bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recycling of polymers used in aerospace industry. Treatment by plasma process
Authors: Crouzillat G. , Saul H. , Hognat J. , Costes B. 
Published: March 2011

AbstractAEROSPATIALE has, for more than 20 years, developed and perfected a device intended to simulate the atmospheric re‐entry conditions: the plasma torch. This technology, developed for the needs of space industry, is also applicable in other industrial fields like metallurgy or waste disposal.For most residues, as, for instance, for polymer residues (in particular for composite materials), incineration is the best solution to be considered. Although the organic molecule may be a real danger for man and his environment, it is possible to split it into elementary molecules easy to eliminate without risks by the simultaneous application of heat and a specific chemical environment.The use of additives in the polymers makes it necessary in most cases to use temperatures as high as possible; these high temperatures have the additional advantage of preventing harmful recombinations in the reaction chamber. Only plasma processes give the possibility to ensure high temperatures in large capacity chambers in a controlled atmosphere.
Re‐use of chlorine‐containing polymers
Authors: Braun D. 
Published: March 2011

AbstractPoly(vinyl chloride) (PVC) and some other chlorine‐containing polymers belong to one of the most widely applied groups of thermoplastics. Their main disadvantage is the rather limited thermal stability, which requires the addition of heat stabilizers to prevent dehydrochlorination and discolouration. Hydrogen chloride is also the main volatile decomposition product during combustion of PVC; therefore, PVC‐waste is less suited for the so‐called thermal recycling. For the re‐use of PVC and similar polymers it is necessary to characterize these products by molecular weight (or at least viscometry), internal double bonds and other defect structures, stability against the influence of heat (and in some cases of light) and a few other properties. The application of these methods for deciding about the re‐usability of PVC roofing sheets and for the injection moulding of PVC scrap is demonstrated.
Biological recycling of plastics containing ester bonds
Authors: Tokiwa Yutaka , Iwamoto Akira , Koyama Masatoshi , Kataoka Naoaki , Nishida Haruo 
Published: March 2011

AbstractBiodegradable blend plastics such as polycaprolactone (PCL)‐conventional plastics blends, PCL‐polystyrene blend foams, PCL‐poly‐3‐hydroxybutyrate (PHB) blends, PCL‐raw cornstarch (CS) blends and PCL‐CaCO3 blends were developed. It was suggested that the thermophilic composting of biodegradable plastics containing PCL was one of powerful technologies for recycling of biodegradable plastics. Furthermore, we tried to get useful products from biodegradable plastics by microbial fermentation processes. Polypropylene (PP)‐CS blend and PCL‐CS blend plastics were aerobically converted into ethanol by Bacillus polymyxa. PHB and PP‐CS blend and PCL‐CS blend plastics were anaerobically converted into some organic acids and methane gas by mixed microbial cultures with a methanogenic bacterium.
Secondary poly(propylene) from used accumulators reused as raw material
Authors: Staicu Doina , Ciupitoiu A. , Stefan Doina , Gagui C. , Constantinescu Elena , Fragu O. 
Published: March 2011

AbstractA reuse process, as raw material, of secondary poly(propylene) from used accumulators, is presented. The importance of solving the scientific aspects, concerning the influence of residual impurities and those resulted from ageing, on properties of regenerated polymers, in certifying the reliability of reusing the secondary polymers as a raw material, is underlined.
Capability and limitations of polymer recycling from electrical appliances and re‐use for high quality applications
Authors: Wartusch Johann 
Published: March 2011

AbstractLarge quantities of thermoplastic engineering plastics are used in the manufacture of electrical household appliances. The prevailing environmental situation necessitates an investigation of their reutilization after service life. In order to increase the chances of this re‐applicability, a high level of product quality has to be strived for. Different thermoplastics were investigated, but ‐ regarding its application in washing machine water tanks ‐ in more detail PP and its recyclability after the aggravating conditions of long‐term attack of boiling detergent. It was found that recycled mono‐PP has good chances for re‐use, if it is adequately stabilized either initially or sub‐sequently.
The issue of contamination in recycling
Authors: Hope P. S. , Parsons D.A.G. , Capaccio G. , Kitchiner M. J. 
Published: March 2011

AbstractThis paper describes a model study aimed at establishing the main contamination issues for material recycling of HDPE blow‐moulded containers. Detergent, bleach, lubricating oil and white spirit containers purchased from retailers have been recycled separately. Both atmospheric contamination during recycling, and the presence of contaminants in the recycled pellets and containers, have been measured. Standard washing and extrusion procedures were used with no attempt to optimise the treatment at this stage. The main contaminants found in the recycled bottles were oil and white spirit (both up to 0.6% by weight). Small amounts of chlorine (from bleach), limonene (from detergent) and oil additives were also found in the reprocessed pellet.
Thermodynamics of phase equilibria and critical phenomena of quasi‐binary systems of multicomponent polymers 1 and 2 and of quasi‐ternary systems consisting of multicomponent polymers 1 and 2 in a single solvent
Authors: Kamide Kenji 
Published: March 2011

AbstractAs an extension of our previous work, attempts were made to establish fundamental relations giving the spinodal curve (SC), the critical solution point (CSP), the cloud point curve (CPC) and the shadow curve for quasi‐binary systems of multicomponent polymers 1 and 2 (P1/P2) and quasi‐ternary systems consisting of multicomponent polymers 1 and 2 in a single solvent (P1/P2/S). The procedure of computer experiment based on the above fundamental equations derived was also attempted to be established. The systematic computer experiments were carried out to examine the effects of the molecular characteristics of polymers and the mutual interaction parameter on the phase diagram.
Structure formation in polymer blend solutions
Authors: Kammer H. W. , Kummerlöwe C. , Morgenstern B. 
Published: March 2011

AbstractDevelopment of phase‐separated morphologies has been studied in polymer blend solutions and forced mixtures of highly immiscible polymers by optical microscopy, DSC and light scattering. Unmixing was induced by different courses of solvent evaporation and by thermal agitation, respectively. Blends comprising different kinds of flexible and rigid chain molecules display various phase patterns in the late stage of phase decomposition which can be characterized roughly as being either regularly bicontinuous or irregularly shaped. Effects of polymer‐polymer interaction and the blending ratio are discussed. Generally, evolution of morphologies depends on both internal parameters of the system and externally imposed unmixing conditions. Limits of percolating morphologies in the course of phase separation can be established qualitatively.
Solution properties of poly(thiocarbonates)
Authors: Hernández‐Fuentes Irmina 
Published: March 2011

AbstractFor a series of poly(thiocarbonates) derived from bisphenol A several conformational and thermodynamic solution properties (partial specific volume, refractive index increment, effective dipole moment and characteristic ratio) were summarized. The effect of the structure, size and polarity of the different poly(thiocarbonates) side chains on these properties were analyzed. The high rotational freedom of the poly(thiocarbonate) chains, obtained from theoretical calculations, justifies the variation of the different properties experimentally obtained in the studied polymers.
Formation of polymer ‐ polymer complexes in the system poly(methacrylic acid) ‐ hydroxyethylcellulose
Authors: Lath Dieter , Šivová Mária 
Published: March 2011

AbstractAn interpolymer complex was prepared by mixing aqueous solutions of poly(methacrylic acid) and hydroxyethylcellulose (molar substitution 2.5) and studied by using viscometric method. The hydrogen bonding is primarily involved in these complexations, but the hydrophobic interaction plays also an important role. The complex composition is not changing with the solvents used and is stable in the temperature range 25 °C ‐ 65 °C.
Investigation on micelle forming behavior of poly(styrene‐isoprene) diblock copolymers in selective solvents via size exclusion chromatography
Authors: Lujia Pu , Guoxiong Yuan , Bilin Li , Zhongde Xu 
Published: March 2011

AbstractSize Exclusion Chromatography(SEC) was used to investigate the micelle forming behavior of Poly(styreneisoprene) diblock copolymers, with same composition and various molecular weight in different selective solvents at different temperatures. The aggregation number and aggregation energy of micelle can be determined. The effects of selective solvent, temperature and molecular weight of PS‐PI on micelle forming behavior have been discussed.
Time‐resolved fluorescence and light scattering studies of water‐soluble block‐copolymer micelles with polyelectrolyte shells
Authors: Procházka K. , Kiserow D. , Ramireddy C. , Webber S. E. , Munk P. , Tuzar Z. 
Published: March 2011

AbstractFluorescently‐tagged diblock polystyrene‐block‐poly(methacrylic acid) copolymers were prepared by anionic polymerization and subsequent hydrolysis. The copolymers dissolve in 1, 4‐dioxane‐rich/water solvents and form micelles which may be transferred into water and buffers by a stepwise dialysis. Fluorescence techniques and quasielastic light scattering (QELS) were used to study the properties of those micelles.
Functionalized polymers I. Poly(dichloroalkyl itaconates), synthesis and solution properties
Authors: Radíc Deodato , Dañin Claudia , Opazo Alejandra , Gargello Ligia 
Published: March 2011

AbstractThe synthesis of poly(di‐2‐chloroethyl itaconate) (PD2CEI) and poly(di‐3‐chloropropyl itaconate) (PD3CPI) was carried out. The dilute solution behaviour of these polymers in tetrahydrofuran and chloroform at 298 K has been studied, by viscometry, membrane osmometry, and size‐exclusion chromatography (SEC) measurements. The Kuhn‐Mark‐Houwink‐Sakurada relationships were established. The flexibility factors σ and C∞ and the thermodynamic parameters B were calculated using the Stockmayer‐Fixman equation. The results obtained are compared with those found for the corresponding poly(methacrylates) and the poly(dialkyl itaconates), and discussed in terms of specific influence of the chlorine incorporated in the side chain.
Quasi‐chemical approximation for nonrandomness in the hole theory of polymeric systems: Application to homopolymer/random copolymer blends
Authors: Xie Hankun , Nies Erík 
Published: March 2011

AbstractThe non‐random‐mixing version of the Holey‐Huggins theory is used to extract molecular parameters from the experimental equation of state data of polystyrene, poly(p‐bromostyrene) and a random copolymer poly(styrene‐co‐p‐bromostyrene) of known composition. With these parameters upper critical miscibility behavior, in qualitative agreement with experimental observations, is predicted for the system poly(styrene‐co‐p‐bromostyrene)/polystyrene. Quantitative agreement can be obtained for the equation of state and miscibility behavior if small changes in the values of the cross parameters are allowed.
Polymeric porphyrins as new photocatalysts in photodynamic therapy of cancer
Authors: Wöhrle D. , Ardeshirpur A. , Heuermann A. , Müller S. , Graschew G. , Rinneberg H. , Kohl M. , Neukammer J. 
Published: March 2011

AbstractPhotodynamic therapy and diagnosis (PDT) is described as an efficient clinical method for the treatment of cancer patients using hematoporphyrin derivative (Hpd) as sensitizer. Newly developed metal‐containing porphyrin type compounds are potential agents for PDT. A concept for covalently bound polymeric metal‐containing or metal‐free sensitizers is discussed. First results of these polymeric sensitizers are reported from in vivo experiments. High tumor accumulation up to 30% was observed. Results of fluorescence diagnosis are shown.
Applications of highly luminescent transition metal complexes in polymer systems
Authors: Demas J. N. , Degraff B. A. 
Published: March 2011

AbstractAdvances in understanding the photophysics and photochemistry of transition metal complexes offer opportunities to utilize these materials as luminescence sensors and probes. However, heterogeneity has an enormous effect on luminescence, quenching, and photochemistry. An intimate understanding of the detailed interactions between the complexes and their environment will be necessary before the rational design of new high performance sensors and probes can be achieved. Such understanding is fairly well established for homogeneous media, but it is still in its infancy in solid supports (surfaces and polymers). We present case studies involving luminescent metal complexes bound to a variety of polymer systems. Both their potential and the difficulties inherent in these composite systems are presented. We discuss tools that have proved useful or are likely to be valuable in unraveling these complex systems.
Oxidative phenol coupling catalyzed by polymer‐bound copper‐imidazole complexes
Authors: Challa G. , Chen W. , Reedijk J. 
Published: March 2011

AbstractPolymer‐bound imidazole‐copper(II) complexes were investigated and applied as catalysts for oxidative coupling (polymerization) of 2,6‐dialkylphenols. These polymeric catalysts were also immobilized on silica particles through adsorption, quaternization and grafting. Especially, the grafted catalysts showed interesting catalytic properties, e.g. good specificity for C‐O coupling and very good stability during prolonged use in continuous processes. This stability furnished new information about the mechanism of the oxidative coupling polymerization. Finally, this reaction was optimized for the preparation of PPO‐type telechelics.
Hydrogenation catalytic behaviors of palladium complexes of chitin and chitosan
Authors: Wang Xin‐Xin , Huang Mei‐Yu , Jiang Ying‐Yan 
Published: March 2011

AbstractPalladium complexes of chitin and chitosan have been shown to have catalytic activities for hydrogenation at room temperature and under atmospheric pressure. They could catalyze not only reduction of olefines but also aromatic nitro‐compounds and acrylic acid. And they are very active, stable and selective. They also show different catalytic behaviors in different pH solutions. It is noteworthy that the catalytic activities of the two polymer‐supported metal complexes in the cycle of pH 11 → pH 2 → pH 11 are reversible.
Syntheses of organometallic monomers containing cobalt and manganese
Authors: Miller Edward J. , Naughton Micheal J. , Weigelt Carolyn A. , Bradt Jean E. , Serth Judy A. , Ofslager Christian L. , O'Brien William J. 
Published: March 2011

AbstractDirect electrophilic substitution of the cyclopentadienyl ring of cymantrene has been used to prepare five cymantrenyl‐monomers with unsaturated sidechains. Direct substitution of cymantrene with acryloyl‐ and methacryloyl chloride under Friedel‐Crafts conditions has led to acryloyl‐ and methacryloylcymantrene. The complexes have been characterized using 1H and 13C NMR, IR and elemental analysis. Both complexes polymerize under treatment with AIBN at 60–70°C. The chelated complex [n5‐C5H4(CH2CH=CH2)]‐Co[(NH)2C6H4], was prepared from the treatment of [n5‐C5H4(CH2CH=CH2)]Co(CO)2 with I2 followed by (NH)2C6H4 and base. The complex was characterized with 1H NMR and IR but failed to undergo free‐radical polymerization. The strategies used to prepare organometallic polymers are discussed.
Coordination properties of polymeric azacrown ethers
Authors: S. Psheshetsky V. , Lishinsky V. L. , Kokorin A. I. , Tsarkova L. A. , Rakhnianskaja A. A. , Pertsov N. V. 
Published: March 2011

AbstractNew polymeric aza‐crown ethers (PACE), soluble in water and organic solutions and cross‐linked ones, containing different macrocycles in side chains have been synthesised by polymerisation and chemical modification reactions. The coordination próperties of these PACE are studied. It is shown that during coordination of the VO2+, Cu2+ ions with PACE, cross‐linking of macromolecules by metal ions takes place by “sandwich” complex formation. The character of complexes distribution along PACE coils may be equal or nonequal, depending on polymer reactivity. The synthesised PACE are used as high specific polymer reagents for colloid rare metals recovery. It is shown that flocculation of negatively charged inorganic sols with PACE is due to electrostatic adsorption and specific binding. In acid and neutral media, dispersions of gold, silver, copper ferrocyanide and silicon dioxide undergo high flocculation as a result of non‐specific electrostatic adsorption. Alkaline media provide conditions for donor‐acceptor binding, increasing flocculation selectivity. In the uncharged state (pH 11,2) PACE exhibit high selectivity in binding gold particles. Stability of colloidal dispersions in the presence of monomer aza‐crown ether (ACE) indicates an important polymer influence on the fine metal particles flocculation.
Photoluminescent copolymer‐pendant Ru(BPY)32+ grafted onto non‐woven silk fabric and its application to oxygen sensor
Authors: Kaneko Masao , Takekawa Toshihiro , Asakura Tetsuo 
Published: March 2011

AbstractCopolymer‐pendant Ru(bpy)32+ grafted onto silk fibroin was prepared by at first grafting copoly(4‐methyl‐4′‐vinyl‐2,2′‐bipyridine ‐ methylmethacrylate) onto non‐woven silk fabric, and then by reacting the grafted sample with cis‐Ru(bpy)2Cl2. Photoluminescence of this silk‐poly Ru complex and its quenching by oxygen were studied in gas, methanol and water phases. The relative emission intensity and the emission lifetime of the silk‐poly Ru showed that there are two kinds of sites for the Ru complex. The major, longer lifetime component (1070 ns, 77.1%, under Ar gas) is considered to be surrounded by polymer matrices, and the minor, shorter one (288 ns, 22.9%) seems to be exposed and is subjected to concentration quenching. The shorter lifetime species are quenched by oxygen more effectively than the longer ones. The mechanism of the quenching by oxygen and its application to oxygen sensor were discussed.
Conformational effects of polymer chains on the electron‐transfer reactions and luminescence behavior of Ru(bpy)3a+ in aqueous solutions of poly(acrylic acid)‐ and poly(methacrylic acid)‐bound Co (III) complexes
Authors: Kurimura Yoshimi , Sairench Yoshihiro , Nakayama Seiichi 
Published: March 2011

AbstractThe effects of the conformation of polymer chains on the electron transfer reactions and on the luminescence behavior of Ru(bpy)32+ in aqueous solutions of cis‐Co(A)PAA and cis‐Co(A)PMA ((A) = (en)2(OH2), en = ethylenediamine, PAA = poly(acrylic acid), and PMA = poly(methacrylic acid)) have been investigated by means of several spectrophotometric techniques. The results of the electron‐transfer reactions of the polymer Co(III) complexes with Cr(bpy)32+ and Fe(edta)2− revealed that, at low pH, part of the Co(III) complex moieties could hardly be reduced even in the presence of a large excess of the reducing agents when the degree of coordination of the Co(III) complex is very low. The magnitude of the degree of reduction of the Co(III) complex and the rate constants of the electron‐transfer reactions of Co(A)PMA are considerably affected by the conformational transition of the polymer chains.The luminescence behavior of Ru(bpy)32+ in aqueous solutions of these polymer complexes at around pH 5 are essentially explained by the spontaneous luminescence decay of the ex cited state of Ru(bpy)32+ ions which are localized in the compact form of the polymer chains and that of the non‐shielded ones which have a similar lifetime as in water. Effects of the conformational transition of Co(A)PMA chain on the luminescence intensity and the lifetime of the excited state of Ru(bpy)32+ are discussed in the light of the results obtained.
Influence of polymer matrices on the photoelectrochemical properties of a molecular semiconductor by structural modification
Authors: Schlettwein D. , Jaeger N. I. , Wöhrle D. 
Published: March 2011

AbstractThin films of phthalocyaninatozinc(II) (PcZn) have been prepared by physical vapor‐deposition or from solutions in organic solvents in mixture with poly(vinylidene fluoride) PVDF. The molecular order, i.e. the structure of the van der Waals bonded crystals, depends on the preparation technique and on the chosen matrix. By annealing the thin films or by embedding the phthalocyanine in a polymer environment, the structure is effected significantly. This is demonstrated by electronic spectra. The activities of the films have been investigated in the photoreduction of oxygen dissolved in an aqueous electrolyte. The highest sensitivities towards visible light are observed in matrices of polymers with a high dipole moment. Aside from the influence of a polar polymer towards a more favourable crystallization of PcZn an active role in the charge carrier generation process is derived from a discussion of the results within the model of molecular semiconductors which is appropriate for phthalocyanines.
Complexing ability of poly[5‐vinylsalicylidene‐2‐aminopyridine] towards different metal(II) salts
Authors: El‐Shekeil Ali , El‐Sonbati Adel Z. 
Published: March 2011

AbstractMononuclear and binuclear complexes of poly (5‐vinylsalicylidene‐2‐aminopyridine) a)were prepared with Copper(II), Cobalt (II), Nickel(II), Cadmium(II), dioxuranium(II) and Palladium(II) salts. The metal (II) acetates and palladium chloride gave mononuclear complexes, while cupric chloride gave a binuclear complex. The polymer complexes have been characterized on the basis of elemental analysis, u.v., i.r. and magnetic susceptibilty. The stereochemistry and the nature of the complexes are markedly dependent upon the mole ratio of the reactants and the anions. In all complexes the homopolymer was chelated to the metal ion via the nitrogen atom of the azomethine group and oxygen atom of the phenolic, group. The low value of the magnetic moment of binuclear copper complexes is due to the antiferromagnetic interaction between two adjacent copper atoms. The ligand field parameters are calculated and related to the electronic environments.
Palladium cluster catalysts supported on chelate resin‐metal complexes
Authors: Toshima Naoki , Teranishi Toshiharu , Saito Yasukazu 
Published: March 2011

AbstractThe dry beads of chelate resin‐metal complexes have been prepared from metal ions and the chelate resin containing iminodiacetic acid moieties. The surface area of the chelate resin can be increased both by washing with an organic solvent miscible with water and by complexing with multi‐valent cations. Palladium clusters are supported on the chelate resin‐metal complexes by two methods, in which the order is reversed between “complexing of metal ions” and “supporting of palladium clusters”. The supported palladium clusters catalyze the hydrogenation of C=C bonds, and the catalytic activity greatly depends on the metal ions used for the complexation. In the case of typical metal ions, the complexing of metal ions after supporting of palladium clusters makes the surface area of the resin increase, but makes the catalytic activity decrease compared with the reverse order. In the case of lanthanoid ions, on the other hand, the same order makes both the surface area and the catalytic activity increase.