bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new class of multifunctional poly(1, 6‐heptadiyne)‐based materials by metathesis polymerization
Authors: Choi Sam‐Kwon , Lee Ji‐Hoon , Kim Hwan‐Kyu 
Published: March 2011

AbstractA new class of multifunctional polymers based on poly(1, 6‐heptadiyne) derivatives with various functional groups such as carbazole unit for photoconductive polymers and nonlinear optical (NLO) chromophores for NLO polymers were synthesized by metathesis polymerization. The polymerizations were carried out with MoCl5‐ and WCl6‐based catalysts. The catalytic activity of MoCl5 was found to be greater than that of WCl6. The resulting polymers exhibited photoconductivity and large optical nonlinearity. These conjugated polymers have good solubility in common organic solvents, long‐term stability toward air oxidation, and high electrical conductivity.
Structure‐property behavior of polyurethanes, polyurethane ionomers, and their acrylates
Authors: Kim Byung Kyu 
Published: March 2011

AbstractPolyurethanes(PU), PU ionomers, PU ionomer acrylates, PU latex interpenetrating polymer network(LIPN), latex AB crosslinked polymers (ABCP), and uv‐curable PU ionomer acrylates have been prepared and characterized in terms of structure‐property relationship, together with shape memory function of PUs.
Polymers with macrocyclic architectures: Synthesis and properties
Authors: Deffieux Alain , Beinat Sylvie , Schappacher Michel 
Published: March 2011

AbstractThe preparation by living polymerization and the investigation of the properties of polymers with cyclic chain architectures have been recently undertaken. The cyclization involves a unimolecular end‐to‐end reaction of a heterodifunctional linear precursor. The elementary steps of the cyclization mechanism are examined in the light of matrix‐assisted laser desorption/ ionization mass spectrometry (MALDI‐MS) data obtained on linear polystyrene precursors and cyclized products. The synthetic procedures developed to prepare macrocyclic polymers of various structures, as well as macrocyclic random and block copolymers are then reviewed and discussed. The main characteristics of the cyclic (co)polymers are compared to the corresponding linear chains and some of the original properties that are induced by the cyclic chain architecture are presented.
Synthesis of a liquid crystalline semi‐ordered aromatic polyester and high‐resolution solid‐state 13c nmr investigation of local motions
Authors: Jo Byung‐Wook , Jin Jung‐Ii , Laupretre Francoise 
Published: March 2011

AbstractA liquid crystalline sequence‐ordered polyester was prepared from isophthalic acid and 4‐hydroxyphenyl 4‐hydroxybenzoate in a 1:1 mole ratio. The local motions of this polymer were investigated by high‐resolution solid‐state 13C NMR and the results were compared to data obtained on liquid crystalline or semicrystalline random terpolyesters with very similar compositions. Whereas no motions of the hydroquinone rings could be detected below the glass‐transition temperature of the semi‐ordered polymer, the para‐hydroxybenzoic acid units exhibit a certain degree of freedom in the temperature range between 450 K and 500 K.
Processing of high density polyethylene and poly(ethylene terephthalate) blends
Authors: Basu Sumit , Kale Dwarkanath D. 
Published: March 2011

AbstractCommercial grades of high density polyethylene, HDPE and waste poly(ethylene terephthalate), PET were melt blended over a wide range of compositions. Effect of ethylene acrylic acid copolymer, EAA, ethylene vinyl acetate copolymer, EVA and maleic anhydride grafted EVA as compatibilizers on rheology and mechanical properties of the blend was studied. EAA was found most suitable compatibilizer.
Free volume studies in miscible polymer blend systems
Authors: Campbell Jonathon A. , Goodwin Y. A. , Ardi Mohsen Safari , Simon George P. , Landry‐Coltrain Christine J. T. 
Published: March 2011

AbstractThis paper summarises the currently available literature concerned with measurement of free volume in miscible, amorphous polymer blends using positron annihilation lifetime spectroscopy (PALS) which probes excluded volume at the angstrom level. Previously reported data is compared with new data from a range of different blend systems. Miscible blends tend to show a negative deviation of free volume size (and to a lesser degree free volume fraction) on mixing due to the intimacy of packing of the blend component macromolecules. A largely immiscible system is also reported and shows a different behaviour (positive deviation of free volume size) and this is ascribed to additional free volume at the interface.
Application of thin films of conjugated polymers in novel light‐emitting devices and liquid crystal “light‐valves”
Authors: Macdiarmid Alan G. , Avlyanov Jamshid K. , Huang Feng , Huang Zheyuan , Wang Hsing‐Lin , Wang Pen‐Cheng , Epstein Arthur J. 
Published: March 2011

AbstractLight‐emitting electroluminescent diodes and electrochemically‐driven electroluminescent devices involving conjugated polymers are described. The effect on the properties of polypyrrole films (deposited from aqueous polymerizing solutions of pyrrole) caused by the hydrophilicity/hydrophobicity of the substrate surface is utilized by a “microcontact printing” technique to form patterned liquid crystal display devices.
Multifunctional polymers as multi‐role materials for photonics
Authors: Prasad Paras N. , Bhawalkar Jayant D. , Kumar N. Deepak , Lal Manjari , Cheng Ping Chen 
Published: March 2011

AbstractMultifunctional polymers can play multi‐roles such as laser light source, passive interconnects, optical signal processing and optical data storage in the development of photonics technology. In this paper, two approaches to achieve nanostructure control to introduce multifunctionality at both molecular and bulk levels are presented. A novel concept of multiphasic nanostructured composites is discussed. Various applications of a specific multifunctional property introduced by strong two‐photon absorption and efficient fluorescence are presented. The combined action of these two functions produces upconverted emission. Specific applications discussed are upconversion lasing, optical data storage, confocal microscopy, and photodynamic therapy.
Electronic structures of some novel functional polymers
Authors: Yamabe Tokio , Bakhshi A. K. , Yamaguchi Yoichi , Ago Hiroki 
Published: March 2011

AbstractThe electronic and geometric structures of some novel donor‐acceptor polymers containing alternating electron donating group X (X=CH2, SiH2, S, O or NH) and electron accepting group Y (Y=>C=CH2, >C=O, >C=CF2 or >C=C(CN)2) along the conjugated cis‐polyacetylene backbone, obtained on the basis of the one‐dimensional tight‐binding self‐consistent field‐crystal orbital (SCF‐CO) method at the MNDO‐AMl level of approximation, are presented.
Negative cilia model for biocompatibility: Sulfonated peo‐grafted polymers and tissues
Authors: Kim Young Ha , Han Dong Keun , Park Ki Dong , Kim Soo Hyun 
Published: March 2011

AbstractTo improve the biocompatibility of polyurethane (PU) and bioprosthetic tissue (BT), they were chemically grafted with a hydrophilic poly(ethylene oxide) (PEO) and further negatively charged sulfonate groups (SO3) to produce PU‐PEO‐SO3 and BT‐PEO‐SO3, respectively. PU‐PEO‐SO3 was much more blood compatible than untreated PU and PU‐PEO, and the degree of surface cracking and calcification on implanted PUs was decreased in the following order: PU > PU‐PEO > PU‐PEO‐SO3. Also, less calcium deposition of BT‐PEO‐SO3 than that of BT control was observed in in vivo animal tests. Such superior blood compatibility, biostability, and anticalcification of sulfonated PEO‐grafted PUs and tissues might be attributed to synergistic effects of nonadhesive and mobile PEO and negative sulfonate acid groups via a negative cilia model.
Surface thermomechanical and glass transition temperature measurements of polymeric solids
Authors: Kajiyama Tisato , Tanaka Keiji , Takahara Atsushi 
Published: March 2011

AbstractThe surface molecular motion of polymeric solids was investigated on the basis of scanning force microscopic and temperature‐dependent X‐ray photoelectron spectroscopic measurements. The surface of the monodisperse polystyrene films was in a glass‐rubber transition state even at 293 K in the case of number‐average molecular weight less than ca. 30k. The surface glass transition temperature, Tgs for the symmetric poly(styrene‐block‐methyl methacrylate) diblock copolymer films were much lower than those for the bulk samples. A remarkable depression of Tg at the air‐polymer interface was explained by the surface localization of chain end groups.
Order within order: Studies of semifluorinated block copolymers
Authors: Ober C. K. , Wang J. G. , Mao G. P. 
Published: March 2011

AbstractSeveral new semifluorinated compounds and polymers modified with these groups were synthesized and investigated. The polymer supports for these mesomorphic groups were styrene‐diene block copolymers in which the semifluorinated groups were attached to a hydroxy‐modified diene block. The characteristics of the smectic phase formed and its effect on the self‐ordering behavior of the block copolymers were examined.
Structural effects on biodegradation of aliphatic polyesters
Authors: Doi Yoshiharu , Abe Hideki 
Published: March 2011

AbstractVarious types of aliphatic polyesters were prepared by both biosynthetic and chemosynthetic methods, and their biodegradation tests were carried out under aerobic conditions in the river water. Biodegradabilities of polyester films were evaluated by monitoring the time‐dependent changes in the biochemical oxygen demand (BOD), weight loss (erosion) of polyester film, and dissolved organic carbon concentration (DOC) of test solution. The microbial copolyesters were degraded in the river water at a rapid rate, and the weight‐loss‐ and BOD‐biodegradabilities of the majority of biosynthetic polyesters were 100 % and 80±5 % for 28 days, respectively. In contrast, the biodegradabilities of chemosynthetic polyesters were strongly dependent of the chemical structure of monomeric units.
Potential of two‐dimensional near‐infrared correlation spectroscopy in studies of pre‐melting behavior of nylon 12
Authors: Ozaki Yukihiro , Liu Yongliang , Noda Isao 
Published: March 2011

AbstractThis review paper discusses the potential of generalized two‐dimensional (2D) near‐infrared (NIR) correlation spectroscopy in studies of pre‐melting behavior and hydrogen bonds of nylon 12. A 2D NIR study on dissociation and hydrogen bonds of N‐methylacetamide (NMA) is also reviewed here as a model compound study of nylon 12. Fourier transform (FT)‐NIR spectra in the region of 9000–5000 cm−1 of nylon 12 were measured over a temperature range of 30–150°C where gradual weakening of inter‐ or intramolecular associative interactions and decrease of local order leading to the eventual fusion of nylon 12 crystals are observed. The 2D correlation analysis provided the following conclusions for the pre‐melting behavior of nylon 12. (i) There are at least eight bands in the 6800–6100 cm−1 region assignable to free‐ and hydrogen‐bonded NH groups of nylon 12 in various environments. The asynchronous 2D correlation spectrum in the above region indicates that the amide groups with free carbonyl oxygen appear first and then the unassociated free amide and amide groups with free NH follow as the temperature is increased. (ii) The asynchronous spectrum in the 6000–5500 cm−1 region, where the first overtones of the CH2 stretching modes are expected to appear, indicates that substantial amount of disordered or dissociated components start appearing before the disappearance of more ordered components. It seems that they appear as the pre‐melting precursors (or even possibly as the indirect cause) to the precipitous decrease of the ordered components associated with melting of nylon 12 occurring at a much higher temperature.
Creep rate spectroscopy using a laser interferometer as ultra‐high resolution technique for study of relaxations
Authors: Peschanskaya Nina N. , Yakushev Pavel N. , Sinani Alfred B. , Bershtein Vladimir A. 
Published: March 2011

AbstractAn original laser‐interferometric Creep Rate Spectroscopy (CRS) method has been developed and used as the low‐frequency and high‐resolution technique for studying of microplasticity and relaxations in different materials including brittle ones. New possibilities of CRS for polymers are demonstrated.
Dispersion of normal modes in cis 1,4 polybutadiene
Authors: Wadhwani Navina , Tandon Poonam , Gupta Vishwambhar D. , Rastogi Shantanu 
Published: March 2011

AbstractAmong the synthetic polymers of commercial potential, poly‐butadiene is an important rubbery material and it encompasses the bulk elastomers in use. To the best of our knowledge, a complete normal coordinate analysis with full phonon dispersion curves for cis 1,4 polybutadiene (CPBD) have not been reported so far. In the present communication, we report a complete normal coordinate analysis with full dispersion curves, density‐of‐states and calculation of heat capacity. The normal coordinate analysis has been carried out using the Urey‐Bradley force field and the Wilson's GF matrix method as modified by Higgs. A comparison has been made with trans 1,4 polybutadiene (TPBD). The prominent features of the dispersion curves like crossing over and regions of zero‐slope away from the zone centre are discussed. To check the validity of the force field used and the assignments, normal mode calculations are also performed for unsaturated C‐deuterated and fully deuterated CPBD.
The diffusion of water into pet followed in‐situ using FT‐IR ATR
Authors: Sammon Christopher , Everall Neil , Yarwood Jack 
Published: March 2011

AbstractThe diffusion of water into PET containing a comonomer has been followed in‐situ using FT‐IR ATR. Varying degrees of crystallinity were induced into the polymer by annealing at 85°C (above the glass transition temperature). The diffusion coefficients were calculated by a least squares fit of the experimental diffusion data to theoretical sorption curves and are found to decrease with increased crystallinity. Some evidence for a crystalline ‘skin’ is discussed.
Cationic polymerization of 1,3‐pentadiene I. infrared, 1H‐NMR and 13C‐NMR investigations on the microstructure of poly(1,3‐pentadiene) synthesized with cationic catalysts
Authors: Vautrin‐Ul Christine , Pla Fernand , Petit Alain 
Published: March 2011

AbstractThis study deals with cationic polymerization of the cis‐ and trans‐isomers of 1,3‐pentadiene. The microstructure of the polymer chains is studied by 1H‐NMR, 13C‐NMR and IR spectroscopies. It is shown that the trans‐diene gives strictly trans‐1,4 and trans‐1,2 residual linear insaturations, whereas the cis‐isomer yields also cis‐1,4, cis‐1,2 and 3,4‐units whose overall content can reach 10 mol‐%. According to the cyclization degree of the macromolecules, ranging from 30 to 70 mol‐%, the number of trans‐(1,2+1,4) units varies between 33 to 65 mol‐% and that of trans‐1,2 units between 4 and 20 mol‐%. An analytical method is proposed to evaluate the average number of rings present in the polycyclic sequences. It is found that the cyclic fragments of the polymer chains consist of bi‐ or tri‐cyclohexane fused rings containing α tetrasubstituted double bond.
Stability under γ irradiation aging of an EPOXY/AMINE resin embedding simulated nuclear waste: Critical assessment of the techniques investigating chemical structure (IR and SIM spectroscopies) and bulk properties (DMA, DSC)
Authors: Stevenson I. , Colombini D. , Debré O. , Thomas J. P. , Romero M. A. 
Published: March 2011

AbstractIn order to predict the long term behaviour of materials simulating embedded nuclear waste (concentrate of evaporated radioactive effluents, mixture of anionic and cationic exchange resin), several techniques have been used:
— Infrared and HSF‐SIMS spectroscopies to investigate chemical structure: no significant differences have been observed between irradiated epoxy resin matrix samples and non‐irradiated ones. No structural modification in the materials have been evidenced but some ion exchange resin irradiated in water seem to trap chlorine while releasing their borate content.
— Dynamic mechanical analysis (DMA) to follow the irradiation effect on relaxational mechanisms. A small increase of the temperature Tα associated with the glass transition temperature for a weak total dose whereas a decrease of Tα for greater doses have been detected (these variations are however close to measurement errors).
— Differential scanning calorimetry (DSC) to follow the thermal behaviour of the γ irradiated simulated radioactive materials: DSC results agree with those obtained using DMA.
FTIR analysis of cysteic acid and cysteine‐S‐thiosulphate on untreated and bleached human hair
Authors: Signori Vittoria , Lewis David M. 
Published: March 2011

AbstractHuman hair was analysed by FTIR spectroscopy and single fibre analysis was achieved using an IR microscope, an ATR diamond cell was also found very useful in determining the cysteic acid content of hair tress samples. Several different data manipulations were also assessed.
Macromolecules in ordered media. 6. Effect of the phospholipidic bilayer composition on poly (2‐vinyl pyridine) ‐ liposome association
Authors: Porcar Iolanda , García Rosa , Soria Vicente , Abad Concepción , Campos Agustín 
Published: March 2011

AbstractThe intrinsic fluorescence emission of poly (2‐vinyl pyridine) has been exploited in order to gain insight into the nature of the interaction with artificial membranes. In this contribution, the study has been focused on the effect of the phospholipid bilayer composition on the association to the polymer. Fluorescence data have been converted into association isotherms and then analyzed in terms of both binding and partition models. Results show that the association is enhanced by the presence of negative charged phospholipid as a constituent of the liposomal membrane. The strong surface density dependence of the polymer‐liposome association indicates the predominantly electrostatic nature of that interaction.
Ordering and mobility of ferroelectric liquid crystal dimer as studied by FT‐IR spectroscopy with 2D‐IR correlation analysis
Authors: Shilov Sergej V. , Skupin Holger , Kremer Friedrich , Wittig Tobias , Zentel Rudolf 
Published: March 2011

AbstractBoth a conservative rapid‐scan FT‐IR technique and a novel step‐scan FT‐IR technique with 2D correlation analysis were used to study the orientation and the mobility of a ferroelectric liquid crystal dimer during switching under an electric field. The detailed mutual arrangements of different molecular segments (mesogen, poly(methylene) chain, polysiloxane chain) in a smectic C* phase were derived from the static spectra. It was shown that the long mesogen axis, the average poly(methylene) and the average polysiloxane chain axes do not coincide with each other. The hindered rotation of the carbonyl group is confirmed. Time‐resolved FT‐IR technique was used to follow the segmental motion with a time resolution of 5 μs. The temperature and electric field strength dependencies of the mobility of these segments are discussed. 2D correlation analysis of time‐resolved data reveals small differences in the behavior of the carbonyl and the benzoic rings in the mesogen moieties, that can be explained as differences in the orientation distribution functions of these moieties.
Chemical analysis of polymers using transmission electron microscopy/electron energy‐loss spectroscopy: The example of poly(ethylene terephthalate)
Authors: Varlot Karine , Martin Jean‐Michel , Quet Christian , Kihn Yolande 
Published: March 2011

AbstractWe have performed EELS analysis of poly (ethylene terephthalate) (PET) in the analytical TEM in order to evaluate the possibility to obtain chemical analysis of the polymer at sub‐micrometer scale. Due to irradiation damage, it revealed necessary to work at the lowest possible electron dose, typically below 103 C.m−2, and with the specimen cooled to liquid nitrogen temperature. In the acquired spectra, we propose an identification of the different chemical bondings in agreement with XANES experiments.
Small‐angle X‐ray scattering and rheological characterization of alginate gels
Authors: Stokke B. T. , Drager K. I. , Yuguchi Y. , Urakawa H. , Kajiwara K. 
Published: March 2011

AbstractThe wide applicability of alginates is due to the ease of which gelation can be introduced and that the gelation conditions are compatible with requirements imposed by for instance living cells. The “egg‐box” model describes the gel‐inducing ions embodied in cavities formed by sequences of α‐L‐GulA of the alginate copolymers in a pairing reaction yielding junction zones. Small‐angle X‐ray scattering showed that the cross‐sectional radius of gyration for an alginate with fraction of α‐L‐GulA, FG, = 0.39, increased from Rg,c = 3.5Å for alginate in solution to 7.6Å for homogeneous Ca‐gels at [Ca2+] = 10 mM. The homogeneous Ca‐alginate gels were obtained by in situ release of Ca2+ from Ca‐EGTA or CaCO3 using a slowly hydrolyzing lactone. Either increasing the [Ca2+] for a given FG or increasing FG by selection of an alginate from a different seaweed specie and using constant [Ca2+], yielded larger initial slopes and curvature in the cross‐sectional plots of the SAXS data. This indicate the coexistence of junction zones differing in multiplicity characterized by shifting the distribution towards larger multiplicity either for increasing FG or [Ca2+]. The present finding of junction zone formation by lateral condensation of α‐L‐GulA sequences depending on the composition of alginate and Ca‐concentration are significant extensions of the “egg‐box” model that correlate the sequential arrangement of α‐L‐GulA and β‐D‐ManA in alginate to the structure of the junction zones in the Ca‐alginate gels.
Solubilization of oligosaccharides into chloroform by their incorporation into polystyrene as pendant groups
Authors: Kobayashi Kazukiyo , Kamiya Shoko 
Published: March 2011

AbstractSolubilization of hydrophilic saccharide chains into organic solvents has been attempted by incorporating saccharide‐substituted styrene unit into polystyrene main chain. Lactose‐, maltopentaose, and amylose‐substituted styrene monomers were copolymerized with styrene. Resulting chloroform‐soluble copolymers were characterized, and structural formation was investigated. Copolymers of lactose‐substituted styrene and maltopentaose‐substituted styrene with styrene were dissolved into chloroform. The chloroform‐soluble polymers contained about 12 disaccharide lactose chains or 1.7 maltopentaose chains as the pendant groups in one polystyrene molecule. Chloroform‐insoluble methyl orange was dissolved into chloroform with the help of chloroform‐soluble polystyrene having some saccharide chains. On the other hand, when an amylose‐substituted styrene unit was inserted in a polystyrene chain, the resulting polymer became insoluble into chloroform. Amylose polysaccharide of DPn = ∼24 was not dissolved into chloroform by this method.