bluuebunny/crossref_metadata_2025_split huggingface dataset:
Grafting of amino groups on polybutadiene by hydrosilylation
Authors: Hazziza‐Laskar Judith , Hélary Gérard , Sauvet Georges 
Published: March 2011

AbstractHydrosilylation catalyzed by hexachloroplatinic acid was used to introduce tertiary amino groups in an hydroxytelechelic polybutadiene. Kinetics and mechanisms were investigated. At low silane concentration, the reaction is first‐order in Pt, second‐order in silane and zero‐order in vinylic double bonds. The apparent rate constant is inversely proportional to the concentration of amino groups (inhibitory effect). At high silane concentration, very sharp acceleration periods are observed and explained by a transformation of a weakly active Pt(II) catalyst into a more active Pt(O) compound.
New filaments and fibres of polyetherimide
Authors: Böhringer B. , Schilo D. , Birkenfeld W. , Odenthal W. 
Published: March 2011

AbstractPolyetherimide is a high‐performance polymer which can be extruded to fibres and filaments. The threads are amorphous and have a smooth and closed surface. The material can be drawn and subsequently processed to textiles in the conventional way. Filaments of polyetherimide are flame‐resistant. The chemical resistance of polyetherimide is good; the polymer is particularly resistant to diluted acids, salts and oxidants.
Nonlinear viscoelastic stress relaxation behaviour of aramid fibers
Authors: Wortmann F.‐J. , Schulz K. 
Published: March 2011

AbstractWith the increasing demand for polymers as materials for construction, the exact analysis of their mechanical properties in general and of their viscoelastic performance in specific becomes of increasing importance. An analytical model is introduced which enables to systematically describe the influence of strain on the stress relaxation performance of Kevlar®, Nomex®, and Technora®. The analysis is based on a two‐phase model, comprised of an elastic and a viscoelastic contribution and a shape‐invariate relaxation function. The change of the phase moduli and of the mean relaxation times with strain is documented for the three aramid fibers and discussed with respect to their morphological structures.
Silicate coupling layer for metal to polymer adhesion improvement: Physical‐chemical fundamentals and technological importance
Authors: Tiller H.‐J. , Göbel R. , Gutmann N. 
Published: March 2011

AbstractSilicated metal surfaces may improve the adhesion of polymers to metal surfaces. Two different methods of silicate formation ‐ a flame pyrolysis of orthosilicates and a sol‐gel coating based on a CrIII‐ doped SiO2‐sol ‐ are proposed. The coupling of the SiO2‐layer on the metal oxide surface, their structure and morphology and, the effect of the silane coupling agent on the adhesion mechanism are discussed. The formation of stable and durable compounds is proved by shear strength measurements and SEM analysis of the interface after boiling tests. Additionally, the adhesion of glued joints between glasses, ceramics and metals is also improved by this method.
Effect of the polymer matrix on the properties of advanced composites
Authors: Altstädt Volker 
Published: March 2011

AbstractThe relationships discussed here clearly show that for the development of composite materials a multidisciplinary approach encompassing polymer chemistry, physics, engineering and material science is necessary. The complex composition of fiber reinforced polymeric composite materials, involving the synergistic interplay of individual components, requires new methods for the development of materials, which are not solely based on the formulation chemistry of the components.In the future, resistance against the application of advanced composites must be reduced, by gaining more confidence in the performance of this new class of materials with a fundamental understanding of their properties and potential. It will thus be possible to abolish unreasonable test methods and to use design characteristics which take maximum advantage of this material class.
Combination of glass fibres and minerals in polyamides
Authors: Hewel M. , Sun F. 
Published: March 2011

AbstractPolyamides reinforced with glass fibres are characterised by high values for modulus of elasticity and notched impact strength but also have the negative properties of rough surfaces and anisotropy ‐ particularly anisotropic shrinkage. Mineral‐filled polyamides have good surface properties, are isotropic and have high impact strength, however, the elasticity modulus is only slightly better than for normal polyamides and notched impact strength values are relatively low.Through a combination of glass fibres and mineral filler, surface properties can be improved and anisotropy reduced. In order to achieve the optimum mechanical properties a range of 0 ‐ 50 wt.‐% glass fibre content and 0 ‐ 40 wt.‐% mineral content was systematically examined using statistically designed experiments. This investigation showed the relationship between the “Responses”, surface appearance, shrinkage, modulus of elasticity, impact strength and tensile properties and the “variables”, glass fibre and mineral content. Optimal products, based on the model functions, can be chosen in this way.
Dynamics and deformation behaviour in non‐hydrogen bonded model urethanes under heat and stress as studied by dielectric and infrared spectroscopy
Authors: Boese D. , Eisenbach C. D. , Fischer E. W. , Hayen H. , Nefzger H. , Planer‐Kühne G. , Reynolds N. , Spiess H. W. 
Published: March 2011

AbstractA model polyether‐urethane with monodisperse N‐alkyl polyurethane hard segment has been investigated by differential scanning calorimetry, dielectric spectroscopy and infrared spectroscopy. The temperature dependent changes in the enthalpic and dielectric properties have been correlated with specific molecular motions and transition processes in the hard and soft phase. The orientation of the hard and soft segments under uniaxial stress changes with the strain and mechanisms for the orientation and deformation behaviour have been proposed. Effects of the thermal history of the sample on the properties have been discussed as well.
Liquid‐crystalline silsesquioxanes
Authors: Kreuzer Franz‐Heinrich , Maurer Robert , Spes Peter 
Published: March 2011

AbstractLiquid‐crystalline silsesquioxanes were synthesized by combining mesogens with spherical silsesquioxanes. Most of the synthesized compounds exhibit smectic phases. Lateral connection of a mesogen results in a nematic phase. All phases are optical uniaxial positive, i.e. calamitic structures are favoured. LC‐silsesquioxanes represent a new group of liquid‐crystalline side‐chain polymers with backbones ranging from centrosymmetric cage like structures of siloxanes or heterosiloxanes to linear ladder structures. They can be considered as the link between the linear side‐chain polymers and surface treated silica or quartz.
Thermotropic poly(urethane)s from nematic diisocyanates
Authors: Mormann Werner , Benadda Saria 
Published: March 2011

AbstractA number of novel triad diesterdiisocyanates with a core of either a (substituted) hydroquinonedibenzoate or diphenyl terephthalate are described. Due to their higher aspect ratio (length of mesogenic core) with regard to diad esterdiisocyanates, thermotropic diurethanes and hard segment type poly(urethane)s are obtained and characterized with regard to their phase behaviour. The influence of the structure of the diisocyanate as well as that of the diol is discussed.
Structure, dynamics and phase separation in liquid crystalline polymers, block copolymers and blends as revealed by solid state NMR spectroscopy
Authors: Spiess H. W. 
Published: March 2011

AbstractA short survey is given of possibilities solid state NMR techniques offer for the study of functional polymers. Three examples are described explicitly, photoinduced reorientation of liquid crystalline polymers considered for information storage, phase separation and the mobility in the interfacial regions in segmented model polyurethanes composed of hard and soft segments and determination of domain sizes in incompatible polymer blends.
Time‐resolved, static light scattering: New possibilities in polymer characterization
Authors: Becker A. , Schmidt M. 
Published: March 2011

AbstractWe have developed a highly sensitive, multi‐angle, static light scattering (TRSLS = time resolved static light scattering) instrument, which measures the angular dependent Rayleigh scattering intensity of solutions simultaneously at 38 angles within approximately one second. It is thus suitable as a quick and easy to use static light scattering device for routine polymer and colloid characterization. The time resolution allows the kinetics of many systems to be investigated down to a second time scale, such as polymerization kinetics of linear, branched and crosslinked polymer structures, thermoreversible gelation, growth of colloidal particles, structural changes in micellar systems, etc.
Molecular structure and dynamics in monolayers of long chain alkanes and alkyl‐derivatives
Authors: Rabe Jürgen P. , Buchholz Stefan 
Published: March 2011

AbstractLong chain alkanes (C34H70 and C50H102), a fatty acid (C17H35COOH) and an alkyl‐substituted triiodobenzoate (I3H2C6COOC18H37) have been adsorbed at the interface between organic solutions and the basal plane of graphite. In‐situ scanning tunneling microscopy (STM) has been employed to investigate their structure and dynamics on the scale of 10 pm and 1 ms or longer. All adsorbates form two‐dimensional polycrystals. The molecules tend to organize in lamellae with the extended alkyl chains oriented parallel to a lattice axis within the basal plane of graphite. The n‐alkane chains pack in a lattice commensurate with the graphite lattice and the carbon skeleton planes approximately perpendicular to the substrate. Due to the additional space required by a carboxyl end group the alkyl lattice in the fatty acid is incommensurate with the substrate and the carbon skeleton planes lie approximately parallel to the surface. In the triiodobenzoate the headgroup takes the space of about two alkyl chains resulting in an interdigitated packing.
Main‐chain side‐chain liquid crystal polymer blends for improved physical properties
Authors: Cheng Wei‐Ming , Rasoul Husam A. A. , Stackman Robert W. 
Published: March 2011

AbstractPrevious work has demonstrated that compatible blends of main‐chain liquid crystal polymers (LCP) with side‐chain LCP's can be prepared. The present work was carried out to extend the scope and application of this finding to liquid crystal polyesters, similar to commercially available LCP's and to demonstrate the effect of the blend composition upon the physical and mechanical properties. A series of melt‐processable main‐chain polyesters was prepared as well as a series of acrylic polymers and copolymers which possess a side‐chain mesogenic unit, similar to that of the main‐chain LCP's. While the results of the blending studies of these high molecular weight materials were somewhat ambiguous as to compatibility, there are strong indications that the presence of the side‐chain mesogen containing polymers does result in an improvement in the overall mechanical properties of the main‐chain LCP.
Miscibility windows for poly(styrene‐co‐vinyl phenol) blends with poly(alkyl methacrylate)s: Further comparisons of theoretical predictions to FTIR experimental data
Authors: Xu Yun , Painter Paul C. , Coleman Michael M. 
Published: March 2011

AbstractWe report the results of theoretical and experimental studies of styrene‐co‐vinyl phenol (STVPh) copolymer blends with poly(n‐octyl methacrylate) (POMA) and poly(n‐decyl methacrylate) (PDMA). This work is a natural extension to our recently reported studies of the phase behavior of analogous STVPh blends with poly(n‐butyl methacrylate) (PBMA) and poly(n‐hexyl methacrylate) (PHMA) where we employed an association model together with parameters obtained from studies of miscible homopolymer blends. The theoretically calculated miscibility maps for STVPh copolymer blends with the homologous series of poly(n‐alkyl methacrylates) (PAMA) are in fine agreement with experiment.
Computer simulation of the chemical properties of copolymers
Authors: Spurling T. H. , Deady M. , Krstina J. , Moad G. 
Published: March 2011

AbstractA new method for modelling polymerization kinetics is described in which numerical integration is used to provide the time scale for the polymerization experiment and Monte Carlo methods are employed to calculate the instantaneous molecular weight distribution, detailed chain composition, and chemical heterogeneity of the polymer as a function of time/conversion. The method has been applied in simulations of styrene‐methyl methacrylate copolymerization and styrene‐hydroxyethyl acrylate‐butyl acrylate terpolymerization.
Multifunctional acrylate monomers, dimers and oligomers: Applications from contact lenses to wood‐polymer composites
Authors: Mathias Lon J. , Kusefoglu Selim H. , Kress Albert O. , Lee Soo , Wright J. Randolph , Culberson Doris A. , Warren Stephan C. , Warren R. Michael , Huang Sophia , Lopez David R. , Ingram J. Eric , Dickerson Carroll W. , Jeno Muthiah , Halley Robert J. , Colletti Ronald F. , Cei Gustavo , Geiger C. Cecil 
Published: March 2011

AbstractThe synthesis of various esters of α‐hydroxymethylacrylate are summarized along with a brief description of their properties and polymerizability. Polymer characterization is given, including thermal behavior, solubility and spectroscopic properties. Derivatives of the acrylates are generated through reaction of the alcohol group to give halides, esters, ethers, and ether dimers. The last, along with additional multifunctional acrylates generated through the chemistry inherent in the synthetic approach, allow formation of a number of cyclopolymers, Michael polyadducts, and crosslinked systems.
New functional polymers, blocks and thermoplastic elastomers by living carbocationic polymerization
Authors: Kennedy Joseph P. 
Published: March 2011

AbstractSystematic fundamental investigations have recently led to the discovery of living carbocationic polymerizations which in turn resulted in a variety of materials, specifically macromonomers, end‐functionalized (telechelic) polymers, block copolymers and thermoplastic elastomers. This lecture will mainly focus on the synthesis principles used for the synthesis of well‐defined telechelics such as allyl‐terminated linear or three‐arm radial polyisobutylenes, and polyisobutylene‐based thermoplastic elastomers, such as poly(styrene‐b‐isobutylene‐b‐styrene) (PSt‐PIB‐PSt), and poly(indene‐b‐isobutylene‐b‐indene) (PIn‐PIB‐PIn).
Miscibility maps for copolymer ‐ copolymer blends: A comparison of theoretical predictions to experimental studies of poly(styrene‐co‐vinyl phenol) blends with poly(ethylene‐co‐methyl acrylate)
Authors: Coleman Michael M. , Xu Yun , Painter Paul C. , Harrell Jerald R. 
Published: March 2011

AbstractWe report the results of theoretical and experimental studies of random amorphous styrene‐co‐vinyl phenol (STVPh) copolymer blends with ethylene‐co‐methyl acrylate (EMA). This work is a natural extension to our recently reported studies of the phase behavior of analogous STVPh blends with an homologous series of poly(n‐alkyl methacrylate) homopolymers, where we employed an association model together with parameters obtained from studies of miscible homopolymer blends. Here we emphasize that there is no conceptual difference between the average chemical repeat of a random copolymer and that of an analogous repeat unit of a homopolymer containing the same number and type of functional groups. The theoretically calculated miscibility maps for STVPh ‐ EMA copolymer blends are in outstanding agreement with experiment.
Miscibility maps for copolymer ‐ copolymer blends: A comparison of theoretical predictions to experimental studies of poly(styrene‐co‐vinyl phenol) blends with poly(ethylene‐co‐vinyl acetate)
Authors: Xu Yun , Painter Paul C. , Coleman Michael M. 
Published: March 2011

AbstractWe report the results of theoretical and experimental studies of random amorphous styrene‐co‐vinylphenol (STVPh) copolymer blends with ethylene‐co‐vinyl acetate (EVA). This work complements the study presented in the previous paper published in this journal, pertaining to the phase behavior of analogous STVPh blends with ethylene‐co‐methyl acrylate (EMA) copolymers. Poly(vinyl acetate) (PVAc) and poly(methyl acrylate) (PMA) contain the same number and type of functional groups in their respective repeat units, (the only difference being that the ester group is reversed), and the solubility parameters of PVAc and PMA calculated from our non‐hydrogen bonded group contributions are equivalent.Furthermore, the equilibrium constants describing the inter‐association of phenolic hydroxyls to acetate or acrylate carbonyl groups are comparable. Accordingly, miscibility maps for STVPh ‐ EMA and STVPh ‐ EVA copolymer blends calculated from our association model should be virtually identical and this is confirmed by our experimental studies.
FTIR studies of polar interactions in polymer blends
Authors: Braun D. , Eidam N. , Leiß D. 
Published: March 2011

AbstractSpecific interactions in binary blends of poly(vinyl chloride) (PVC) with ethylene–vinyl acetate copolymers (EVA) and ethylene‐methyl acrylate copolymers (EMA) were investigated by observation of band shifts of the carbonyl absorption using ATR‐FTIR spectroscopy at variable temperature. Blends of PVC with EVA and EMA could be prepared as heterogeneous, homogeneous or metastable homogeneous mixtures, depending on the copolymer composition. The miscible systems as well as the heterogeneous ones showed only very small or no band shifts. The metastable blends exhibited shifts of several wave numbers to lower values, which vanished at higher temperatures as the blends demixed. Strong interactions in the metastable blends could be related to good impact properties of the corresponding two‐phase systems.
Near‐infrared spectroscopy of polymers
Authors: Siesler H. W. 
Published: March 2011

AbstractAlthough near–infrared (NIR) spectroscopy has been used over many decades for the – primarily quantitative – analysis of polymers containing OH–, NH– and CH–functionalities (e.g. determination of OH–number, water content and residual carbon–carbon double–bonds), it has never been established as a wide–spread analytical and physical tool comparable to other spectroscopic techniques. In the late seventies, however, two new developments have initiated a renaissance of NIR spectroscopy in analytical chemistry. On the one hand, chemo–metric data evaluation techniques have – in combination with diffuse reflection measurements – opened up the possibility of non–destructive, rational multicomponent analysis and identity control of solid polymers with varying morphologies. On the other hand, the introduction of optical light fibres has contributed to an enormous expansion of conventional NIR spectroscopy in terms of remote control. Thus, specific fibre–optic probes allow a separation of the spectrometer and the location of sample measurement over several hundred meters and tremendously alleviate the analysis of toxic and hazardous materials including process and reaction control. Recently, further progress is made by the development of new, rapid‐scan NIR monochromator systems without mechanically moved parts, such as acousto–optic tunable filters. Last, but not least, it should be mentioned, that – although not treated here – the new approach of Fourier–Transform Raman spectroscopy with Nd–YAG laser excitation at 1064 nm is principally also a near–infrared technique.
Fourier ‐ transform infrared ‐ spectrometric investigation of blends of terephthalic polyesters with polycarbonate
Authors: Klee W. , Hummel D. O. 
Published: March 2011

AbstractBlends of polycarbonate (PC) and poly(ethyleneterephthalate) (PET) or poly(butyleneterephthalate) (PBT) heated above the melting temperature of the crystalline component show transesterification reactions. The crystallizability of the resulting system (mixture of copolyesters with homopolymers) decreases with time. Blends of PET and PC loose their crystallizability after 10 ‐ 20 min at 543 K. After that treatment samples with low content of PC have lost the characteristic IR absorptions of PC. Transesterification is faster in blends of PBT and PC: after 3–15 min at 543 K the crystallizability has vanished. After transesterification has reached equilibrium a homogeneous statistical copolymer has developed from the homopolymers.
FT‐IR photoacoustic and x‐ray diffraction study of orientation of an injection‐molded liquid‐crystalline poly(ester‐amide)
Authors: Barres O. , Friedrich C. , Jasse B. , Noël C. 
Published: March 2011

AbstractThe orientation development that takes place during injection molding of liquid‐crystalline polymer (LCP) is analyzed by FT‐IR photoacoustic (PA) spectroscopy and X‐ray diffraction. The LCP used is the commercial Hoechst‐Celanese product Vectra B 900 prepared from 6‐hydroxy‐2‐naphthoïc acid, terephthalic acid and p‐acetoxyacetanilide. The analysis reveals the so‐called skin‐core morphology. The highly oriented skin layer is thought to originate in the advancing melt front where the “fountain flow” dominates. A less oriented transition layer due to the shear flow is located under the skin layer. The core is related to plug flow and has relatively poor orientation.
The destruction‐free analysis of polymers by fourier transform infrared photoacoustic and fourier transform Raman spectroscopy: A comparison
Authors: Grose R. I. , Hvilsted S. , Siesler H. W. 
Published: March 2011

AbstractWith the introduction of rapid–scanning Fourier transform infrared (FTIR) and recently Raman (FT–Raman) spectroscopy, vibrational spectroscopy has been launched into a new era of applications in polymer chemistry and physics. Thus, the increase in sensitivity provided by multiple scanning has led to the breakthrough of new, destruction–free sampling techniques, such as photoacoustic and Raman spectroscopy. This paper provides a comparison between data produced by FTIR photoacoustic and FT–Raman analysis of a range of polymers, and structural information available from both techniques is discussed.
Vibrational spectroscopy of implants
Authors: Afanasieva Natalia , Brame Edward , Korigodsky Alexander , Tupikova Tatiana 
Published: March 2011

AbstractThe results of systematic spectral studies of polymers in ophthalmology are presented. The spectral criteria of selection of intraocular lens (IOL; implants of long service in an organism have been defined for poly(methylphenylsiloxane). Non‐inflammatory implantation of IOL, when the manufacturing of lenses is performed under spectral control at several stages, has been realized. New siloxane–polyurethane block copolymers promising for ophthalmology have been studied and passivated surfaces have been obtained.
1H, 2H and 13C NMR spectra and molecular dynamics of some solid alkylene‐aromatic polyesters
Authors: Kapralova V. M. , Khachaturov A. S. , Koltsov A. I. , Sko‐rokhodov S. S. , Zuev V. V. 
Published: March 2011

AbstractMolecular dynamics of some mesomorphic main–chain alkylene–aromatic polyesters have been investigated by means of NMR spectra of various nuclei over a wide temperature range. In solid polymers regions of different molecular mobilities coexist and their fractions are determined by the sample temperature and thermal history. The sample annealing leads to the growth of rigid fraction. It was found that below the glass transition temperature the only forms of large–scale mobility are the torsional vibrations and flips of para–phenylene groups, while spacer groups are virtually rigid. Above the glass temperature almost all phenylene rings undergo flipping motions and methylene groups of the spacer take part in complicated motions of both anisotropic and isotropic character.