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  • 1
    Electronic Resource
    Electronic Resource
    Spacer-modified polymeric catalysts containing phosphonium salts for a regioselective addition reaction of epoxy compounds with active esters (1990)
    s.l. : American Chemical Society
    Macromolecules 23 (1990), S. 3406-3411 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma00216a003
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  • 2
    Electronic Resource
    Electronic Resource
    Soluble Polymer-Supported Catalysts Containing Pendant Quaternary Onium Salt Residues for Regioselective Addition Reaction of Epoxy Compound with Active Ester (1994)
    s.l. : American Chemical Society
    Macromolecules 27 (1994), S. 7240-7247 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma00103a003
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  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and properties of a new o-cresol novolak epoxy resin containing oxyethylene units (1990)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 181 (1990), S. 199-205 
    Details
    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 o-Kresol-Novolak-Epoxidharz mit Oxyethylen-Einheiten wurde hergestellt und charakterisiert. Die thermischen und mechanischen Eigenschaften des mit Methylhexahydrophthalsäureanhydrid gehärteten Harzes wurden untersucht und mit einem konventionellen o-Kresol-Novolak-Epoxidharz (EOCN 1020) verglichen; das neue Epoxidharz zeigte dabei nach dem Härten eine höhere Flexibilität als das herkömmliche.
    Notes: A new o-cresol novolak epoxy resin containing oxyethylene units was synthesized and characterized. The mechanical, thermal, and dynamic mechanical properties of resins cured with methyl hexahydrophthalic anhydride were examined and compared to those of a conventional o-cresol novolak epoxy resin (EOCN 1020). This new epoxy resin gives a cured resin with higher flexibility, compared to the conventional one.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1990.051810117
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesis and properties of new tetrafunctional epoxy resins containing oxyethylene units (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 41 (1990), S. 2301-2310 
    Details
    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: Tetraglycidyl ethers of 2,2′,2″,2‴[sulfonyl bis(4,1-phenylenenitrilo)] tetrakisethanol and 2,2′,2″,2‴[methylene bis(4,1-phenylenenitrilo)]tetrakisethanol were synthesized and characterized. Curing reactivities of these new epoxy resins are investigated by differential scanning analysis. The mechanical, thermal, and dynamic mechanical properties of these resins cured with p,p'-diaminodiphenylsulfone were examined and compared to those fo the conventional tetrafunctional epoxy resin (MY-720). These new epoxy resins have the advantages of being easier to handle, having higher curing reactivities, and giving cured resins with higher toughness, compared with MY-720 resin.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1990.070410932
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  • 5
    Electronic Resource
    Electronic Resource
    Modification of epoxy resins with poly(aryl ether ketone)s (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 43 (1991), S. 1685-1692 
    Details
    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: Poly(aryl ether ketone)s were used as modifiers for bisphenol-A diglycidyl ether epoxy resin (AER 331) cured with methyl hexahydrophthalic anhydride. Poly(phthaloyl diphenyl ether) (PPDE), soluble in the uncured epoxy resin without using solvents, was prepared by the Friedel-Crafts reaction of phthaloyl chloride and diphenyl ether. The mechanical, thermal, and dynamic viscoelastic properties of the modified resins with PPDE were examined and compared to the parent resin (AER 331). The fracture toughness, KIC, for the modified resins increased at no expense to their mechanical and thermal properties on 10 wt % addition of PPDE with molecular weights of more than 17,000. The toughening mechanism is discussed based on the morphological and dynamic viscoelastic behaviors of the modified epoxy resin system.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070430911
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  • 6
    Electronic Resource
    Electronic Resource
    Toughening of epoxy resins by modification with aromatic polyesters (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 43 (1991), S. 463-474 
    Details
    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: Aromatic polyesters, prepared by the reaction of phthalic or isophthalic acids and α,ω-alkanediols, were used to reduce the brittleness of bisphenol-A diglycidyl ether epoxy resin cured with methyl hexahydrophthalic anhydride. These polyesters were effective as modifiers for toughening of the epoxy resin system. The most suitable composition for modification of the epoxy resins was inclusion of 20 wt % of poly(ethylene phthalate) (MW 7200), which resulted in a 150% increase in the fracture toughness (KIC) of the cured resin at no expense of its mechanical properties. The effectiveness of poly(alkylene phthalate)s as modifiers decreased with increasing the chain length of alkylene units. The toughening mechanism was discussed based on the morphological and dynamic mechanical behaviors of the modified epoxy resin system.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070430307
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  • 7
    Electronic Resource
    Electronic Resource
    Synthesis and phase-transfer catalytic activity of crown ethers bound to microporous polystyrene resins by oxyethylene spacers (1992)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 1089-1097 
    Details
    ISSN: 0887-624X
    Keywords: polymer-supported monoazacrown ethers ; phase-transfer catalysis ; spacer ; cooperative coordination ; complexation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Crown ethers bound to microporous polystyrene resins by oxyethylene spacers were prepared by the reaction of monoazacrown ethers with 2-tosyloxyethoxymethylated or 2-(2-tosyloxyethoxy)ethoxymethylated polystyrene resins crosslinked with 2 mol % of divinylbenzene. The activity of the immobilized lariat crowns for halogen exchange reactions under triphase conditions has been studied as a function of catalyst structure, loading, substrate structure, reagent structure, and solvent. The lariat catalysts with extra oxygen donors in the spacer chain exhibited higher activity than the corresponding immobilized catalysts without the donors in the spacer. The increased activity of the catalyst containing 15-crown-5 unit and two extra donors for the reaction of 1-bromooctane with KI was concluded to result from the enhanced complexation with the K+ ion, induced by the cooperative coordination of the crown unit donors and the donors in the spacer chain. The recovered catalysts could be re-used without decrease in activity.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1992.080300615
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  • 8
    Electronic Resource
    Electronic Resource
    Insoluble polystyrene-bound quaternary onium salt catalysts for the synthesis of cyclic carbonates by the reaction of oxiranes with carbon dioxide (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 939-947 
    Details
    ISSN: 0887-624X
    Keywords: polymer-supported onium salt catalyst ; catalytic effect ; synthesis of cyclic carbonate ; oxirane ; carbon dioxide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The addition reaction of oxiranes (26a - e) with carbon dioxide (CO2) was performed using insoluble polystyrene beads containing pendant quaternary ammonium or phosphonium salts as catalysts under atmospheric pressure. The reaction of 26a - e with CO2 proceeded smoothly catalyzed by 1-2 mol % of the polymer-supported quaternary onium salts to give the corresponding cyclic carbonates (27a - e) in high yields at 80-90°C. In this reaction system, the catalytic activity of the polymer-supported quaternary onium salts was strongly affected by the following factors: degree of ring substitution (DRS) of the onium salt residues to the polymer, degree of crosslinking (DC) of the polystyrene beads, chain length of the alkylene spacer between the polymer back-bone and the onium salt, hydrophobicity of the alkyl group on the onium salts, and kind of onium salts. That is, the polymer-supported quaternary phosphonium salts with low DRS and DC and with long alkylene spacer chain were found to have higher catalytic activity than low molecualr weight quaternary onium salts. The above polymer-supported catalysts can easily be separated at the end of a reaction by filtration and can be reused for at least seven runs. It was also found that the rate of reaction was proportional to the products of catalyst concentration and oxirane concentration. © 1993 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080310412
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  • 9
    Electronic Resource
    Electronic Resource
    Phase-transfer catalytic activity of soluble polystyrenes containing crown ether moieties and hydroxyl groups adjacent to the macrorings (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1543-1550 
    Details
    ISSN: 0887-624X
    Keywords: polymer-supported hydroxyl-containing monoazacrown ethers ; phase-transfer catalysis ; elimination ; alkoxide formation ; self-solvated alkoxides ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Soluble polystyrenes with crown ether structures and hydroxyl groups adjacent to the macrorings were prepared by the reaction of epoxide-containing polystyrenes with monoaza-15-crown-5 or monoaza-18-crown-6. Rate of formation of the polymer-bound alkali cation-crown alkoxide ion pair from the soluble polystyrenes and aqueous NaOH or KOH depended on the loading of crown ether and hydroxyl units and on the size of the macroring. The elimination of HCl from less reactive 2-chloroethylbenzene with aqueous NaOH or KOH in the presence of the soluble polystyrene catalysts under two-phase conditions was limited mainly by the intrinsic reaction rate. The elimination of HBr from more reactive 2-bromoethylbenzene in the presence of the less (11%) ring-substituted polymer catalyst with 18-crown unit was limited by the alkoxide formation rate. © 1994 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080320815
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  • 10
    Electronic Resource
    Electronic Resource
    Toughening of epoxy resins by N-phenylmaleimide-N-cyclohexylmaleimide-styrene terpolymers (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 48 (1993), S. 1859-1868 
    Details
    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: N-Phenylmaleimide (PMI)-N-cyclohexylmaleimide (CMI)-styrene (St) terpolymers were used to improve the touchness of bisphenol-A diglycidyl ether epoxy resin cured with p,p′-diaminodiphenyl sulfone (DDS). The terpolymers were effective as modifiers for toughening of the epoxy resin system. The most suitable compositions for the modification of the epoxy resin were inclusion of 10 wt% of the terpolymer (45 mol % PMI, 5 mol % CMI, and 50 mol % St units) with Mw higher than 247,000, which led to ca. a 140% increase in the fracture toughness (KIC) of the cured resin with a medium expense of mechanical properties. The glass transition temperatures of the modified resins were equal to or higher than that of the parent epoxy resin. The morphologies of the modified resins were dependent on the terpolymer molecular weight and concentration. On addition of 5 wt % of the terpolymer (Mw 400,000), the modified resins had two-phase morphologies and the terpolymer-rich dispersed particles in the epoxy matrix. On addition of more than 8 wt % of the terpolymer, the morphologies of the cured resins changed drastically and showed a tendency to from cocontinuous phases. The toughening mechanism was discussed in terms of the morpho-logical behaviors of the modified epoxy resin systems. © 1993 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1993.070481020
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