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  • 1975-1979  (51)
  • 1965-1969  (29)
  • Organic Chemistry  (43)
  • Polymer and Materials Science  (37)
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 10 (1979), S. 449-455 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: The Prevention of Inertial Force Measurement Inaccuracies Encountered in Pendulum-type DynamometersTest machines, which are equipped with a force measuring device utilizing the inclining pendulum, are subject to dynamic measurement inaccuracies due to the inertia of the pendulum.The initial discussion demonstrates that the dynamic inaccuracy of measurement encountered with test machines using an inclining pendulum - force measurement device can only be calculated for the complete test machine/test piece configuration. With reference to the results of experiments, it will be proved that, as with the experiments carried out by Kravcenko, the indicated dynamic force and the dynamic force in the testpiece are antiphase and unequal.Additionally it will be shown that, through the experiment results, the equation from Schultze/Baumann for the permissible rate of test is confirmed only in the interpretation from Kravcenko.Further equations concerning the limitations of the rate of test are shown and their relevant fields of applications are discussed. Finally, factors are presented which stipulate a reduction of the permissible rate of test or permit an increase in this rate, dependent upon the force-elongation characteristic of the test piece and the measured variable under consideration.
    Notes: An Prüfmaschinen, welche Kraftmeßeinrichtungen mit Neigungspendeln besitzen, treten durch die Trägheit des Pendels dynamische Meßfehler auf.Es wird zunächst klargestellt, daß die dynamischen Meßfehler bei Prüfmaschinen mit Neigungspendel-Kraftmeßeinrichtungen nur für das Gesamtsystem Prüfmaschine/Probe berechnet werden können.Anhand von Versuchsergebnissen wird nachgewiesen, daß - entsprechend Untersuchungen von Kravčko - die angezeigte dynamische Kraft und die dynamische Probenkraft gegenphasig und ungleich sind. Außerdem wird gezeigt, daß durch die Versuchsergebnisse die Gleichg. von Schultze/Baumann für die zulässige Prüfgeschwindigkeit nur in der Deutung von Kravčko bestätigt wird.Weitere Gleichungen für Die Begrenzung der Prüfgeschwindigkeit wer den angegeben und ihr Einsatzbereich besprochen. Schließlich werden Faktoren angegeben, die je nach dem Kraft-Verlängerungs-Verhalten der Probe und je nach der gesuchten Meßgröße eine Verringerung der zulässigen Prüfgeschwindigkeit bedingen oder eine Vergrößerung der selben zulassen.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 719-725 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A variety of blends of ABA poly(styrene-b-isoprene) copolymers with poly(2,6-dimethylphenylene oxide) were prepared. Their compatibility was examined by measuring both the apparent modulus of rigidity and the loss tangent. Several blends showed a unique glass transition temperature between those of the individual components, which indicated compatibility. It was found that only those copolymers which phase separate are compatible with poly(2,6-dimethylphenylene oxide).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 12 (1968), S. 1803-1805 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 13 (1969), S. 721-744 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Although sulfonium salts are well known, polymeric sulfonium salts seldom have been mentioned in the chemical literature. This paper describes exploratory work in the preparation of various sulfonium monomers and polymers from ar-vinylbenzyl chlorides (ortho and para isomers). These chlorides - particularly the para isomer - reacted readily with 2,2′-thiodiethanol and water to yield the corresponding ar-vinylbenzyl sulfonium chloride monomers in aqueous solution. The odorless, reactive monomer mixture polymerized readily with persulfate or hydroperoxide catalysts; however, polymerization could be inhibited with cupric salts. Copolymerization with trimethyl(ar-vinylbenzyl)ammonium chloride was random. In copolymerization with acrylamide or acrylonitrile, the sulfonium monomer was more reactive. Analogous sulfonium monomers were made by reaction of ar-vinylbenzyl chlorides with various sulfides. In general, all the sulfonium monomers yielded homopolymers which were fairly stable in aqueous solution in the absence of strongly nucleophilic agents which would attack the sulfonium groups. However, when dried at room temperature the polymers would crosslink; and when heated, the polymers became hydrophobic also. Scrambling of the sulfonium group substituents during drying, and nucleophilic displacement reactions by chloride ion during heating were likely explanations. The high cationic charge on the polymers made them substantive to cellulose fibers. This property, when coupled with high nucleophilic reactivity of the sulfonium groups with the carboxylate sites of the pulp or other anionic counterious during drying and heating, made the polymers very effective as beater additives for imparting wet strength to paper.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 10 (1976), S. 929-938 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The addition of up to 10 g gentamicin sulfate antibiotic powder to 60 g units of Simplex-P acrylic bone cement caused gradual, proportional decreases in the bulk mechanical properties of compressive and diametral tensile stengths. Water leaching of the antibiotic from the cement did not significantly decrease these strengths.Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) showed the antibiotic to reside in the acrylic matrix as discrete particles not usually associated with internal porosity. The surface-sensitive flexural strength of a proprietary bone cement was lowered immediately by small quantities of antibiotic powder, and continued to decrease as doses of up to 10 g/unit were admixed. Water leaching caused channeling as the antibiotic was removed from the surface, but it did not create further changes in flexural strength.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 9 (1975), S. 611-621 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The influence of both imposed anodic potential in Ringer's solution and surface finish on the fatigue lives of annealed 316 type stainless steel and annealed pure titanium were measured and statistically compared to fatigue data run in air. The applied potentials in simulated extracellular fluid approximated conditions existing within the body while also producing the types of surface defects actually found on removed long time implants within the time interval of the accelerated R. R. Moore fatigue tests. Differentiating tests were run at single levels of applied cyclic stress well above the endurance limits.In Ringer's solution, the fatigue life of the 316 stainless steel decreased with increasing applied potential, and at +500 mV was significantly shorter than when run in air. At each condition, the 316 stainless steel was independent of initial surface finish. In contrast, the fatigue life of titanium improved rapidly with increasingly fine surface finishes. Furthermore, compared to air, the application of +500 mV in Ringer's solution improved the life of the rough surface finished material and markedly increased the number of cycles to failure for the electropolished specimens.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 11 (1977), S. 859-869 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Monomer losses for two self-curing acrylic cements were similar via laboratory serial weighing experiments. Both the P/L ratio and mixing duration substantially influenced subsequent monomer losses, but ambient temperature variation during mixing had little effect. Greater losses were encountered during the mixing and setting intervals than during the molding interval. Patient potential exposure to monomer occurs during the molding and setting intervals; therefore, handling procedures reducing losses in these intervals are important to the surgeon.The least monomer loss during both molding and setting occurred at the manufacturers' recommended P/L ratio, which strongly indicated the need to mix all contents supplied. Mixing loss increased with amount of spatulation. However, once the mass was well mixed (about 300 steady spatulations), no further decreases in the molding and setting interval losses were promoted by overmixing. Because of the lower monomer loss rate during the molding interval, postponed cement insertion may not be warranted in light of losing mechanical locking efficiency. The actual ramifications of a threefold reduction in potential patient exposure (3.5 down to 1.2 wt % of total monomer) via modified handling techniques have not yet been clinically evaluated.
    Additional Material: 7 Ill.
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  • 9
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Phthalocyanine complexes of aluminium (1) and silicium, germanium (2) can be incorporated covalently in polyesters by reactions at the central metal ion. Investigations during the polycondensation reaction and with completely condensated polyesters show that the covalent incorporation of 1, 2 takes place between the carboxyl groups and the metal ions of 1, 2. Already 10-4 molar quantities of the complexes colour the polyesters intensively. The thermal properties and hydrolytic stabilities are not influenced. The covalent incorporation is also possible during polymerisation of ε-caprolactone and during polyaddition reactions.
    Notes: Phthalocyaninkomplexe des Aluminiums (1) und des Siliciums bzw. Germaniums (2) können über Reaktionen am zentralen Metallion kovalent in Polyester eingebaut werden. Untersuchungen bei der Polykondensation und an fertigen Polyestern aus Adipinsäure/Ethylenglykol(PEA) bzw. Terephthalsäuredimethylester/Ethylenglykol(PET) ergeben, daß der kovalente Einbau von 1, 2 über die Carboxylgruppen an die Metallionen von 1, 2 erfolgt. Bereits durch 10-4 molare Mengen an Farbstoff werden die Polyester intensiv eingefärbt. Das thermische Verhalten und die hydrolytische Beständigkeit werden nicht beeinflußt. Auf den kovalenten Einbau bei der Polyreaktion von ε-Caprolacton und bei Polyadditionen wird hingewiesen.
    Additional Material: 1 Ill.
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  • 10
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Sechs verschiedene segmentierte Copolyetherester basierend auf Polybutylenterephthalat als hartem und Oligotetramethylenoxidglykol als weichem Segment wurden untersucht. Der Gewichtsbruch der Hartsegmente lag zwischen 0,26 und 0,72, und die Weichsegmente hatten Molgewichte von entweder 1000 oder 2000. Das Schmelz-, Rekristallisations- und Temperverhalten sowie Relaxationsphanomene wurden untersucht; letzteres mit Hilfe eines Torsionspendels.Die DSC-Daten zeigen, daI3 nur ein kleiner Teil aller Hartsegmente kristallisiert. Sequenzen, die kiirzer oder langer als die mittlere Sequenzlange sind, kristallisieren nicht, sondern bilden zusammen mit den Weichsegmenten eine homogene amorphe Matrix, in die die kristallinen Domanen eingebettet sind. Diese Domanen werden infolge kalten Flusses unter Spannung vollstandig zerstort, bilden sich jedoch bei Temperung der verstreckten Proben wieder aus. Man beobachtet ein exponentielles Anwachsen der Langperiode mit zunehmender Tempertemperatur, wobei der Schmelzpunkt konstant bleibt. Die Sequenzlangenverteilung scheint keinen EinfluB auf das Temperverhalten zu haben.
    Notes: Six different segmented copolyether-esters based on polybutyleneterephthalate as the hard and oligotetramethylene oxide glycols as the soft segments were studied. The weight fraction of the hard segments varied between 0.26 and 0.72 and the soft segment had an average molecular weight of either 1000 or 2000. The melting, recrystallization, and annealing behavior was studied as well as the relaxation behavior via measurement by a torsion pendulum. The DSC-data indicate that only a small fraction of all hard segment sequences crystallize. Sequences shorter or longer than the average sequence length do not crystallize but together with the soft segments form a homogeneous amorphous matrix in which the crystalline domains are embedded. These domains are completely destroyed by cold flow under stress but are formed again on annealing the stretched sample. An exponential increase of the long spacing is observed with increasing annealing temperature without change in melting temperature. The sequence distribution does not seem to influence the annealing behavior.
    Additional Material: 8 Ill.
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