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Soluble polymer-supported catalysts containing pendant quaternary onium salts for the addition reaction of oxiranes with carbon dioxide (1995)

Nishikubo, Tadatomi ; Kameyama, Atsushi ; Yamashita, Jun ; [weitere]

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part A: Polymer Chemistry 33 (1995), S. 1011-1017

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ISSN: 0887-624X

Schlagwort(e): soluble polymer-supported onium salt ; polymer-supported catalytic ; synthesis of cyclic carbonate ; addition reaction ; oxirane ; carbon dioxide ; Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The addition reaction of oxiranes (15a-d) with carbon dioxide (CO2) was carried out using 1 mol % of soluble polymer-supported quaternary onium salts as catalysts under atmospheric pressure. The reaction of 15a-d with CO2 proceeded very smoothly to give the corresponding five-membered cyclic carbonates (16a-d) in high yields at 90-100°C. The catalytic activity of the soluble polymer-supported quaternary onium salts was strongly affected by the following factors: kind of reaction solvent, degree of introduction of the pendant onium salt residues in the polymer chain, and type of alkyl group on the onium salts due to the balance between lipophilicity and steric hindrance of the onium salt residue. Furthermore, these soluble polymer-supported quaternary onium salts were found ordinarily to have higher catalytic activity than low molecular weight quaternary onium salts under the same reaction conditions. It was also found that the rate of reaction was proportional both to catalyst concentration and to oxirane concentration. © 1995 John Wiley & Sons, Inc.

Zusätzliches Material: 7 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/pola.1995.080330702

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Digitale Medien

Toughening of aromatic diamine-cured epoxy resins by modification with hybrid modifiers composed of N-phenylmaleimide-styrene copolymers and N-phenylmaleimide-styrene-p-hydroxystyrene terpolymers (1995)

Iijima, Takao ; Suzuki, Norio ; Fukuda, Wakichi ; [weitere]

New York, NY [u.a.] : Wiley-Blackwell

Polymer International 38 (1995), S. 343-352

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ISSN: 0959-8103

Schlagwort(e): epoxy resin ; p,p′-diaminodiphenyl sulphone ; modification ; influence of hybrid modifier compositions ; fracture toughness ; Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: 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.

Zusätzliches Material: 6 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/pi.1995.210380405

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