bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of thiazole polymers for thermally stable plastics
Authors: Sheehan W. C. 
Published: December 2004

AbstractSixteen polymers containing thiazole and aromatic rings in the polymer chain were prepared and investigated for the production of fibers and films that would be useful up to about 500°C. None of these polymers was completely satisfactory. Some of the polymers gave tough fibers and films, but they had relatively low melting points (<300°C). Other polymers did not melt below 500°C, but they did not have good fiber and film forming properties because of their low molecular weights. Fibers and films of one of the polymers (polytetramethylenephenylenethiazole) were prepared, and their physical properties, hydrolytic stabilites under acid and alkaline conditions, and resistence to ultraviolet and gamma radiations were determined.
The phenomenon of draw resonance in polymeric melts. Part I—qualitative view
Authors: Bergonzoni A. , DiCresce A. J. 
Published: December 2004

AbstractWhen a thermoplastic shape is extruded and drawn into a quenching medium and the drawing speed increases continuously, the cross‐sectional extrudate area decreases. At a critical take‐up speed, a cyclic gauge pulsation begins, becoming more pronounced with increasing drawing speed until the extrudate eventually breaks at the air‐coolant in terface. This phenomenon, “draw resonance,” originates in the air gap and is independent of any melt fracture phenomena. Correlations show increasing pulsation severity with increases in speed ratio, air gap, viscosity‐average molecular weight, and decreasing melt temperatures. Draw resonance occurs with polypropylene and various types of polyethylene and polystyrene. Ribbon‐type and round‐hole dies give equivalent results. A semi‐quantitative theory is advanced is explain these phenomena in terms of thermodynamic relationships and basic molecular properties.
Azelaaldehydic acid ester‐acetal derivatives as plasticizers for poly(vinyl chloride)
Authors: Pryde E. H. , Moore D. J. , Cowan J. C. , Palm W. E. , Witnauer L. P. 
Published: December 2004

AbstractCertain ester‐acetal derivatives of azelaaldehydic acid have been evaluated as a new type of plasticizer of PVC. In gerneral, these compouonds have high compatibility and impart excellent low‐temperature, mechanical, heat‐ and light ‐stability properties to the plasticized PVC. The 2‐ethylihexyl ester bis (2‐methoxyethyl) acetal, in particular, appeared to have the best combination of properties for a useful plasticizer. The results indicate that a unique and useful type of plasticizer‐stabilizer can be obtained from derivatives of azelaaldehydic acid.
Determination of stresses in formed plastics parts
Authors: Dixon Robert R. 
Published: December 2004

AbstractTo determine the optimum conditions for vacuum forming quality parts, a precise method of determining internal stress required development. The approach investigated was based on the shrinkage of a heated stressed part. Small stress should be proportioned to strain. By exposing loaded tensile specimens simultaneously with the formed part, the material modulus is determined. Results indicated creep which was minimized by using the correct modulus to calculate internal stress. Stresses in a normally formed part and in a part formed cool were compared at two temperatures. Values were higher in most areas of the cool‐formed part and consistent at the two temperatures. This method probably can be used on other materials and possibly on injection molded parts.
The prediction of ABS extruded sheet surface quality by rheometer behavior
Authors: Weaver E. Paul 
Published: December 2004

AbstractThe behavior and appearance of ABS compounds in rheometers correlate with certain surface characteristics of extruded sheet. Three reometers were studied, each demonstrating the increase of viscosity with time of a destabilized compound over a standard ABS. This behavior shows as low gloss areas on the sheet from the destabilized compound vs uniform gloss for the standard. The Instron Capillary Rheometer proved the useful since extrudates produced can discriminate between compounds at given temperatures on the basis of gloss. The relative gloss of material tested is duplicated on extrusion as measured by a 600 Gardner glossmeter. Dynamic conditions affecting viscosity can also be predicted by the Brabender Plastigraph. Correlations developed, along with the usual physical measurements, permit appaisal of ABS compounds before commercial extrusion.
Influence of annealing on the density and tensile properties of polypropylene
Authors: Schotland R. S. 
Published: December 2004

AbstractThe density and tensile property changes in polypropylene resulting from various post‐crystallization aging procedures are investigated with the aim of (1) establishing standard procedures for the evaluation of these properties and (2) determining which conditioning treatment will provide optimum tensile properties. The morphology and resultant tensile behavior of polypropylene are particularly sensitive to conditioning treatments in the temperature range 145‐160°C. A procedure for compression molding plaques, carrying out isothermal annealing treatment in the 100‐170°C range and gradual cooling is described. The dependence on annealing temperature of the density, elongation, tensile modulus and yield stress is given.
Autoxidation of semicrystalline polyethylene
Authors: Winslow F. H. , Hellman M. Y. , Matreyek W. , Stills S. M. 
Published: December 2004

AbstractThermal oxidation in linear polyethylene is mainly confined to disordered regions in which scission reactions cause crystallization and eventual deterioration of mechanical properties. Gel formation is negligible at 100°C. As degradation proceeds, comparable changes occur in the intrinsic viscosities of melt and solution‐crystallized liner polymers, indicating that chain folds are regularly arranged and are resistant to oxidative scission. Breakdown is much more extensive in branched and crosslinked polymers since crosslinking retards oxidative crystallization and branching increases the volume fraction of substrate ultimately accessible to oxygen.
Molecular weight distribution and environmental stress cracking of linear polyethylene
Authors: Herman James N. , Biesenberger Joseph A. 
Published: December 2004

AbstractMolecular weight distributions of both Phillips and Zieglertype high density polyethylenes were determined following fractionation of the polymer samples using a column elution technique. The Wesslau log normal distribution function was used to describe the distributions of the resins investigated. Resistance to environmental stress rupture of speciments cut from compression molded plaques of these samples was measured by the constant tensile loading procedure. Data are presented showing annealed resins with “broad” molecular weight distributions, characterized particularly by a quantity of low molecular weigt material and a high molecular weight “tail,” to have poorer stress crack resistance than samples having a “narrow” molecular weight distribution. Stress crack resistance of specimens quenched from the melt, however, tends to improve for “broad” distribution resins, while decrasing for those polyethylenes having a “narrow” molecualar weigt distribution. Differences in crystal structure are used to explain the physical bassis for these effects.
Practical applications of polymer solutions
Authors: Billmeyer Fred W. 
Published: December 2004

AbstractTo chemists and engineers working in industry, the most important applications of polymer solutions are the experiments leading to the measurement of molecular weight, molecular‐weight distribution, and other characteristic parameters of random‐coil polymers. This article extends earlier reviews by describing such practical aspects of these measurements as preferred techniques;; commercially‐available equipment; analysis cost, sample size, and time; limitations of the methods; and pitfalls in the interpretation of the data. For molecular‐weight measurement, commonly‐used techniques include end‐group analysis, cryoscropy, ebulliometry, osmometry, “vapor‐pressure osmometry”, light scattering, and ultracentrifugation. Measurement of certain transport properties correlating emprirically with molecular weight, such as the intrinsic viscosity, is useful if the limitations of the techniques are recognized. Currently, the more promising and powerful methods polymer fractopmatopm are cpmsodered to be column elution and gel permeation chromatography.
Polymer structures and properties of new heat resistant films and fibers
Authors: Wallenberger F. T. 
Published: December 2004

AbstractCommercial films, elastomers, and fibers have valuable in‐use properties below 300°C. Astronautic requirements, however, may evaentually call for materials that withstand 500 hrs at 300°C or 100 hrs at 500°C while fully retaining their useful properties. The most significant advances in the synthesis and preparation of heat resistant polymer have been made since 1959 with new synthetic methods such as interfacial polymerization, cyclopolymerization, and intramolecular polymer post‐cyclopolymerization, and intramolecular olymer post‐cyclization reactions. It is the purpose of this paper to discuss the structural relationships among those heat resistant, orgainc polymers that were reported to give strong films and fibers. Those heat resistant polymers, which have not yet been fabricated into films and fibers are not included in this review.
A system of deformation data for rational engineering design with plastics
Authors: Turner S. 
Published: December 2004

AbstractThe paper discusses the deformational behaviour of thermoplastics, particularly in relation to their utilization through rational engineering design procedures. It describes the comprehensive systems of data that are replacing the old single datum quantities published hitherto and comments briefly on the corrdination of materials testing through the activities of B.S.I. Committee PLC/36.
Correlation of physical and polymer chain properties
Authors: Wolstenholme W. E. 
Published: December 2004

AbstractAn idealized polymer model is used to examine the magnitude of the catastrophic tensile breaking energy and stress in terms of primary and secondary bonding forces. Computed strengths for primary and secondary bonding are respectively 8000 and 500 times larger than observed values of a common thermoplastic. From other considerations, the glass transition temperature for both elastomeric and thermoplastic polymers is found to show a linear dependence on the cohesive energy per unit length of polymer chain.In special polymer model, the influence of polymer chains on unidirectional elongation is shown to be a function of chain size. Elongation data reported on a series of modified polycarbonates exhibit a correlation with chain size as described by the model. Published data on the polycarbonate series are used to evaluate the correlation between observed deformation breaking energies and cohesive energies calculated from glass transition temperatures.
Reprocessing polycarbonate/acrylonitrile‐butadiene‐styrene blends: Influence on physical properties
Authors: Eguiazábal J. I. , Nazábal J. 
Published: December 2004

AbstractA commercial polycarbonate (PC)/acrylonitrile‐butadiene‐styrene (ABS) blend was reprocessed by injection molding to study the influence of reprocessing on the physical properties of the product. The modulus of elasticity and the yield stress are unaffected by reprocessing, whereas the break properties and the impact strength decrease. The effects observed are compared with those found in PC and ABS. The type of reactions taking place during reprocessing and the change of blend morphology are also discussed.
Steady solidification of non‐Newtonian fluid flowing in a round tube
Authors: Yang Ling C. , Chen S. J. , Charmchi M. 
Published: December 2004

AbstractThe problem of steady solidification of a power law fluid flowing in a round tube was solved numerically. The fluid considered was a polymer with temperature dependent viscosity. The mathematical solution was obtained by using an implicit finite difference method. Results are presented to show the effects of the Peclet number, Nahme number, and the power law index on the profiles of the frozen layer. Melt temperature profiles at different axial locations are also presented.
Polymeric antiplasticization of polycarbonate with polycaprolactone
Authors: Shuster M. , Narkis M. , Siegmann A. 
Published: December 2004

AbstractPhysical blends of polycarbonate (PC) with polycarprolactone (PCL), containing 0 to 30% PCL were prepared by melt mixing. The compatible blends were studied using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), mechanical testing, rheological and density measurements. Yield strength, elastic modulus, and density of the blends were found to attain maximum values, depending on PCL content, while Tg continuously decreased. PCL presence resulted in the embrittlement of PC as detected by impact and tensile tests. These combined data lead to propose a mechanism of polymeric antiplasticization in the PC/PCL system; a phenomenon uncommon in polymer‐polymer blends. Simultaneously, the PC's β‐transition intensity was depressed, as detected by DMA. Activation energy of PC secondary relaxation process was found to be higher for PC/PCL blends than for PC. Thus, local, intermolecularly non‐cooperative motions, usually associated with β‐relaxation, are restricted in the presence of PCL. The addition of PCL to PC results in increased shear sensitivity and lower high shear rates viscosity, improving processability.
Studies on the properties and structure of electron‐beam crosslinked low‐density polyethylene/poly[ethylene‐co‐(vinyl acetate)] blends
Authors: Dadbin Susan , Frounchi Masoud , Sabet Maziar 
Published: December 2004

AbstractBlends of low‐density polyethylene (LDPE) and poly[ethylene‐co‐(vinyl acetate)] (PEVA), crosslinked by electron‐beam (EB) radiation, formed separate crystalline lattices with a homogeneous amorphous phase. The crystallinity of the EB‐exposed samples slightly decreased, as verified by a slight reduction in the densities and melting heats and temperatures of the samples. The results obtained from both gel content and hot set tests showed that the degree of crosslinking in the amorphous regions was dependent on the dose and blend composition. The molecular weights between the crosslinks, measured from creep data, showed that an increasing PEVA content resulted in tighter network structures, thus supporting the idea that the crosslinking density at a given irradiation dose depends on the amorphous portions of the polymers. Addition of trimethylolpropane trimethacrylate as a radiation sensitizer enhanced the gel content of the neat polyethylene significantly, while the addition of an antioxidant showed the reverse effect. A significant improvement in the tensile strength of the neat PEVA samples was obtained upon EB radiation up to 210 kGy. The irradiated LDPE/PEVA blends showed improved tensile strength and elongation at break when compared to LDPE. Copyright © 2004 Society of Chemical Industry
The Relevance of Powder/Liquid Wettability to the Cohesiveness of Carbon Black Agglomerates
Authors: Ayala Raául E. , Hartley Paul A. , Parfitt Geoffrey D. 
Published: December 2004

AbstractParticle size enlargement operations often involve the use of a liquid to improve powder cohesiveness. Capillary suction and surface tension forces acting through liquid menisci between particles are the primary source of the cohesive bonding. The strength of these forces, and consequently the strength of the wet agglomerate, is dependent upon the total liquid content, its distribution within the agglomerate, and the powder wettability (characterized by the liquid surface tension and powder/liquid contact angle).The tensile strength of powder compacts containing submicron carbon black particles has been measured as a function of saturation level for several liquids. It is found that the compact strength increases with increasing surface tension for liquids that exhibit a zero contact angle. Above the critical surface tension for wetting a more complicated situation exists where both the surface tension and contact angle are important.
Versuch einer Theorie der Trockendestillation von Holz. I
Authors: Klason Peter 
Published: January 2005

Abstract1. Die trockene Destillation des Birkenholzes hat einen primären und einen sekundären Verlauf.Der primäre Verlauf geschieht am reinsten in hohem Vakuum (Kathodenlichtvakuum), wo das Pech wirklich überdestilliert, und zwar im wesentlichen nach der Formel: magnified image Der sekundäre Verlauf geschieht am vollständigsten (bei hohem Druck oder) unter gewöhnlichem Druck bei äußerst langsamer Temperatursteigerung, wobei kein Pech erhalten wird, und zwar im wesentlichen nach der Formel: magnified image Je langsamer die Temperatursteigerung demnach geschieht, um so geringer gestaltet sich die Ausbeute an Pech, und um so höher steigt die Ausbeute an Holzkohle, Wasser, Kohlen‐säure und Pechölen.
Das Gesetz der homöopolaren Atombindung und die Koordinationsverbindungen der Platinmetalle
Authors: Remy H. 
Published: January 2005

AbstractAls Beispiel dafür, wie das früher an den Sauerstoffsäuren abgeleitete Gesetz der homöopolaren Atombindung auf andere Klassen von Koordinationsverbindungen übertragen werden kann, wird dasselbe zur Deutung der Koordinationsverbindungen der Platinmetalle benutzt.
Über die Bindung von Schwefel in der Asche bei der Verbrennung von Kohle unter dem Einfluß saurer oder basischer Aschebestandteile
Authors: Foerster F. , Landgraf A. 
Published: January 2005

AbstractZu Teil I: Durch Einwirkung von SO3 auf CaSiO3 wird, trotz SiO2‐Überschusses, eine teilweise SO3‐Bindung durch das CaO des Silicates erzwungen. Die Gründe für die, unter den obwaltenden Verhältnissen sehr langsame, endgültige Einstellung des von der Temperatur abhängigen Endzustandes der umkehrbaren Reaktion:

werden in vielstündigen Versuchen, bei auf 900° C festgelegter Temperatur, untersucht und schließlich durch Diffusionsvorgänge und grundlegende physikalische Veränderung des CaSiO3 erklärt.
Konstitution und Reaktionsfähigkeit. XII. Mitteilung: Die Nitrierung und Sulfurierung aromatischer Verbindungen
Authors: Lauer Karl 
Published: January 2005

AbstractDie Ergebnisse der Versuche zur Weitersubstitution aromatischer Verbindungen zwingen zu dem Schluß, daß die Substitution aromatischer Verbindungen durch Vorgänge erfolgt, die im wesentlichen durch die Theorie der ionoiden Substitution wiedergegeben werden.
Zur Kenntnis der Kondensation von Chinaldin‐jodäthylat mit Formaldehyd
Authors: Lauer Karl , Horio Masao 
Published: January 2005

AbstractAls Ergebnis unserer Versuche kann festgestellt werden, daß das von W. König aufgestellte Reaktionsschema als zutreffend anzunehmen ist und daß eine der wichtigen Nebenreaktionen im Aufbau von 2‐Äthyl‐chinolin besteht, in deren Verlauf die bei der Pinacyanolbildung frei werdenden zwei Wasserstoffatome aufgenommen werden.
Zur Synthese des α, β ‐ Dichlorbutadiens und seine Polymerisation
Authors: Klebansky A. L. , Wolkenstein A. S. , Orlowa A. 
Published: January 2005

AbstractDie Gewinnung von Dichlor‐1,2‐butadien‐1,3 durch Einwirkung von Monovinylacetylen auf ein Gemisch von CuCl2, CuCl und NH4Cl ist äußerst schwierig, da die Reaktion von der Bildung eines Acetylentetrameren und eines Tetrachlorids begleitet ist.
Über die Umsetzungen der Tetrachloride des Selens und Tellurs mit organischen Stoffen und Über ein einfaches Verfahren zur Darstellung selenorganischer Verbindungen in wäßrigem Medium
Authors: Funk H. , Weiss W. 
Published: January 2005

AbstractSelentetrachlorid wirkt bei vollständigem Feuchtigkeitsausschluß auf organische Substanzen chlorierend ein. Bei Anwesenheit von Spuren Feuchtigkeit werden selenorganische Verbindungen gebildet, wahrscheinlich durch die Entstehung von Selenoxychlorid aus Selentetrachlorid und Wasser. Aus salz‐ bzw. bromwasserstoffsaurer Selendioxyd‐Lösung und einer organischen Komponente kann man leicht und sauber selenorganische Verbindungen in wäßrigem Medium herstellen. Schwefeldioxyd‐ bzw. Tellurdioxyd‐Lösungen geben unter gleichen Bedingungen keine schwefel‐ bzw. tellurorganische Verbindungen. Ferner findet keine Bildung von selenorganischen Verbindungen statt, wenn man SeO2 in anderen als den oben genannten Säuren löst. Tellurtetrachlorid bildet mit organischen Substanzen nur unter Feuchtigkeitsausschluß tellurorganische Verbindungen.
Polarographische Untersuchungen an Xanthocillin
Authors: Schwabe K. , Kaniss N. 
Published: January 2005

AbstractDie polarographische Untersuchung des Antibioticums Xanthocillin ergab zwei charakteristische Stufen bei –1,97V und –2,23V gegen die Normalcalomelelektrode in m/10 Tetraäthylammoniumhydroxydlösung, die sich zu seiner quantitativen Bestimmung eignen. Auch in m/10 Lithiumhydroxydlösung wird eine analytisch verwertbare Stufe bei –2,03V erhalten. Die X und Y‐Komponente des Xanthocillins unterscheiden sich polarographisch nicht. Bei der Reduktion werden insgesamt 2 Elektronen aufgenommen. Der Reduktionsmechanismus wurde diskutiert.
Berechnung von Reaktionen mit statistischem Gleichgewicht
Authors: Boesler Joh. , Budruss Reinhold 
Published: January 2005

AbstractEs wird eine Methode entwickelt, welche gestattet, die Produktzusammensetzung bei Reaktionen mit statistischer Verteilung vorauszubestimmen, andererseits bei Vorliegen von gemessenen Werten die Reaktionsgeschwindigkeiten zu ermitteln.
Eine neue Variante der Methode der inneren Elektrolyse
Authors: Sagortschew B. , Liptschinsky Al. , Schejtanow Chr. 
Published: January 2005

AbstractNach einem Rückblick auf die geschichtliche Entwicklung und einer kritischen Darstellung der bisher üblichen Verfahren wird eine neue einfache Versuchsanordnung erläutert, die infolge Vermeidung von Zementation auch bei hohen Konzentrationen der zu bestimmenden Metallionen sehr genaue Ergebnisse liefert. Es ist, die Möglichkeit gegeben, auch sehr unedle Metalle zu bestimmen.
Über die Autoxydation des 1,3,5‐ Triisopropyl‐benzols, eine neue Synthese des Phloroglucins
Authors: Seidel F. , Schulze M. , Baltz H. 
Published: January 2005

AbstractDie Autoxydation des 1,3,5‐Triisopropyl‐benzols zu den theoretisch möglichen Hydroperoxyden ist grundsätzlich möglich; von entscheidender Bedeutung ist die Reinheit des verwendeten 1,3,5‐Triisopropyl‐benzols. Die Autoxydation wurde photochemisch, ohne UV‐Bestrahlung bei 110° und in wäßriger Emulsion bei 85° durchgeführt; letzteres Verfahren erbrachte die höchsten Ausbeuten. Die Autoxydation verläuft über das Mono‐ und Di‐ zum Trihydroperoxyd des 1,3,5‐Triisopropyl‐benzols. Diese drei Hydroperoxyde lassen sich selektiv darstellen. Durch säurekatalytische Spaltung werden sie in Aceton und entsprechend in 3,5‐Diisopropylphenol, 5‐Isopropylresorzin und Phloroglucin zerlegt. Die Ausbeuten an Phenolen vermindern sich in der Reihenfolge 3,5‐Diisopropylphenol 5‐Isopropylresorzin, Phloroglucin. Die Reduktion der Hydroperoxyde des 1,3,5‐Triisopropylbenzols ergibt die entsprechenden tertiären Alkohole, die sich in Derivate der Thioglykolsäure überführen lassen.