bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymer education in korea
Authors: Jung Jin Chul 
Published: March 2011

AbstractThe present article deals with the education on polymer science and technology in Korea. It starts first in Middle Schools with introduction of plastics as an industrial material and their classification into thermoplastics and thermosets. Korean university‐level polymer educations are conducted in 17 universities having separate polymer departments as well as in those without polymer departments. In the former intensive education on polymers is conducted and in the latter various polymer courses are independently offered in various departments, merely as electives.
Dielectric relaxation spectroscopy in poly(ethylene oxide)/water systems
Authors: Kyritsis Apostolos , Pissis Polycarpos 
Published: March 2011

AbstractThe dielectric properties of poly(ethylene oxide) (PEO) are studied by dielectric relaxation spectroscopy measurements in wide ranges of frequency (5–2×109 Hz) and temperature (193 − 300 K). PEO/water systems are also studied in a wide range of water content h (0 − 0.85 grams of water per grams of dry PEO). The measurements allow to distinguish between the dipolar secondary mechanism γ and effects related to free charge motion. The data are analyzed within the formalisms of permittivity, ϵ*, and electric modulus, M*. The water has been found to plasticize the dipolar process and to affect strongly the conduction process. A critical water content hc, hc = 0.13, has been found for the mechanism of charge transport.
Understanding polymers by vibrational spectroscopy: Some recent advances in theory and experiment
Authors: Meier Robert J. 
Published: March 2011

AbstractA rapid‐scan version of 2D‐IR spectroscopy is introduced and applied to study the phases of an acrylonitrile‐butadienestyrene polymer system. Then, as the main part of this paper and in particular to stimulate further application in this field, some recent advances in the application of computational chemistry to the evaluation of vibrational spectra are presented. Some specific applications are discussed.
Polymers, additives, surfactants and their mixtures: Computer‐based search with special ftir libraries
Authors: Hummel Dietrich O. 
Published: March 2011

AbstractThis investigation was done with a PC of 850 MB/33 MHz, Windows 3.1 and the SPECTACLE program of LabControl/Cologne. The libraries contained standardized FTIR spectra of 3061 defined polymers, 530 industrial polymers and resins, 1969 additives (pigments, stabilizers, plasticizers etc.) 1190 surfactants and 1614 monomers, pyrolyzates and educts. For searches, the data density was reduced to 4/cm.Similarity search with standardized full spectra yields quantitative dissimilarity figures; it allows an experimental definition of identity. The derivative functions 3 and 4 of Lowry and Huppler increase the gap between identical and similar spectra. With the LH2 algorithm spectra are defined as identical if their dissimilarity values are within 103. Since all organic matter has some spectral similarity the LH2 dissimilarity for organics will not go far beyond 105. ‐ The quality of IR preparation has a strong impact on search results. If a library contains spectra with false‐light, Christiansen effect, high noise or other artefacts, peak search yields better results than similarity search with full spectra.Multicomponent systems can be searched successfully for their constituents with an algorithm combining peak and similarity searches. This algorithm is superior to all other algorithms if a library contains spectra with artefacts.
Evidence of electron acceptor ‐ electron donor interactions in thermoplastic polymer blends by using FTIR ‐ ATR spectroscopy
Authors: Brogly M. , Nardin M. , Schultz J. 
Published: March 2011

AbstractSpecific interactions in binary blends of ethylene/vinyl acetate copolymer (EVA) with various low molecular weight terpene‐phenol tackifying resins (TPR) were systematically investigated, as a function of the composition of the blend and of the electron‐acceptor ability of the resin, by using attenuated total reflection‐Fourier transform infrared (ATR‐FTIR) spectroscopy. Molecular acid‐base were evidenced between TPR hydroxyl groups and EVA carbonyl groups. Quantitative information on the fraction of acid‐base bonded entities, the enthalpy and the equilibrium constant of pair formation were obtained. A crystalline transition of the EVA copolymer is observed and is discussed in terms of enthalpy and entropy considerations based on FTIR and calorimetric differential scanning calorimetry (DSC) investigations. Fundamental results are then summarized in order to predict the interfacial reactivity of such polymer blends towards acid or basic substrates.
Applications of photoacoustic step‐scan FT‐IR spectroscopy to polymeric materials
Authors: Gregoriou Vasilis G. , Hapanowicz Rick 
Published: March 2011

AbstractThin coatings technology demands that characterization tools are readily available to distinguish between the composition and physical state of the coated layers versus the substrate. In principle, infrared photoacoustic spectroscopy (PAS) possesses all the appropriate features to become a mainstream technique for these types of characterizations. These features include the ability to characterize coatings of a variety of thickness (monolayers to tens of microns) and the fact that the technique requires virtually no sample preparation. One category of such samples involves systems having few micron thin layered structures coated on relatively thick polyester substrates. The phase delay of the photoacoustic signal can be used in conjunction with the knowledge of the thermal properties of the coated fluids in the calculation of the relative as well as the absolute depths of these multi‐layered coatings. The phase delay is calculated at wavelengths that are characteristic of the various components of the different layers in the system. The technique is applied to the characterization of a coated system having a submicron layer as the top layer. Step‐scan FT‐IR photoacoustic data are presented that prove the ability of the technique to successfully isolate the infrared signature of the top layer from the infrared spectrum of the bulk material, proving the sub‐micron resolution capability of the method. In addition, results will be shown that underline the fact that the most serious problem in PAS is saturation at high absorptivities.
Analysis of polymer mobility by fluorescence spectroscopy
Authors: Klopffer Marie‐Hélène , Bokobza Liliane , Monnerie Lucien 
Published: March 2011

AbstractFluorescence spectroscopy using an intramolecular excimer‐forming probe has been used to investigate chain mobility in various polybutadienes. The spectroscopic technique is completed by a rheological study carried out in order to identify the molecular parameters governing polymer dynamics. The temperature dependence of the correlation time of the probe motion can be fitted to a WLF equation which shows that the probe mobility reflects the glass transition phenomenon of the host matrix.
Mechanical spectroscopy study on biodegradable synthetic and biosynthetic aliphatic polyesters
Authors: Choi Hyoung J. , Kim Jung H. , Kim Jinho , Park Sung H. 
Published: March 2011

AbstractMiscibility behavior and rheological properties with mechanical spectroscopy study of both poly(3‐hydroxybutyrate) (PHB)/poly(ethylene oxide) (PEO) and biodegradable synthetic aliphatic polyester (BDP)/linear low density polyethylene (LLDPE) were investigated. Blends of BDP with LLDPE were immiscible, showing two separate Tg values in all compositions; whereas blends of PHB with PEO were miscible, showing a single Tg in the whole range of compositions. However, the shear viscosities of both synthetic and biosynthetic blend systems decrease with increasing shear rate. When a modified Cole‐Cole plot of the blend system is further considered, the logG′‐logG” plot shows little sensitivity to a variation in both LLDPE composition for synthetic BDP and PEO composition for biosynthetic PHB. Poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (P(3HB‐co‐3HV)) random copolymers were also investigated.
Infrared absorption spectra of polymers from classical molecular simulation
Authors: Soldera Armand , Dognon Jean‐Pierre 
Published: March 2011

AbstractA method is proposed to predict the infrared spectra of amorphous polymers. Based on classical molecular simulation and Kramers‐Kronig relations, it allows the computations of absorption and transmittance spectra of polymer films in near and middle infrared domains with good agreement with experimental data.
Heterogeneous anionic coordinated polymerization of propylene oxide: A quantitative 13c NMR analysis of the regio‐ and stereo‐selectivity of the catalyst via microstructure analysis of polymers
Authors: Goriot R. , Pétiaud R. , Llauro M. F. , Hamaide T. 
Published: March 2011

AbstractPoly(propylene oxide)s synthesized with an heterogeneous catalytic system have been analyzed by 13C NMR spectroscopy by using DEPT experiments and sub‐spectrum editing techniques. The results have been compared with those obtained from commercial products, in order to reach a greater insight into the selectivity of the catalytic system. A quantitative and reliable determination of the inversion ratio is proposed, which implies each type of carbon as well. This inversion ratio was found to be much higher than that observed in commercial PPO. It is shown that when the inversion ratio is no longer negligeable, its accurate determination is a prerequisite to a reliable approach of the tacticity distribution in regular sequences. So, a quantitative determination of the configurational diad and triad distribution is proposed which takes into account the fraction of “defect” resonances (consequence of inverted addition) overlapping with “normal” resonances (unaffected by the inverted addition) in the different sub‐spectra. The main features of the catalyst activity are outlined and compared with results obtained with commercial PPO.
FTIR and micro‐Raman spectra of polymer nanostructures under pressure
Authors: Afanasyeva N. I. , Belogorokhov A. I. , Blank V. D. , Jawhari T. , Ovchinnikov A. A. 
Published: March 2011

AbstractStudies of metastable C60 forms obtained at high pressures and temperatures and other polymer carbon structures up to nanostructures have been performed over a wide spectral range using FTIR and micro‐Raman techniques. FTIR spectra of carbon‐based polymer materials (pristine fullerenes, nanostructures, and diamond‐like C60 forms) were studied in the range from 1600 to 300 cm−1.The micro‐Raman spectra of the carbon‐based materials and their new forms obtained under the conditions of high energy impacts allowed us to determine the level of disorder in these polymer forms of carbon and to study the formation of new structures up to superhard ones.
Spectroscopic characterization of the conversion of poly(p‐phenylene‐vinylene) precursor by ion irradiation
Authors: Davenas J. , Massardier V. , Tran V. H. , Nguyen T. P. 
Published: March 2011

AbstractDifferent spectroscopic techniques show that poly(p‐phenylene vinylene) films can be derived from a sulphonium precursor by irradiation with ion beams at energies of the order of 100 keV. The comparison with the pyrolysis conversion shows less chlorine and sulfur residues in the irradiated thickness, whereas some ketone structures are evidenced. The formation of nanometric scale carbon clusters induced by the irradiation degradation of PPV is however indicated by UV spectrophotometry, leading to bandgap narrowing and increase of the conductivity. The irradiation with doping species allows the conversion and doping of PPV films in a single stage. The induced conductivity is limited by the formation of complexes with chlorine residues through a gettering process.
FTIR&ATR analyses on a polypropylene (pp) surface after plasma treatment in the study of chitosan surface grafting to improve PP dyeing behaviour
Authors: Rochery M. , Lam T. M. , Crighton J. S. 
Published: March 2011

AbstractThis study consisted in working on the treatment of a polypropylene (PP) film surface to improve its dyeing behaviour. A plasma treatment was carried out to try to create oxidizing groups on this surface, so that it could be then easier to apply a specific polysaccharide: chitosan which is reported to be much more reactive than PP and easy to dye. A study about the various parameters of the plasma instrument was necessary to find the optimal treatment. The possible formed oxidizing groups were emphasized by FTIR&ATR analyses. Chitosan was applied after the plasma treatment and the dyeing result which was then observed, was quite encouraging in certain conditions.
Use of fluorescent probes (pyrene and molecular rotor) for the detection of hydrophobic microdomains in amphiphilic polymers aqueous solutions
Authors: Benjelloun Abdesselam , Damas Christine , Dziadosz Laure , Adibnejad Mohammad , Brembilla Alain , Carré Marie‐Christiane , Viriot Marie‐Laure , Lochon Pierre 
Published: March 2011

AbstractThe purpose of the present investigation deals with a comparative study between the magnitudes of the local viscosity and/or the polarity of the hydrophobic microdomains generated by poly (3‐hexadecyl‐1‐vinylimidazolium bromide) in an aqueous medium using a cinnamylidene molecular rotor and pyrene as fluorescent probes. Moreover, the results are compared with the data obtained with micelles of conventional surfactants such as the homopolymer repetitive unit model and CTAB.
13C, 25Mg and 11B solid‐state NMR study of a fire retarded ethylene‐vinyl acetate copolymer
Authors: Pécoul Nathalie , Bourbigot Serge , Revel Bertrand 
Published: March 2011

AbstractFlame retardance of ethylene‐vinyl acetate copolymer (EVA) can be achieved using magnesium hydroxide (Mg(OH)2) incorporated in the polymeric matrix. The adduct of small amount of zinc borate as synergistic agent in the formulation increases the fire‐proofing properties. Multinuclei solid‐state NMR appears as a powerful means to characterise materials before and after combustion. We show that endothermic dehydration, water vapour evolved and formation of a glassy coating provide the flame retardancy of interest to the polymeric matrix.
Characterization of a poly(ethersulphone) by on‐line coupling of size exclusion chromatography with NMR and FTIR spectroscopy
Authors: Eichhorn Klaus‐Jochen , Voigt Dieter , Komber Hartmut , Pospiech Doris 
Published: March 2011

AbstractAn on‐line detection „on the flow”︁ during the size exclusion chromatography run using FTIR and NMR spectrometers was applied to investigate the liquid chromatographic separation process of oligomers and to identify the separated chromatographic compounds. The FTIR and NMR detectors give real‐time information about the chemical structure and functional groups of the eluated species. The preferences and limits of the on‐line coupling were discussed using an oligomeric hydroxyl terminated poly(ethersulphone) as an example. Molecular weights could be calculated from the 1H‐NMR spectra of the separated species using the intensities of end‐group and main‐chain signals. Residues of N‐methylpyrrolidone which was used as solvent in the oligomer synthesis were identified by the FTIR detector.
NMR investigations on dynamical aspects of aging processes in elastomers
Authors: Denner Paul , Walter Bernd , Willing Theo 
Published: March 2011

AbstractProton spin relaxation measurements have been used to investigate the effect of aging on local and coherent segmental dynamics in cis‐1,4‐polybutadiene samples. The polymer chains in bulk polybutadiene were crosslinked by exposure to ionizing radiation. The transition of the 1H‐n.m.r. signal from a liquidlike spin system response to a solidlike one is due to crosslinking and network formation by the irradiation and depends on the radiation dose. It is shown that the radiation yields changes in the constrained defect diffusion processes modelling the chain dynamics. Correlation time and memory time for the local and coherent segmental motion strongly depend on radiation dose.
Molecular weight dependent antimicrobial activity by Chitosan
Authors: Tokura Seiichi , Ueno Keisuke , Miyazaki Satoshi , Nishi Norio 
Published: March 2011

AbstractChitosan oligomers of average molecular weight 9300(P9300) and 2200(P2200) were prepared by nitrous acid degradation followed by the reduction of 2,5‐anhydromannose terminal by sodium borohydrate. Although P9300 provided the growth inhibition of Escherichia coli, P2200 was not growth inhibitor but growth accelerator. The stacking of P9300 to cell wall of E. coli was confirmed by the use of FITC(Fluorescein isothiocyanate) labeled chitosan oligomer using the Confocal Laser Scanning Microscope. The permeation of P2200 was also observed through cell wall without stacking to cell wall. The effective growth inhibition of bacteria was assumed to be the prevention of delivery of nutrition through cell wall.
Biodegradation of chitin with enzymes and vital components
Authors: Takamori Yoshimori , Morimoto Minoru , Sashiwa Hitoshi , Shigemasa Yoshihiro , Okamoto Yoshiharu , Minami Saburo , Matsuhashi Akira 
Published: March 2011

AbstractChitin from squid pen was effectively degraded by the chitinase from Bacillus sp. PI‐7S, while the degradation of chitin with lysozyme proceeded very slowly. Among the various vital components studied, the degradation of chitin from squid pen was performed not by canine serum, canine tela subcutanea, canine tela liver, and equine serum but by bovine serum and caprine serum. Noteworthy is the fact that chitin sponge subcutaneously implanted in dog reported not to have chitinase was degraded in ca. 14 days.
Synthesis of two water‐soluble polysaccharides by Acetobacter sp. NCI 1005
Authors: Tajima Kenji , Uenishi Nobuto , Fujiwara Masashi , Erata Tomoki , Munekata Masanobu , Takai Mitsuo 
Published: March 2011

AbstractA new polysaccharide was isolated from the culture of Acetobacter aceti subsp. xylinum (A. xylinum) NCI 1005 grown on sucrose. The structure of the polymer was analyzed by nuclear magnetic resonance (NMR) spectroscopy. The water‐soluble polysaccharide (WSP) was determined to be β(2, 6) linked polyfructan, which was structurally different from the polymer synthesized from glucose instead of sucrose by the same strain. The discovery of the new polysaccharide has elucidated that the bacterium has the ability to synthesize two different kinds of water‐soluble polysaccharides.
Starch biosynthesis and modification of starch structure in transgenic plants
Authors: Koßmann J. , Emmermann M. , Frohberg C. , Lloyd J. R. , Lorberth R. , Springer F. , Willmitzer L. , Büttcher V. , Abel G.J.W. , Duwenig E. , Welsh T. 
Published: March 2011

AbstractStarch is synthesised through the ADP‐glucose pathway, involving the three enzymes ADP‐glucose pyrophosphorylase, starch synthase and starch branching enzyme. ADP‐glucose pyrophosphorylase is the key enzyme of the pathway, determining the flux of carbon into starch. It generates ADP‐glucose, which is the substrate for the starch synthases, from glucose‐1‐phosphate and ATP releasing pyrophosphate. The enzyme is stimulated by 3‐phosphoglycerate and inhibited through inorganic phosphate. The starch synthases, which catalyse the transfer of glucose from ADP‐glucose to the nonreducing end of a growing α‐1,4‐glucan, are divided into two classes, the granule‐bound starch synthases (GBSS) and the soluble starch synthases (SS). In both classes several isoforms have been described from many different plant species. The branching enzyme, which introduces branchpoints into the amylopectin, can also occur in different isoforms. Other enzymes present in plants, which also act on α‐1,4‐glucans, such as the starch phosphorylases, disproportionating enzyme and different starch hydrolases, might also be important for dertermining the starch structure and, therefore, its processibility. Many aspects of starch synthesis are not fully understood to date. Starch metabolism can be manipulated through genetic engineering, either by the ectopic expression of different heterologous genes, or through the repression of the expression of endogenous genes using antisense RNA technology. This not only allows the functional analysis of starch biosynthetic proteins, but also the manipulation of starch structure in order to widen its industrial applications.In this way many different potato lines have been generated, containing either different amounts of starch, or which synthesize a structurally modified starch. These structural changes relate to the amylose content, the phosphate content, or the gelatinisation and gelation characteristics of the starch.
Solution properties of cellulose tris(3,5‐dimethyl‐phenylcarbamate)
Authors: Norisuye Takashi , Tsuboi Akihiko , Sato Takahiro , Teramoto Akio 
Published: March 2011

AbstractThe dilute‐solution behavior and liquid crystal formation of cellulose tris(3,5‐dimethylphenylcarbamate) (CTDC) in 1‐methyl‐2‐pyrrolidone (NMP) at 25°C are discussed by summarizing our recent studies, and its molecular characteristics are compared with those of cellulose tris(phenylcarbamate) (CTC) in the same solvent. The molecular weight dependences of optical anisotropy factor, radius of gyration, intrinsic viscosity ([η]), and isotropic‐cholesteric phase boundary concentration for CTDC are explained consistently by current theories based on the wormlike chain. An analysis of the newly measured [η] for CTC shows that the backbone conformation and chain stiffness are substantially the same for the two cellulose derivatives in NMP. However, a distinct difference in optical anisotropy is found and briefly discussed in relation to the higher optical resolution capacity of CTDC than that of CTC in chromatographic separation of racemic compounds.
Preparation and anticoagulant surface properties of glucoside‐ or sulfated glucoside‐bearing polymer grafted poly(ethylene) films
Authors: Sakamoto Nobuyuki , Shioya Tomoko , Kishida Akio , Akashi Mitsuru 
Published: March 2011

AbstractPoly(GEMA) or poly(GEMA)‐sulfate grafted surfaces were prepared for the purpose of developing biomaterials with anticoagulant surfaces. Their functionalities were investigated as anticoagulant activity, proteins and cells adhesion activity, and complement activation activity. These results revealed that the adhesion of blood cells onto a GEMA‐sulfate grafted surface was due to protein adsorption and that complement activation onto a GEMA‐sulfate grafted surface was larger than that on a GEMA grafted surface. A GEMA‐sulfate grafted surface, however, exhibited good anticoagulant activity. These functions seemed to be due to the specific functionality of the SO3 groups in a GEMA‐sulfate.
Methyl‐hydroxypropyl cellulose ‐ shear induced birefringence measurements in the semi–dilute regime
Authors: Schmidt Jürgen , Weigel Richard , Burchard Walther , Richtering Walter 
Published: March 2011

AbstractThe present study was induced by unexpected findings with this and other not fully substituted cellulose derivatives. Although fully transparent aqueous solutions were prepared, static light scattering (LS) revealed a strong aggregation. A detailed analysis of the LS‐data as well as transmission electron‐microscope pictures gave evidence for fringed micelles as aggregate structure. These particles consist of several side‐by‐side aligned chains that form a compact core from which many dangling chains emerge. The core in this model has a geometrical anisotropic shape and flow birefringence became detectable when orienting the particles by the action of shear forces. Induced flow birefringence is a common feature of many other materials and therefore a set‐up was constructed that could be attached to a common constant stress rheometer of Bohlin. The reported experiments present first examples measured with this set‐up and demonstrate the efficiency of this technique. In the following the equipment is briefly described and the results obtained so far are tentatively interpreted.