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  • 1
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Soluble or insoluble polystyrenes with hydroxyl-containing polyetheramine structures were prepared by the reaction of linear or crosslinked polystyrenes containing haloalkyl, tosyloxyalkyl, or epoxy groups with bis(2-(2-hydroxyethoxy)ethyl)amine(ATEG). The soluble polystyrenes with ATEG residue afforded polymeric alkoxides by the reaction with aqueous NaOH or KOH under two-phase conditions. The introduction of oxygen-containing spacer chains between ATEG residue and the polymer backbone resulted in the formation of cryptand-like alkoxides, in which the counter cations were bound by cooperative coordination of the oxygen donors in the ATEG residue and in the spacers. The soluble and insoluble polymers with ATEG residue exhibited high catalytic activity for the dehydrobromination of 2-bromoethylbenzene with aqueous NaOH or KOH under two-and three-phase conditions, respectively. The extra coordination of the oxygen donors in the spacers resulted in increased catalytic activity.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 939-947 
    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
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  • 3
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1543-1550 
    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
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 26 (1988), S. 305-311 
    ISSN: 0887-6258
    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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  • 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
    Notes: N-Phenylmaleimide (PMI)-N-(p-hydroxy)phenylmaleimide (HPMI)-styrene (St) terpolymers (HPMS), containing pendant p-hydroxyphenyl (HP) groups, were prepared and used to improve the toughness of triglycidyl aminocresol epoxy resin cured with p,p′-diaminodiphenyl sulfone. HPMS was effective as a modifier for the toughening of the epoxy resin. When using 15 wt % of HPMS (1.0 mol % HP unit, Mw 129,000), the fracture toughness (KIC) for the modified resin increased 190% with a medium loss of flexural strength. The toughening of epoxies could be attained because of the cocontinuous phase structure of the modified resins. The decrease in flexural strength was suppressed to some extent by introducing a functional group into the modifier. The toughening mechanism was discussed in terms of the morphological behavior of the modified epoxy resin system. © 1995 John Wiley & Sons, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 60 (1996), S. 37-45 
    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: The effect of matrix compositions on the toughening of bismaleimide resin by modification with N-phenylmaleimide-styrene copolymers (PMS) were examined. The bis-maleimide resin was composed of 4,4′-bismaleimidediphenyl methane (BMI), o,o′-diallyl bisphenol A (DBA), and triallyl isocyanurate (TAIC). The matrix structure was controlled by changing the equivalent ratio of the two allyl components (DBA and TAIC). Morphologies of the modified resins changed from particulate to cocontinuous and to inverted phase structures, depending on the modifier content. The most effective modification for the cured resins could be attained because of the cocontinuous structure of the modified resins. Inclusion of TAIC led to a decrease in the extent of dispersion of the cocontinuous phase, and the optimum matrix structure to improve the toughness was obtained on 20 eq % addition of TAIC. For example, when using 20 eq % of TAIC and 5 wt % of PMS (Mw 303,000), the fracture toughness (Kic) for the modified resins increased 100% at a moderate loss of flexural strength and with retention in flexural modulus and the glass transition temperature, compared to those of the unmodified cured Matrimid resin. © 1996 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 61 (1996), S. 163-175 
    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 aromatic dicarboxylic acids and 1,4-butanediol, were used to improve the toughness of bisphenol-A diglycidyl ether epoxy resin cured with p,p′-diaminodiphenyl sulfone. These polyesters contained poly(butylene phthalate)s (PBP), poly(butylene phthalate-co-butylene isophthalate)s, poly(butylene phthalate-co-butylene terephthalate)s, and poly(butylene phthalate-co-butylene 2,6-naphthalene dicarboxylate)s. All aromatic polyesters used in this study were soluble in the epoxy resin without solvents and were found to be effective as modifiers for toughening the cured epoxy resin. For example, the inclusion of 20 wt % PBP (MW 16,300) led to a 120% increase in the fracture toughness (KIC) of the cured resin with no loss of mechanical and thermal properties. The toughening mechanism was discussed in terms of the morphological and dynamic viscoelastic behaviors of the modified epoxy resin system. © 1996 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0959-8103
    Keywords: epoxy resin ; p,p′-diaminodiphenyl sulphone ; modification ; influence of hybrid modifier compositions ; fracture toughness ; 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: Hybrid modifiers composed of N-phenylmaleimide-styrene copolymers (PMS), and N-phenylmaleimide-styrene-p-hydroxystyrene terpolymers (PMSH) containing pendent p-hydroxyphenyl groups as functionalities, were used to improve the toughness of bisphenol-A diglycidyl ether epoxy resin cured with p,p′-diaminodiphenyl sulphone. The hybrid modifiers were effective in toughening the epoxy resin. When using the modifier composed of 10 wt% PMS (M̄w 313000) and 2.5 wt% PMSH (2.5 mol% p-hydroxystyrene units, M̄w 316000), the fracture toughness (KIC) for the modified resins increased 100% with no deterioration in the flexural properties and the glass transition temperature. The improvement in toughness of the epoxy resins was attained because of the co-continuous phase structure and the improvement in interfacial adhesion. The toughening mechanism is discussed in terms of the morphological characteristics of the modified epoxy resin systems.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 48 (1993), S. 1859-1868 
    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
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  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Letters 1 (1963), S. 225-227 
    ISSN: 0449-2986
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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