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  • 1
    Electronic Resource
    Electronic Resource
    Polymer-supported bases. 5. Acetylation of linalool with acetic anhydride using dialkylaminopyridines attached by spacer chains to polystyrene resins (1987)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 25 (1987), S. 77-86 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The acetylation of linalool with acetic anhydride was carried out in the presence of polystyrene-bound aminopyridines and triethylamine. The catalytic activity of the immobilized aminopyridines increased with decreasing percentage of ring substitution and with increasing spacer-chain length. The increased activity is attributed to an increase in the amount of aminopyridine units complexed with acetic anhydride. The acetylation could be successfully conducted by use of a mixture of the immobilized aminopyridines and polymer-supported benzyldiethylamine, which effectively trapped acetic acid formed in the reaction system.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1987.080250108
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  • 2
    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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  • 3
    Electronic Resource
    Electronic Resource
    Polymer-supported bases. 7. Nucleophilic acyl rearrangements catalyzed by polymer-supported aminopyridine or imidazole bases (1987)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 25 (1987), S. 2455-2467 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymer-supported aminopyridine or imidazole catalysts were effective for acyl rearrangements of O-acylated substrates to C-acylated products. Some of the aminopyridine catalysts, which had much higher activity than the imidazole catalyst, exhibited high activity comparable to that of the corresponding soluble catalyst, 4-N, N-dimethylaminopyridine. The activity of the immobilized aminopyridines was studied as a function of the percentage of ring substitution, spacer-chain length, and solvents. The affinity of the substrates for the immobilized catalysts played an important role for the rearrangements. The increased catalytic activity resulted from the increased affinity of the substrates for the catalysts. The activity of the immobilized bases decreased gradually owing to the reaction of the active site with the products as the catalysts were used repeatedly. The treatment of the used catalysts with nucleophiles restored the activity to some extent. The activity decrease can be minimized by shortening a contact time between the catalysts and the products.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1987.080250911
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  • 4
    Electronic Resource
    Electronic Resource
    Polymer-supported bases. IX. Synthesis and catalytic activity of polymer-bound 4-(1-pyrrolidino)pyridine moieties (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2251-2261 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polystyrene-bound 4-(1-pyrrolidino)pyridine moieties were prepared by the reaction of chloromethylated polystyrene resins with pyrrolidinopyridine derivatives containing hydroxyl groups. The supported amines were effective catalysts for acylations of tert-alcohols or enols, acylrearrangements, and diester synthesis from epoxides and anhydrides. Some of the low ring-substituted (8-15%) catalysts exhibited high activity comparable to that of 4-(N,N-dimethylamino)pyridine, though the activity was a little lower than that of 4-(1-pyrrolidino)pyridine. The recovered catalysts can be re-used, except for acyl rearrangements, without significant decrease in activity.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1988.080260819
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  • 5
    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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  • 6
    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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  • 7
    Electronic Resource
    Electronic Resource
    Polymer-supported bases. VI. Synthesis of phosphatidylcholines from cadmium-free L-α-glycerophosphorylcholine impregnated to macroporous polystyrene resins containing dialkylaminopyridine groups (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2291-2293 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1988.080260823
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  • 8
    Electronic Resource
    Electronic Resource
    Soluble polymer-supported catalysts containing pendant quaternary onium salts for the addition reaction of oxiranes with carbon dioxide (1995)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 33 (1995), S. 1011-1017 
    Details
    ISSN: 0887-624X
    Keywords: soluble polymer-supported onium salt ; polymer-supported catalytic ; synthesis of cyclic carbonate ; addition reaction ; 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 (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.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1995.080330702
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  • 9
    Electronic Resource
    Electronic Resource
    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)
    New York, NY [u.a.] : Wiley-Blackwell
    Polymer International 38 (1995), S. 343-352 
    Details
    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
    URL: http://dx.doi.org/10.1002/pi.1995.210380405
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  • 10
    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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