Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Macromolecules 23 (1990), S. 12-14 
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The glass transition behavior of ternary blends of polypropylene (PP), polystyrene (PS) and styrene-ethylene-propylene-styrene block copolymer (SEPS) was investigated. The blends were prepared by an internal mixer, and their dynamic mechanical properties and morphology were measured. The blends showed phase inversion at around 75wt% PS composition. The glass transition temperature (Tg) of the PP phase shifted to lower temperature as the PS contents were increased in PP/PS binary blends, probably due to the mismatch of thermal expansion coefficients between two components. As the SEPS copolymer contents were increased, the Tg's of the PP phase in the blends increased. In particular, the large increase in Tg of the PP phase was observed in the PP/PS (25/75) blends where the phase inversion takes place.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Poly(amide-imide)s(PAIs) with different microstructures were prepared based on trimellitimide and 4,4'-diphenylether with varying the reaction conditions. The microstructures of PAIs were examined by 500MHz 1H-NMR spectroscopy. The head-to tail (HT-) PAI showed a sharp peak in WAXD curve, a large shift at around 1670 cm−1 for −C=O stretching in FT-IR spectra, and poor solubility in organic solvents, high density, Tg, tensile strength and modulus compared to head-to-head (HH-) PAI and copolymers of HT and HH. These results might be due to the higher packing tendency of the HT PAI than HH PAI or copolymers.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary A series of t-butyloxycarbonyloxy (t-hoc-oxy) attached polyamide (t-bocPA) as a polybenzoxazole (PBO) precursor was synthesized from poly(o-hydroxyamide) (PAOH) and its thermal conversion to PBO was investigated by using FT-IR, TGA and DSC. Most of the protecting group of t-bocPA was decomposed at 250 °C and the polymer converted to PBO at 350 °C. The thermal reaction for PBO formation was accelerated by the strong acid such as p-toluenesulfonic acid. It was revealed that photo-acid generator (PAG) can act not only as an acid generator on UV exposure, but also as a catalyst to lower the temperature of PBO formation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    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: Ein neues, wirtschftliches Verfahren zur Herstellung hochmolekularer Poly(amidimid)e (PAIs) basiert auf der direkten Polykondensation von Trimellitsäureanhydrid(TMA) oder Diimid-Disäuren (DIDAs) mit aromatischen Diaminen in Gegenwart von äquimolaren Mengen an Thionylchlorid in N-Methylpyrrolidon bei relativ niedrigen Temperaturen. Die Polyamidierung von Diimid-Disäuren und Diaminen zu Kopf-Kopf-Polymeren (H-PAIs) ist temperaturempfindlich und verläuft rasch; die Reaktionsdauer von 1 h war für die vollständige Umsetzung ausreichend. Der höchste Wert für die inhärente Viskosität ηinh wurde mit 72 mL g-1 bei Polymerisation bei Raumtemperatur erzielt. Durch die Polykondensation von TMA mit Diaminen und anschließende Imidisierung nach verschiedenen Methoden, wie die azeotrope Dehydrierung bzw. die Festphasenimidisierung von Polyamsäuren oder der Einsatz von Triphenylphosphit als Cokondensationsagens, wurden ebenfalls einige statistisch aufgebaute Polymere (R-PAJs) hergestellt. Von den Imidisierungsmethoden ergab die Festphasenimidisierung von Polyamsäuren mit inhärenten Viskositäten ηinh von 58-85 mL g-1 zufriedenstellende Ergebnisse. Imidisierungsgrade und Molekulargewichte wurden im wesentlichen von der Lösungsmittelmenge sowie der Imidisierungstemperatur und -zeit bestimmt. Sowohl H-PAI als auch R-PAI zeigten gute mechanische Eigenschaften, je nach Ausgangsmonomeren lagen die Zugfestigkeiten im Bereich 118-131 MPa und die Glasübergangstemperaturen im Bereich von 263-299°C. Die Schmelzviskositäten der PAIs bewegten sich zwischen 7,4·103 und 4,5·103 Pa s für H-PAI bzw. R-PAI und sind mit dem Wert fur konventionelles PAI, Torlon® 4000T, von 5,6·103 Pa s vergleichbar.
    Notes: A study for the development of a new, economical manufacturing process for high-molecular-weight poly(amide-imide) (PAI) was performed via direct polycondensation of trimellitic acid anhydride (TMA) or diimide diacids (DIDAs) with aromatic diamines using an equimolar amount of thionyl chloride in NMP at relatively low temperatures. The polyamidation of DIDAs and diamines for head-to-head polymers (H-PAIs) was sensitive to the reaction temperature and proceeded very quickly, 1 h was sufficient to complete the reaction. The highest value of inherent viscosity, ηinh, of 72 mL g-1 was obtained by polymerization at room temperature. Also several randomly sequenced polymers (R-PAIs) were prepared by polycondensation from TMA and diamines, followed by imidization with various methods, such as using TPP as a co-condensing agent, azeotropic dehydration of polyamic acid (PAA) and solid-state imidization from PAA. Solid state imidization from polyamic acids at 235°C gave satisfactory results with an inherent viscosity 58-85 mL g-1. Solvent content, imidization temperature and time were major controlling factors for the degree of imidization as well as for the molecular weight. Both H-PAI and R-PAI showed good mechanical properties with tensile strength of 118-131 MPa and Tg ranged between 263-299°C depending on the nature of monomers. The melt viscosity of the PAIs ranged between 7.4 · 103 and 4.5 · 103 Pa s for H-PAI and R-PAI respectively. These values are comparable to that of conventional PAI, Torlon® 4000T of 5.6 · 103 Pa s.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 1575-1581 
    ISSN: 0887-624X
    Keywords: polyarylates ; pendant silyl group ; two-phase polycondensation ; tough films ; good thermal stabilities ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyarylates containing pendant silyl group were prepared by the phase-transfer catalyzed, two-phase polycondensations of 2,2-bis (4-hydroxyphenyl) propane with corresponding dicarbonyl chlorides such as 2-trimethylsilylterephthaloyl chloride, 5-trimethylsilylisophthaloyl chloride, 5-dimethylphenylsilylisophthaloyl chloride, and 5-triphenylsilylisophthaloyl chloride. The resulting amorphous polyarylates with glass transition temperatures of 163-214°C had inherent viscosities in the range of 0.41-0.95 dL/g. These polyarylates were readily soluble in common chlorinated hydrocarbons and it was possible to obtain transparent, flexible, and tough films from the polymer solutions. The prepared polyarylates showed fairly good thermal stabilities as well as tensile strengths, i.e., the tensile strengths of the cast films from chloroform solution were 6.0-6.7 kg/mm2. And TGA data revealed 10% weight losses and residual weights at 800°C were 437-495°C and 27-40% under nitrogen atmosphere, respectively. © 1992 John Wiley & Sons, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 27 (1989), S. 443-449 
    ISSN: 0887-6258
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...