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  • 1
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 297-300 (Nov. 2005), p. 703-709 
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Interfacial stress singularities induced in a laminate model consisting of the viscoelastic thin film and the elastic substrate have been investigated using the time-domain boundary element method. First, the interfacial singular stresses between the viscoelastic thin film and the elastic substrate subjected to a uniform moisture ingression have been investigated near the free surface, but without any edge crack. The thin film is assumed to be a linear viscoelastic material and moistureeffects are assumed to be analogous to thermal effects. Then, the overall stress intensity factor for the case of a small interfacial edge crack of length a has been computed. The numerical procedure does not permit calculation of the limiting case for which the edge crack length vanishes
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 321-323 (Oct. 2006), p. 1377-1380 
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The residual stresses in a polymeric thin film deposited on Si wafer induced during coolingfrom a cure temperature down to room temperature are investigated. The laser scanning method andthe boundary element method (BEM) are employed to investigate the residual stresses. A 3 μm thickpolyimide film is deposited on a relatively thick Si wafer. The normal stress across thickness of thethin film is estimated from wafer curvature measurements to be 20MPa . The boundary elementmethod is employed to investigate the whole stresses in the film. The numerical result for the normalstress across thickness of the film, σ xx , shows good agreement with the experimental result obtainedby using the laser scanning method. The singular stress is observed near the interface corner. Suchresidual stresses are large enough to initiate interface delamination to relieve the residual stresses
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 25 (1987), S. 2021-2024 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 28 (1990), S. 3179-3184 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 2417-2426 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of polyketones containing thiophene links was synthesized by the Friedel-Crafts polymerization of these dithienylalkanes with aromatic diacid chlorides or dicarbonyl chlorides comprising thiophene links with diphenyl compounds. The resulting polymers had inherent viscosities in the range of 0.11-0.27 dL/g and showed poor solubilities to common organic solvents except strong acids. These thiophene-based polyketones exhibited fairly good thermal stabilities. The TGA data revealed 5% weight losses at 375-450°C and residual weights at 500°C were 43-79% under nitorgen. It was found that the thermal stabilities of these polymers were superior to those of polymides or polysulfonamides containing thiophene links and almost comparable to common aromatic polyketones
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1507-1517 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to study the synthesis and properties of polysulfonamides containing thiophene links, 2,2-bis(5-chlorosulfonyl-2-thienyl)propane [BCTP], 2,2-bis(5-chlorosulfonyl-2-thienyl)butane [BCTB], 1,1-bis(5-chlorosulfonyl-2-thienyl)cyclohexane [BCTC], and 2,4-dichlorosulfonyl thiophene [DCST] were prepared and interfacial polycondensations with various aliphatic diamines were carried out. The resulting polymers had inherent viscosities in the range of 0.13-0.41 dL/g and showed high extent of moisture absorptions. Most of the polysulfonamides were soluble in electron-donating solvents such as pyridine, DMF, DMSO, NMP, etc. These polysulfonamides exhibited relatively good thermal stabilities. The TGA data revealed 5% weight losses at 275-405°C and residual weights at 500°C were 13-40% under nitrogen. It was also found that dithienyldisulfonyl chlorides produced more thermally stable polymers than DCST, which were comparable to common polysulfonamides from aromatic disulfonyl chlorides.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 1583-1588 
    ISSN: 0887-624X
    Keywords: aromatic polyamides ; pendant silyl groups ; direct polycondensation ; improved solubilities ; good thermal stability ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to improve the solubility of aromatic polyamides without significant loss of thermal stability, synthesis of aromatic polyamides containing pendant silyl groups was carried out by direct polycondensation of silylated aromatic diacids such as 2-trimethylsilylterephthalic acid (TSTA), 2,5-bis (trimethylsilyl) terephthalic acid (BTSTA), 5-trimethylsilylisophthalic acid (TSIA), 5-dimethylphenylsilylisophthalic acid (DMSIA), and 5-triphenylsilylisophthalic acid (TPSIA) with various aromatic diamines. The resulting polyamides had inherent viscosities in the range of 0.18-1.10 dL/g and showed improved solubilities toward aprotic polar solvents such as NMP, DMF, DMSO, etc. The prepared aromatic polyamides exhibited fairly good thermal stabilities, which were almost comparable to those of corresponding nonsubstituted aromatic polyamides. That is, thermogravimetric analysis (TGA) data revealed 10% weight losses at 358-500°C and residual weights at 700°C were 46-67% under nitrogen atmosphere. © 1992 John Wiley & Sons, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 175-179 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 222 (1994), S. 103-109 
    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: Neue aromatische Polyamidimide (PAI) wurden durch Reaktion von Torlon® 4203L (ein handelsübliches PAI) mit verschiedenen Halogenalkanen (Methyliodid, Ethyliodid, n-Butylbromid) hergestellt. Die Glastemperaturen dieser amorphen PAI liegen zwischen 238 und 276°C, die Grenzviskositäten betragen 51 bis 53 mL/g. Die PAI sind leicht löslich in polaren, aprotischen Lösungsmitteln wie z.B. N-Methylpyrrolidon, Dimethylformamid, Dimethylacetamid u.a. Der Einbau der Alkylsubstituenten in die Amidgruppen der PAI verbesserte die Verarbeitbarkeit aus der Schmelze, verringerte allerdings die thermischen Eigenschaften im Vergleich zu einem konventionellen PAI. Die bei 330°C und einer Frequenz von 0,1 rad/s gemessenen Schmelzviskositäten der hergestellten PAI betragen 103-105 Pa.s. Andererseits sind die Schmelzviskositäten der modifizierten PAI geringer als die von Torlon® 4203L, das mit dem konventionellen Polyetherimid Ultem-1000 vergleichbar ist.
    Notes: New aromatic polyamide-imides (PAI) containing various alkyl substituents were prepared by the substitution reaction of Torlon® 4203L (commercialized PAI resin) with the corresponding alkyl halides such as methyl iodide, ethyl iodide, and n-butyl bromide. The resulting amorphous PAIs with glass transition temperatures ranging from 238 to 276°C had inherent viscosities in the range of 51 to 53 mL/g. These polymers were readily soluble in aprotic polar solvents such as N-methylpyrrolidone, dimethylformamide, dimethyl acetamide, etc. Furthermore, the incorporation of various alkyl substituents into amide groups of the PAI resin increased the melt processability, but slightly decreased the thermal properties compared with conventional PAI resin. The melt viscosities of resulting PAIs determined at 330°C under the frequency of 10-1 rad/sec were in the range of 103-105 Pa.s. On the other hand, the modified PAIs showed significantly lower melt viscosities than Torlon® 4203L, which was almost comparable to the conventional polyetherimide, Ultem-1000.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 233 (1995), S. 89-101 
    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: Neuartige Poly(amidimid)e (PAI) mit aliphatischen Diaminen als Comonomersegmente wurden durch Polykondensation von Trimellitsäureanhydridchlorid mit gemischten Aminen hergestellt. Die Ergebnisse von Copolymerisationsversuchen mit verschiedenen alicyclischen Diaminen ließen Isophorondiamin (IPDA) als geeigneteres Comonomeres für Poly(amidimid)e erscheinen. Die erhaltenen Copoly(amidimid)e zeigten, daß die IPDA-Segmente im Vergleich zu aromatischen Diaminen, die in einer vorangehenden Arbeit beschrieben wurden, starrer sind als m-BAPS und 4,4′-Diaminodiphenylether, jedoch weniger starr als m-PDA. Die hergestellten PAIs besitzen gute mechanische Eigenschaften mit Zugfestigkeiten von 105 ∼ 118 mPa. Die Glastemperaturen liegen je nach Molekulargewicht und dem eingesetzten Comonomeren zwischen 232°C und 301°C. Die Löslichkeit konnte durch den aliphatischen Charakter des IPDA erhöht werden. Auch die rheologischen Eigenschaften verbesserten sich im Vergleich zu konventionellem PAI. Die Schmelzviskositäten der Copolymeren lagen zwischen 1.6 · 103 und 2.1 · 103 Pa · s. Die beschriebenen PAIs könnten sich somit zur Herstellung von aus der Schmelze verarbeitbaren Hochleistungspolymeren eignen.
    Notes: New poly(amideimide)s (PAI) containing aliphatic diamines as comonomers were synthesized by polycondensation of trimellitic anhydride chloride with mixed diamines. Preliminary results of copolymerization with various alicyclic diamines suggested that isophoronediamine (IPDA) is more preferable as a comonomer for PAI. The copolyamide imides with IPDA showed that IPDA is more rigid than mbisaminophenoxydiphenylsulfoneSystematic name: 4,4′-Sulfonylbis(1,3-phenylenoxy)dianiline. (m-BAPS) and 4,4′-diaminodiphenyl ether (ODA), but less than m-phenylenediamine (m-PDA). And they showed good mechanical properties with 105 ∼ 118 MPa of tensile strength and Tg's were ranged 232 ∼ 301 °C depending on molecular weight and comonomers. The solubility was improved due to the aliphatic character of IPDA in the copolymers. Rheological properties were also improved compared with conventional PAI. The melt viscosity of the copolymers ranged 1.6 · 103 ∼ 2.1 · 103 Pa · s, thus, the reported PAIs may be considered to be new candidates for melt processable high-performance polymer materials.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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