated similar TBARS contents. At 9 days, oxidation values did not increase. Pressurisation and cooking induced marked colour changes. Pressurised samples were lighter and less red than untreated ones. Samples pressurised at 50 °C were the palest and, together with cooked samples, presented the lowest a values. Therefore pressurised chicken thigh cannot be marketed as a fresh product but can be incorporated as an ingredient in ready‐to‐eat meals. Copyright © 2004 Society of Chemical Industry
Cover Picture: Macromol. Chem. Phys. 9/2004
Authors: Tohi Yasushi , Nakano Takashi , Makio Haruyuki , Matsui Shigekazu , Fujita Terunori , Yamaguchi Tsutomu 
Published: June 2004

Cover: The cover shows the unique polymerization behavior of FI Catalysts, which is the production of well‐defined uni‐ and bimodal polyethylenes. This polymerization behavior stems from the fact that FI Catalysts can possess more than one catalytically active species arising from the coordination modes of two non‐symmetric ligands. The FI catalysis represents a notable example of the formation of bimodal polymers by a single precatalyst in a single‐stage polymerization process.Further details can be found in the Full Paper by Y. Tohi, T. Nakano, H. Makio, S. Matsui, T. Fujita* and T. Yamaguchi on page 1179.
Thermal Stability of Gamma Irradiated Low Density Polyethylene Films Containing Hindered Amine Stabilizers
Authors: Zaharescu Traian , Kaci Mustapha , Hebal Ghania , Setnescu Radu , Setnescu Tanta , Khima Rochedine , Remili Chérifa , Jipa Silviu 
Published: June 2004

AbstractSummary: The thermal stability of gamma irradiated low density polyethylene (LDPE) films in presence of various structures of hindered amine stabilizers (HAS) was investigated by the oxygen uptake method under constant temperature of 180 °C and normal pressure conditions. The thermo‐oxidation was run using air environment. The sigmoidal dependency of oxygen uptake allows the calculation of the main kinetic parameters: oxidation induction time and oxidation rate on the propagation step. The various steps involved in the thermal degradation process were detected by the derivative procedure applied to the dependencies of oxygen uptake on time. It was found that the kinetic parameters of the thermal degradation process, determined by oxygen uptake, revealed the antioxidant role of HAS in γ‐irradiated LDPE films by providing better stability, when compared with the unstabilized samples. Moreover, the results indicated that the dependencies of oxygen uptake on thermal degradation time involved two degradation stages: the former occurring in the ungrafted moiety and the latter taking place after the antioxidant depletion is achieved. The stabilization efficiency of these oxidation inhibitors provides satisfactory thermal resistance to LDPE films, especially those based on an alkoxyamine structure.Dependencies of oxygen uptake on time at the thermal degradation of LDPE irradiated at 812 kGy. (‐□‐) free of additive; (‐○‐) Tinuvin 123; (‐▵‐) Sanduvor PR 31; (‐⋄‐) Uvasil 299.magnified imageDependencies of oxygen uptake on time at the thermal degradation of LDPE irradiated at 812 kGy. (‐□‐) free of additive; (‐○‐) Tinuvin 123; (‐▵‐) Sanduvor PR 31; (‐⋄‐) Uvasil 299.
Reactive Compatibilizer Precursors for LDPE/PA6 Blends, 4
Authors: Filippi Sara , Yordanov Hristo , Minkova Liliya , Polacco Giovanni , Talarico Marco 
Published: June 2004

AbstractSummary: The effectiveness of some thermoplastic elastomers grafted with maleic anhydride (MA) or with glycidyl methacrylate (GMA) as compatibilizer precursors (CPs) for blends of low density polyethylene (LDPE) with polyamide‐6 (PA) has been studied. The CPs were produced by grafting different amounts of MA or GMA onto a styrene‐block‐(ethylene‐co‐1‐butene)‐block‐styrene copolymer (SEBS) (KRATON G 1652), either in the melt or in solution. A commercially available SEBS‐g‐MA copolymer with 1.7 wt.‐% MA (KRATON FG 1901X) was also used. The effect of the MA concentration and of other characteristics of the SEBS‐g‐MA CPs was also studied. The specific interactions between the CPs and the blends components were investigated through characterizations of the binary LDPE/CP and PA/CP blends, in the whole composition range. It was demonstrated that the SEBS‐g‐GMA copolymers display poor compatibilizing effectiveness due to cross‐linking resulting from reactions of the epoxy rings of these CPs with both the amine and the carboxyl end groups of PA. On the contrary, the compatibilizing efficiency of the MA‐grafted elastomers, as revealed by the thermal properties and the morphology of the compatibilized blends, was shown to be excellent. The results of this study confirm that the anhydride functional groups possess considerably higher efficiency, for the reactive compatibilization of LDPE/PA blends, than those of the ethylene‐acrylic acid and ethylene‐glycidyl methacrylate copolymers investigated in previous works.SEM micrograph of the 75/25 LD08/PA blend (with 2 phr SEBSMA1).magnified imageSEM micrograph of the 75/25 LD08/PA blend (with 2 phr SEBSMA1).
Elaboration of Poly(ε‐caprolactone)‐g‐TiNbO5 Nanocomposites via in situ Metal Complex Initiated Intercalative Polymerization
Authors: Bruzaud Stéphane , Carpentier Jean‐François , Grohens Yves 
Published: June 2004

AbstractSummary: The preparation of poly(ε‐caprolactone)‐g‐TiNbO5 nanocomposites via in situ intercalative polymerization of ε‐caprolactone initiated by an aluminium complex is described. These nanocomposites were obtained in the presence of HTiNbO5 mineral pre‐treated by AlMe3, but non‐modified by tetraalkylammonium cations. These hybrid materials obtained have been characterized by Fourier transform infrared absorption spectroscopy, wide‐angle X‐ray scattering, scanning electron microscopy, and dynamic mechanical analysis. Layered structure delamination and homogeneous distribution of mineral lamellae in the poly(ε‐caprolactone) (PCL) is figured out and strong improvement of the mechanical properties achieved. The storage modulus of the nanocomposites is enhanced as compared to pure PCL and increases monotonously with the amount of the filler in the range 3 to 10 wt.‐%.SEM image of the fractured surface of a PCL‐TiNbO5 nanocomposite film.magnified imageSEM image of the fractured surface of a PCL‐TiNbO5 nanocomposite film.
Structural and Mechanical Properties Changes of Ethylene‐α‐olefin Copolymer Blends Induced by Thermal Treatments and Composition
Authors: Chen Fei , Shanks Robert A. , Amarasinghe Gandara 
Published: June 2004

AbstractSummary:Blends of single‐site catalysed ethylene‐α‐butene (C4VLDPE) and ethylene‐α‐octene (C8VLDPE) copolymers were prepared by melt extrusion. The phase morphology, thermal and mechanical properties of the blends have been investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), tensile test and dynamic mechanical analysis (DMA). Depending on the composition and thermal history, significant differences in structure and behaviour were found. It was also found that some degree of co‐crystallization occurred for quenched blends; whereas most of the oven slowly cooled blends showed two well‐defined melting peaks, indicating that the slow cooling favoured partial segregation of the fractions with different degrees of branching to form two morphologies. Moreover, SEM revealed morphology of the thinner crystals distributed in‐between the thicker sheaf‐like crystals for the slowly cooled blends with 20–50% C8VLDPE. Therefore, the synergism in mechanical properties for the blends with 20–50% C8VLDPE is due to a combination of larger crystal size, more complete phase separation and interfacial interaction produced by the segregation effect of the slow cooling treatment. DMA studies showed that the storage modulus increased as the addition of C8VLDPE and modulus for the slowly cooled blends are about twice those measured for the quenched ones, indicating higher stiffness of the blends. The smooth shift ofβrelaxation temperature with addition of C8VLDPE for both sets of blends confirmed the miscibility in the amorphous phase.SEM image of the C4VLDPE‐C8VLDPE (50/50) blend after oven slow cooling treatment.magnified imageSEM image of the C4VLDPE‐C8VLDPE (50/50) blend after oven slow cooling treatment.
Methionine‐Containing Poly(amino acid) Hybrid Fibers via Self‐Assembly at Aqueous Interface
Authors: Satoyoshi Daijiro , Hachisu Masakazu , Amaike Masato , Ohkawa Kousaku , Yamamoto Hiroyuki 
Published: June 2004

AbstractSummary: Using sulfonium groups to create a novel fiber material, methionine‐containing hybrid fibers were prepared from S‐methylated poly(L‐methionine) and poly(L‐lysine, L‐methionine) solutions with gellan solution by polyion complex (PIC) formation via self‐assembly at the aqueous interface. The breaking strain of the PIC fibers were increased by incorporation of methionine residues into the poly(L‐lysine). These findings may provide a new approach for preparing a wool‐like fiber in aqueous media using the synthetic water‐soluble methionine‐containing poly(amino acid)s.SEM image of Met‐containing PIC fiber: (a) poly[Met19Met(SMe)81]‐gellan fiber (magnification, ×500).magnified imageSEM image of Met‐containing PIC fiber: (a) poly[Met19Met(SMe)81]‐gellan fiber (magnification, ×500).
Recent Advances for Intumescent Polymers
Authors: Bourbigot Serge , Le Bras Michel , Duquesne Sophie , Rochery Maryline 
Published: June 2004

AbstractSummary: This paper reviews recent approaches for making intumescent systems. The mechanisms of action involving intumescence are described and commented on. Synergistic aspects using zeolites and organoclays are also considered and discussed. New strategies are examined on the basis of the mechanism of intumescence. The approach of using char forming polymers as additives (blend technology) is also fully discussed. This consists of substituting classical polyols (char forming agents) with char forming polymers (polyamides and thermoplastic polyurethane). It will be shown that the advantages of this concept are to obtain flame‐retarded (FR) polymer blends with improved mechanical properties in comparison with polymers loaded with classical formulations, and the avoidance of problems due to the water solubility of the polyols and their migration. The “nanocomposite approach” enhances the performance of intumescent systems by using a nanostructured char forming polymer. It will be shown that this combination of intumescence via the blending approach and nanocomposites enhances both flame retardancy and mechanical properties, and allows many specifications to be produced (for example, the design of EVA‐based materials for flame retarded low voltage cables and wire). This appears to be one of the most promising ways for designing new efficient intumescent materials.Intumescent residue after LOI test of an intumescent poly(propylene).magnified imageIntumescent residue after LOI test of an intumescent poly(propylene).
Effects of Temperature and Surfactants on the Equilibrium Swelling Behavior of Poly[acrylamide‐co‐(itaconic acid)] Hydrogels
Authors: Çaykara Tuncer , Doğmuş Melike 
Published: June 2004

AbstractSummary: The swelling equilibrium of poly(acrylamide) [PAAm] and poly[acrylamide‐co‐(itaconic acid)] [P(AAm/IA)] hydrogels was studied as a function of temperature and IA content in aqueous solutions of surfactants: sodium dodecyl sulfate (SDS, anionic) and hexadecyltrimethylammonium bromide (HTAB, cationic). P(AAm/IA) hydrogels in water exhibited reentrant conformational transitions depending on temperature, whereas PAAm hydrogels were not affected with the change of temperature. The equilibrium‐volume‐swelling ratio of P(AAm/IA) hydrogels increased sharply in SDS solutions, with an increase of the mole percent of IA. However, in HTAB solution, the equilibrium‐volume‐swelling ratio of these hydrogels decreased with an increase of IA content.The equilibrium volume‐swelling ratios of the hydrogels in water shown as a function of temperature.magnified imageThe equilibrium volume‐swelling ratios of the hydrogels in water shown as a function of temperature.
Novel Hyperbranched Poly([1,2,3]‐triazole)s Derived from AB2 Monomers by a 1,3‐Dipolar Cycloaddition
Authors: Scheel Arnulf J. , Komber Hartmut , Voit Brigitte I. 
Published: June 2004

AbstractSummary: Novel hyperbranched poly([1,2,3]‐triazole)s were synthesized from several AB2 monomers by a 1,3‐dipolar cycloaddition reaction. The compound 3,5‐bis(propargyloxy)benzyl azide was polymerized thermally at room temperature leading to 1,4‐ and 1,5‐disubstituted poly([1,2,3]‐triazole) and catalytically leading only to the 1,4‐disubstituted poly([1,2,3]‐triazole). Only the thermal reaction led to fully soluble products. The AB2 monomers containing an internal alkyne A unit could be autopolymerized thermally under mild reaction conditions leading to soluble, high‐molecular‐weight hyperbranched poly([1,2,3] triazole)s. All products were characterized by detailed NMR investigations.Synthesis route for polymers 8a and 8b.imageSynthesis route for polymers 8a and 8b.
Self‐Assembly of Poly(γ‐benzyl L‐glutamate)‐graft‐Poly(ethylene glycol) and Its Mixtures with Poly(γ‐benzyl L‐glutamate) Homopolymer
Authors: Tang Dongmei , Lin Jiaping , Lin Shaoliang , Zhang Suning , Chen Tao , Tian Xiaohui 
Published: June 2004

AbstractSummary: Self‐association behaviors of poly(γ‐benzyl L‐glutamate)‐graft‐poly(ethylene glycol) (PBLG‐graft‐PEG) and its mixtures with PBLG homopolymer in aqueous media were investigated by fluorescence spectroscopy, transmission electron microscopy (TEM), and nuclear magnetic resonance (NMR) spectroscopy. It was revealed that PBLG‐graft‐PEG could self‐assemble to form polymeric micelles with a core‐shell structure in the shape of spindle. The introduction of PBLG homopolymer not only decreases the critical micelle concentration, but also changes the morphology of the micelles.The excitation fluorescence spectra of pyrene as a function of concentrations for the mixture of PBLG‐graft‐PEG with PBLG and a TEM image of the formed micelles.imageThe excitation fluorescence spectra of pyrene as a function of concentrations for the mixture of PBLG‐graft‐PEG with PBLG and a TEM image of the formed micelles.
Polysilane‐Cycloimmonium Salts: New Materials for Organic Semiconductors
Authors: Ardeleanu Rodinel , Mangalagiu Ionel , Sacarescu Gabriela , Simionescu Mihaela , Sacarescu Liviu 
Published: June 2004

AbstractSummary: This work presents the first synthesis of a new polymer obtained by catalytic addition of the SiH groups of a poly[methyl(H)silane‐co‐methylphenylsilane] backbone to an N‐(allyl)cycloimmonium salt. This hybrid polymer was characterized by spectroscopic analysis, thermogravimetric analysis and gel‐permeation chromatography (GPC). The pendant N‐(allyl)cycloimmonium segments lead to the formation of molecular dipoles, as evidenced by electrical polarization experiments.Structure of the polysilane‐cycloimmonium salt.imageStructure of the polysilane‐cycloimmonium salt.
End‐Group Characterization of Poly(acrylic acid) Prepared by Nitroxide‐Mediated Controlled Free‐Radical Polymerization
Authors: Lefay Catherine , Belleney Joël , Charleux Bernadette , Guerret Olivier , Magnet Stéphanie 
Published: June 2004

AbstractSummary: A low‐molar‐mass poly(acrylic acid) with a narrow molar‐mass distribution, prepared by SG1 nitroxide‐mediated controlled free‐radical polymerization, was subjected to end‐group analysis to confirm its living nature. 1H and 31P NMR spectroscopy confirmed the presence of the SG1‐based alkoxyamine end group. Furthermore, chain extension with styrene and n‐butyl acrylate demonstrated the ability of the homopolymer to initiate the polymerization of a second block. These results open the door to the synthesis of poly(acrylic acid)‐based block copolymers by direct nitroxide‐mediated polymerization of acrylic acid.Acrylic acid polymerization using an alkoxyamine initiator based on SG1 (N‐tert‐butyl‐N‐(1‐diethyl phosphono‐2,2‐dimethylpropyl) nitroxide resulting in a homopolymer capable of initiating the polymerization of a second block.imageAcrylic acid polymerization using an alkoxyamine initiator based on SG1 (N‐tert‐butyl‐N‐(1‐diethyl phosphono‐2,2‐dimethylpropyl) nitroxide resulting in a homopolymer capable of initiating the polymerization of a second block.
Partially Sulfonated Polystyrene and Poly(2,6‐dimethyl‐1,4‐phenylene oxide) Blend Membranes for Fuel Cells
Authors: Kim Bokyung , Jung Bumsuk 
Published: June 2004

AbstractSummary: Based on Flory–Huggins parameters (χ), the miscibility and the effect of morphological change on proton conductivity and methanol permeability of partially sulfonated polystyrene (SPS) and partially sulfonated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (SPPO), having an identical ion exchange capacity, were investigated. When 50 wt.‐% of SPPO was blended, both the proton conductivity and methanol permeability had the highest values, which resulted from the change of amorphous domains and the hydrogen bonding between the two ionomers.The proton conductivities, water uptake and methanol permeability for the SPPO/SPS blend membranes studied here. The membranes with 50 wt.‐% SPPO clearly showed the greatest increase in these properties.imageThe proton conductivities, water uptake and methanol permeability for the SPPO/SPS blend membranes studied here. The membranes with 50 wt.‐% SPPO clearly showed the greatest increase in these properties.
Monomode Microwave‐Assisted Atom Transfer Radical Polymerization
Authors: Zhang Huiqi , Schubert Ulrich S. 
Published: June 2004

AbstractSummary: The first monomode microwave‐assisted atom transfer radical polymerization (ATRP) is reported. The ATRP of methyl methacrylate was successfully performed with microwave heating, which was well controlled and provided almost the same results as experiments with conventional heating, demonstrating the absence of any “microwave effect” in ATRP (in contrast to several literature reports). Furthermore, we found that the main advantage of the microwave‐assisted reactions over conventional reactions, i.e., a significant increase of reaction rates, only had its limited application in ATRP, even in very slow ATRP systems with high targeted molecular weights.Comparison of the kinetic plots of the ATRP of MMA ([MMA]0/[EBIB]0/[CuCl]0/[NHPMI]0 = 200:1:1:3, MMA/DMF = 1:1 v/v) carried out at 90 °C in DMF with microwave (▴) and conventional heating (•), respectively.imageComparison of the kinetic plots of the ATRP of MMA ([MMA]0/[EBIB]0/[CuCl]0/[NHPMI]0 = 200:1:1:3, MMA/DMF = 1:1 v/v) carried out at 90 °C in DMF with microwave (▴) and conventional heating (•), respectively.
Novel Approach to Fabricate Carbon Molecular‐Sieve Membranes Based on Consideration of Interpenetrating Networks
Authors: Tin Pei Shi , Chung Tai‐Shung 
Published: June 2004

AbstractSummary: Carbon molecular‐sieve membranes (CMSMs) have shown great potential for gas separation. They exhibit high selectivity by permitting effective size‐ and shape‐separation between gas molecules of similar molecular dimensions. Hence, the control of their pore size is very important. While previous studies have focused on the conditions of pyrolysis and its effect on CMSM properties, a novel approach is reported here whereby the precursor polymer is chemically modified prior to pyrolysis and the resultant CMSM was investigated for its gas separation properties. Pyrolysis of chemically crosslinked and uncrosslinked Matrimid® resulted in a change in d‐spacing from 5.6 to 3.6 and 3.7 Å, respectively. The crosslinked CMSM also exhibited greater ordering in its packing. The Matrimid‐derived CMSMs exhibited excellent separation properties for CO2/CH4.Mechanism of chemical crosslinking modification.imageMechanism of chemical crosslinking modification.
Cover Picture: Macromol. Rapid Commun. 12/2004
Authors: Michishita Takeshi , Takashima Yoshinori , Harada Akira 
Published: June 2004

Cover: Polyisoprenes were found to form inclusion complexes with cyclodextrins with high selectivity to give crystalline compounds. β‐Cyclodextrin formed complexes only with polyisoprene of low molecular weight. γ‐Cyclodextrin formed complexes with polyisoprenes of high molecular weight. α‐Cyclodextrin did not form complexes with polyisoprene of any molecular weight.Further details can be found in the Communication by T. Michishita, Y. Takashima, and A. Harada* on page 1159.
Consumer rationality and credit card pricing: An explanation based on the option value of credit lines
Authors: Park Sangkyun 
Published: June 2004

AbstractAn option is embedded in credit cards. Since credit cards offer open credit lines, cardholders can borrow at the same terms when they become riskier. This option value raises the zero‐profit card rate. Furthermore, adverse selection occurs if cardholders are better informed about the probability of becoming riskier in the future and borrow more when they become riskier. The adverse selection can limit rate competition and keep the card rate above the zero‐profit card rate. An up‐front fee is not a good alternative because it is also vulnerable to adverse selection. A low introductory card rate is an effective way to avoid the adverse selection problem when asymmetric information is mainly about the change in the borrower's risk profile in the future, as opposed to the riskiness in the present period. Copyright © 2004 John Wiley & Sons, Ltd.
Residual income claimancy, monitoring, and the R&D firm: Theory with application to biotechs
Authors: Chang Koyin , Garen John 
Published: June 2004

AbstractThis paper models the assignment of residual income claimancy to an R&D manager and applies the model to biotechnology firms. Residual income claimancy provides incentives for the manager to monitor the R&D process. Since the nature of R&D and of monitoring scientific effort is different, our model predicts stark differences in the residual income claimancy of managers and in other aspects of organization for innovative R&D firms like biotechs. In particular, R&D firms are expected to be more owner‐managed, more expert‐managed, and smaller in size. Cross‐sectional data on biotechnology firms is consistent with these implications. Additionally, longitudinal data indicate that as firms alter their focus on biotech research, their organizational structure changes as expected. Our approach suggests a process of firm and industry evolution related to technological maturity and points to the importance of incentives rather than risk sharing in determining organizational form, similar to the original analysis of franchising. Copyright © 2004 John Wiley & Sons, Ltd.