bluuebunny/crossref_metadata_2025_split huggingface dataset:
State of order in blends of poly(butylene terephthalate) with poly(ethylene terephthalate) or polycarbonate
Authors: Wings Norbert , Trafara Gundolf 
Published: March 2011

AbstractBlends of PBT with PET or PC were studied by X‐ray diffraction and DSC for different conditions of crystallization. PBT and PET crystallize very similarly, though they are recognized as partially compatible in the melt. In the PBT/PC blends X‐ray diffraction examinations show crystallization of PC after 4 h of annealing. In the melt, both components are compatible. Tg‐calculations indicate a plasticizing effect. In both kinds of blends, PBT crystallizes faster than PC or PET. Fast crystallization processes were examined by X‐ray diffraction measurements with synchrotron radiation.
Non‐markovian effects in NMR relaxation processes: An application to molecular dynamics in branched and cross‐linked solid polymers
Authors: Denner Paul , Götz Horst , Eichhorn Falk 
Published: March 2011

AbstractThe dynamic of restricted rotatranslation of mobile structural defects along a polymer chain are treated with an equation of motion with a non‐Markovian, stochastic force. The MORI/KUBO/ZWANZIG representation gives a stochastic process with a memory where the loss of correlation is dependend on the restriction of diffusional motion of defects. The influence of crosslinks and branchings of the polymer chains on the molecular dynamics are discussed.The analytical spectral densities of ω−‐α‐type characterized by the fractal dimensions of the relevant processes in the different polymeric systems, e. g. cis‐polybutadiene, cis‐polyisoprene, styrene‐butadiene‐rubber, high density and linear low density polyethylenes, are compared with the observed NMR data.
Kinetic study of the template polymerization of N‐vinyl‐2‐pyrrolidone in the presence of poly(acrylic acid) by infrared spectroscopy; effect of template molecular weight on the rate of the reaction
Authors: Al‐Alawi Saeed , Al‐Mutawah Jameela I. 
Published: March 2011

AbstractThe kinetics of template polymerization of N–vinyl–2–pyrrolidone in the presence of poly(acrylic acid) (PAA) was followed by Fourier transform infrared (FT–IR) spectroscopy. It was found that the intensity of the carbonyl stretch increased with time. The results were used to draw the rate curve for the template system by plotting the intensity of the carbonyl group band against time. It was found that the rate of polymerization increased as the molecular weight of PAA increased. The above results were in agreement with the rate curve obtained by bromometric titration for the same system.
Spectroscopic investigations on polymeric core‐shell systems
Authors: Hergeth Wolf‐Dieter , Lange Jens 
Published: March 2011

AbstractInfrared and Raman spectra of polymers obtained by a two–stage emulsion polymerization process were measured. The spectra were analyzed in context with other experiments to obtain information on the internal structure of the polymer particles. In the case of incompatible polymers, the extension of the interfacial layer between both polymers can be derived.
On the molecular mechanism of clouding in aqueous solution of poly(oxyethylene)‐poly(oxypropylene)‐poly(oxyethylene) triblock copolymers
Authors: Hergeth W.‐D. , Alig I. , Lange J. , Lochmann J. R. , Scherzer T. , Wartewig S. 
Published: March 2011

AbstractThe physical aspects of the clouding phenomenon in the aqueous solution of a poly(oxyethylene)(POE) – poly(oxypropylene)(POP) – poly(oxyethylene)(POE) triblock copolymer were investigated by applying various experimental methods: viscometry, ultrasonic technique, light scattering, infrared and Raman spectroscopy. The ultrasonic absorption studies hint at a critical behaviour. In order to understand the spectroscopic findings, conformational energies of model POE molecules as well as interaction energies between oxyethylene (OE) units and water molecules were calculated by the use of the quantum chemical PCILO method. It is suggested that the clouding is connected with conformational changes of POE segments.
Theories in polymer science ‐ helpful or inhibiting?
Authors: Solomon David H. , Jones Stephen L. 
Published: March 2011

AbstractTheories in polymer science play an important role in how experiments are designed and results interpreted. Three areas of polymer chemistry are focussed on: step growth polymerization, particularly predictions of equal reactivity of functional groups; free radical chain polymerization with emphasis on structural irregularities and the consequences of these structures for previous theories; free radical copolymerization and the many models at present under discussion aimed at providing a theoretical basis for predicting the outcome of such copolymerization. The question of whether or not we as polymer chemists have been helped or hindered by theory is addressed.
How to increase the service temperature of polystyrene
Authors: Maul J. , Meyer H. H. 
Published: March 2011

AbstractIn this overview we describe more recent attempts to raise that temperature range of polymeric systems containing styrene as the major starting monomer in which an article will loose dimensional stability under specified conditions.A search in the literature, both in journals and patent applications, over the last five years reveals a wealth of possibilities to perform this task. However, only a few of these have reached the commercial status, mostly due to reasons.
Ordering processes in the 2,6‐hydroxynaphthoic acid (HNA) rich copolyesters of p‐hydroxybenzoic acid and HNA
Authors: Kachidza J. , Serpe G. , Economy J. 
Published: March 2011

AbstractThe nature of the microstructure of several copolyesters of p‐hydroxybenzoic acid (HBA) and 2,6‐hydroxynaphthoic acid (HNA) with compositions of 20/80, 24/76, and 30/70 was studied. Annealing the compositions at 50–80 °C below the crystal nematic transition resulted in a physical ordering process, whereas heating the polymers at the crystal nematic transition resulted in a more highly ordered phase. The ordered phases could be randomized by heating to a temperature at or above the transition of the more highly ordered phase.
Sensitive resist systems based on acid‐catalyzed polymer reactions
Authors: Ito Hiroshi , England William P. , Ueda Mitsuru 
Published: March 2011

AbstractAcid‐catalyzed polymer reactions have been successfully utilized in the design of chemical amplification resist systems for semiconductor manufacturing. In this paper are described preparation and acid‐catalyzed depolymerization reactions of α‐substituted polystyrenes.
Design and architecture of macromolecular structures
Authors: Vogl Otto , Kratky Christoph , Simonsick William J. , Xi Fu , Hatada K. 
Published: March 2011

AbstractMacromolecules exist in a variety of molecular and super‐molecular arrangements. Among these are random coils and regular polymer structures with extended chain, some with lamellar and spherulitic morphology and rigid rod structures. An important macromolecular arrangement is the helical structure. For the control of the synthesis of the perfect helix, the stereochemistry of the oligomerization was studied; the best example for this investigation was found to be the oligomerization of the trihaloacetaldehydes, e.g. fluoral, chloral and bromal.
Ultra‐thin films of conjugated polymers for opto‐electronic applications
Authors: Ogata Naoya 
Published: March 2011

AbstractUltra‐thin films of precursor polymers for poly(benzimidazole) (PBI), poly(benzoxazole) (PBO), or poly(benzthiazole) (PBT) were formed at air/water interface by spreading monomers and then polymerizing on the water surface. These thin films could be deposited onto appropriate substrates such as quartz by using the Langmuir‐Blodgett (LB) method of horizontal lifting. Moreover, the heat treatment of the built‐up films of the precursor polymers transformed the films into corresponding PBI, PBO, or PBT, which were high‐temperature polymers. The resulting films had uniform and controllable thickness. Electronic and opto‐electronic properties of these thin films were evaluated in terms of electric conductivities and nonlinear optical properties.
Copolymers of 1.5‐dioxepan‐2‐one and L‐ or D,L‐dilactide ‐ synthesis and characterization
Authors: Albertsson Ann‐Christine , Löfgren Anders 
Published: March 2011

AbstractThe copolymerization of 1,5‐dioxepan‐2‐one (DXO) with L‐ or D,L‐dilactide in bulk has been studied, using stannous‐2‐ethylhexanoate as the initiator.The copolymers were characterized using 1H‐ and 13C‐NMR spectroscopy, and DSC‐analysis. The molecular weight of the copolymers was measured by SEC, viscometry and light‐scattering techniques.The reactivity ratios of the copolymer system were calculated using the Kelen‐Tüdos method to be r1 (DXO)=0,1 and r2 (dilactide)=10.No racemization seems to have taken place during polymerization as shown by the absence of stereochemical splittings in the 13C‐NMR spectra of the L‐dilactide homopolymer. The ability of the L‐LA/DXO copolymer to crystallize seems to be retained despite substantial amounts of 1,5‐dioxepan‐2‐one in the composition. 1H‐ and 13C‐NMR spectra indicate ring‐opening of the monomers by alkyloxygen cleavage.
Synthesis and properties of polyampholytes prepared in microemulsions
Authors: Corpart Jean‐Marc , Selb Joseph , Candau Françoise 
Published: March 2011

AbstractA series of polyampholytes of sodium 2‐acrylamido‐2‐methylpropanesulfonate (NaAMPS) and 2‐(methacryloyloxy)ethyltrimethylammonium chloride (MADQUAT) has been synthesized by polymerization in microemulsions. The reaction products are stable inverse latexes consisting of high molecular weight copolymers entrapped in water droplets of small size (d % 80 nm) and dispersed in an isoparaffinic oil. The optimization of the formulation was by a selection procedure based on the hydrophile‐lipophile balance of the emulsifiers and solubility parameters of the different components. Both ionomers play an important role in the formulation owing to their amphiphilic and electrolyte characters. Reactivity parameter studies yield rA and rM values of 0.81 and 1.97 for NaAMPS and MADQUAT, respectively. The properties of polyampholytes in pure water and in salt solutions were investigated by turbidimetry and viscometry experiments. The results are compared with the recently developed theory of Higgs and Joanny (J. Chem. Phys. 94, 1543 (1991)).
ESCA studies of charge transfer interactions in electroactive polymers
Authors: Kang E. T. , Neoh K. G. , Tan K. L. 
Published: March 2011

AbstractX‐ray photoelectron spectroscopy (XPS) data suggest that proton modifications of nitrogens in polypyrrole (PPY) give rise to a number of intrinsic redox states analogous to those observed in polyaniline (PAN). The behavior of the corresponding oxidation states in both polymers towards oxidation/reduction, deprotonation/reprotonation or charge transfer (CT) interactions are grossly similar. For the thiophene polymers, such as the poly(2,2′‐bithiophene) (PBT) complexes and poly(3‐methylthiophene) (P3MT) complexes, XPS results reveals the simultaneous presence of neutral and polarized (or partially charged) species in both carbon and sulfur. The relative amounts of the neutral and polarized species vary in accordance with the oxidation level of the polymer. These results suggest that each dopant anion is associated with a thiophenium ion in the polymer chain. Substantially lower extent of CT is observed in the complexes involving photoconductive substituted polyacetylenes, such as polyphenylacetylene (PPA) and poly[[o‐(trimethylsilyl)phenyl] acetylene] or poly(o‐Me3SiPA).
Copolymerization of polar and non‐polar monomers in direct and inverse emulsion systems
Authors: Bartoň Jaroslav 
Published: March 2011

AbstractSome problems connected with the use of monomers with different solubilities in water and oil phases for copolymerization in direct and inverse (micro)emulsions are discussed. We have shown that by choosing appropriate model systems which can simulate specific effects connected with the transfer of reactants between various phases and swelling ability of polymer particles, one can contribute to the answering the questions of the propagation locus (loci) of copolymerization and of its (their) history during emulsion copolymerization as well as to recognize the effect of the nature of the interlayer in the inverse (micro)emulsion system in relation to the kinetics and mechanism of the copolymerization process and structure of the copolymer formed. The method was demonstrated on the examples of seeded methyl methacrylate emulsion polymerization, of the emulsion copolymerization of styrene and divinylbenzene and of the inverse (micro)emulsion copolymerization of acrylamide and methyl methacrylate and/or acrylamide and styrene.
Applications of ROMP in the synthesis of new materials
Authors: Feast W. J. 
Published: March 2011

AbstractRing opening metathesis polymerisation (ROMP) is a relatively recent addition to the armoury of synthetic methods available to polymer chemists. Until recently it has found only a fairly limited exploitation in the manufacture of speciality elastomers. This review briefly describes the development of ROMP and indicates some of its industrial applications. The main emphasis, however, will be on work carried out in the Durham Laboratories during the last ten years in applying ROMP to the synthesis of new polymeric materials.
The characterization of polymer interfaces by fluorescence decay measurements
Authors: Winnik Mitchell A. 
Published: March 2011

AbstractFluorescence decay measurements of energy transfer between donor (D) and acceptor (A) chromophores covalently attached to polymers can provide rich information about a polymer system. Here we use these techniques to study two quite different polymer phenomena. The first involves the diffusion of polymer molecules across the interfaces created during latex film formation. We are able to determine diffusion coefficients for this process. The second involves the phase separation which occurs in mixtures of homopolymers and graft copolymers. Here we are able to show that where a component of the graft is highly incompatible with the homopolymer matrix, interconnected domains of very small size can form. Under certain circumstances fluorescence decay measurements in conjunction with the recent model for “energy transfer in restricted geometrics” can be used to map out the size and shape of these domains.
Synthesis, structure and properties of chiral polymers from ring‐opening polymerization
Authors: Spassky Nicolas 
Published: March 2011

AbstractDifferent synthetic methods for the preparation of polymers by ring‐opening polymerization with various distribution of enantiomeric units in the macromolecular chain are available. The structure of prepared polymers is determined by 1H and 13C NMR, X‐rays diffraction, ORD and CD. Physicochemical and mechanical properties may strongly depend upon the enantiomeric composition of the polymer chain. In several cases racemate mixtures of polyenantiomers form stereocomplexes with enhanced thermal properties.
The lighter side of darwinism? Photoselection of the species: Applications of luminescence anisotropy measurements to the study of polymer relaxation
Authors: Soutar Ian 
Published: March 2011

AbstractThe application of luminescence anisotropy techniques to the study of polymer systems is discussed. Investigations of polymer relaxation both in fluid solutions and the solid state are addressed. Particular attention has been paid to considerations of reliable means of information retrieval from experimental time‐resolved anisotropy data.
Experimental problems and recent results in polymer melt rheometry
Authors: Meissner Joachim 
Published: March 2011

AbstractRecent developments helped to solve some experimental problems in polymer melt rheometry: By a stability test one can find out whether under test conditions the individual polymer melt is sufficiently long stable. For melts with long relaxation times, an incomplete creep‐test followed by recovery is proposed to determine the linear viscoelastic material functions. In a cone‐and‐plate rheometer, a very constant heating system and the separation of the plate into a central disk and an outer ring allow us to measure the two normal stress differences in viscometric flows also at higher temperatures. For a commercial LCP, a special sample preparation technique is reported. Melt elongation followed by recovery in combination with morphological studies are presented for a polymer blend (PMMA/PS). From the combination of recovery after melt extension and morphology the interface tension between the melts of PS and PMMA can be determined.
Rheology of anisotropic homogeneous and heterogeneous media
Authors: Kulichikhin V. , Polushkin E. , Antipov E. , Shumskii V. , Volkov V. , Plate N. 
Published: March 2011

AbstractOne of the main features of lyotropic and thermotropic liquid‐crystalline (LC) polymers is non‐homogeneity of their structure, which is reflected in their rheological properties. Relationships between some kinds of heterogeneities, viz. dynamic textures, isotropic‐anisotropic biphasic region, superposition of different types of crystalline and mesophase structures, framework formed by fillers and rheological characteristics have been analyzed.
Predictions of a recently proposed non‐markovian model for polymer melts and concentrated solutions
Authors: Schieber Jay D. , Petruccione Francesco 
Published: March 2011

AbstractSeveral predictions for a recently proposed mesoscopic model for polymer melts and concentrated solutions is presented. It is a single Kramers chain model in which elementary motions of the Orwoll‐Stockmayer type are allowed. However, for this model, the bead jumps are no longer given by a Markovian probability, but rather are described by a fractal “waiting‐time” distribution function, with a single adjustable parameter β, which describes the long‐time behavior of the distribution: ∼ 1/t1+β. We find that the model predicts D ∼ 1/N2 and η0 ∼ N3.4 for β ≈︁ 1.4, where N is the degree of polymerization. The generalized model predicts that the relaxation spectrum has a plateau regime whose height is independent of N, but whose width is strongly N dependent, in agreement with experiment. The model also predicts that rings will diffuse somewhat more slowly than linear chains of the same molecular weight (about 80% as fast), with the same scaling dependence on N as linear chains, also in agreement with preliminary data.
Plastics waste management in Europe
Authors: Mader Fred W. 
Published: March 2011

AbstractEnvironmental concern about waste problems and regulatory measures from the governments have increased during the last decade. Plastics waste management has become a major strategic issue for the European plastics industry.A statistical study provides data on plastics consumption, post‐users plastics waste arisings based on a life‐time analysis and plastics recovery in the year 1989. An end‐use sectorial split‐up into sectors like municipal solid waste, automotive waste, agricultural waste, construction, as well as large distribution waste, will serve as a base for an integrated plastics waste management concept including recycling of mono‐material and co‐mingled waste, chemical recycling, energy recovery and landfill.An overview gives examples for ongoing plastics recycling activities in Western Europe and an outlook to the year 2000 is presented.
Current of plastic waste recycling technologies and their prospects in Japan
Authors: Iijima Rinzo 
Published: March 2011

AbstractIn Japan, full‐scale waste plastic recycling business started around 1970. Since then, in parallel with the efforts to develop new uses of recycled products, remarkable progress has also been made in recycling/molding technologies. The most popular recycling/molding technologies applicable to thermoplastics are of melt‐and‐mold type. This presentation discusses the technologies in their present situations, economics and existing disadvantages. The quality standards are set for some recycled products, the relations among recycling technologies, products' physical properties, and quality standards. Among others, explanations are given of waste‐derived solid fuel manufacturing technologies, incineration technologies paired with thermal energy recovery currently available.
Separation technology of used polymers
Authors: Fleming Richard A. 
Published: March 2011

AbstractThe technology of separating plastics from the municipal waste stream for reuse is reviewed, with emphasis on the key role played by the bottle sorting step. Experience gained in the first year's operation of two large commercial recycling plants provides a better understanding of practical problems encountered, their relative importance, and technical advances needed for improved operation. It is concluded that purity of feedstock and processing rate are two critical independent variables requiring technical and business understanding and management. Hypothetical examples illustrate the interplay of these with dependent variables of yield and sorting cost.
Technology available for recycling agricultural mulch film
Authors: Llop C. , Pérez A. 
Published: March 2011

AbstractPlastic films are used for mulching of cotton in the Seville area of Spain. A programme to recycle this type of mulch film was initiated. The different aspects studied were the collection system, the recycling technology and the applications of the recycled material.The long strips of films made transportation difficult. Size reduction and washing were found to be the most critical steps in the recycle process. The reason for this were the high toughness of the film on the one hand and the high level of soil contamination on the other hand. This soil contained up to 3% of iron, a polyethylene prodegradant.
Separation of poly (vinyl chloride) from poly(ethylene terephthalate) and other plastics using automatic sortation devices
Authors: Gottesman Roy T. 
Published: March 2011

AbstractWhile most poly(vinyl chloride) (PVC) produced in the United States is used in the manufacture of durable building products, emphasis recently has been directed at recovery of PVC from post‐consumer disposable items such as bottles, rigid containers and rigid film. Manual sortation involving visual inspection for either the characteristic blow molding scar or code marking is at best only 90% accurate. Recent activity has focused on development of automatic sortation based on recognition of the chlorine atom which serves as a “fingerprint” for identifying PVC. Two separate technologies for sortation of such packaging are discussed in this paper ‐ the first involves X‐ray fluorescence, the second utilizes electromagnetic radiation absorption.
Radlite™: A new technology for comingled plastics
Authors: Shenian Popkin 
Published: March 2011

AbstractWhen applied to the problem of recycling plastics, modified paper‐making technology yields exciting and novel new materials and products with interesting and useful properties. Radlite™ technology is based on paper‐making technology. When feed streams consist of multi‐component recycle thermoplastics and reinforcing materials such as glass fibers, composite materials are produced. A brief description of the essential elements of this process technology will be presented, along with a mechanistic view of compatibility among dissimilar polymers, some comparative materials property data and several examples of possible end use applications of commercial interest.