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  • 1
    Electronic Resource
    Electronic Resource
    Catalytic aminolysis of acrylic copolymers in solution and in the melt. II. Comparison between styrenic and ethylenic copolymers (1992)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 635-641 
    Details
    ISSN: 0887-624X
    Keywords: aminolysis ; catalysis ; mechanism ; kinetics ; tautomeric compound ; melt ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The aminolysis of poly(styrene-co-methyl acrylate) (SMA) by octadecylamine in solution and in the melt has been reported in Part I. We now have studied the aminolysis of poly(ethylene-co-methyl acrylate) (EMA) with the same amine in the melt and compared the two sets of data in this paper. With EMA, the data confirmed and precised the catalytic mechanism proposed in Part I. The best tautomeric catalysts are the ones which form an eight-atom ring structure with the ester and amine groups. With EMA aminolysis is faster than with SMA because of the steric hindrance of phenyl groups in SMA. But EMA aminolysis remains a rather slow reaction. In a corotating twin-screw extruder the conversion was only around 4% at 220°C with a mean residence time of 150 s. It was also shown that the EMA/octadecylamine/catalyst system, like the SMA system, is homogeneous in the molten state at temperatures around 200°C.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1992.080300415
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  • 2
    Electronic Resource
    Electronic Resource
    Catalytic aminolysis of acrylic copolymers in solution and in the melt. I. Mechanism and kinetics (1992)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 625-634 
    Details
    ISSN: 0887-624X
    Keywords: catalysis ; mechanism ; kinetics ; aminolysis ; tautomer ; molten state ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The aminolysis of poly(styrene-co-methyl acrylate) (SMA) by octadecylamine was studied in solution and in the melt at temperatures around 200°C. This reaction is rather slow, so several types of catalysts were tested to accelerate it. The most efficient is 2-pyridone, a compound in tautomeric equilibrium with 2-hydroxypyridine. A mechanism of the catalytic reaction is proposed whereby the tautomeric nature of the catalyst plays a key role in a very important step of the reaction, namely the proton transfer. This mechanism is confirmed by the kinetic data determined in a 1,2,4-trichlorobenzene solution and in the melt. In addition, it was found that the kinetic data obtained in both media are very close, indicating no significant difference of local polarity in the two reaction media. Data also show only a minor effect due to difference in viscosity. Finally, the question of the homogeneity of the molten medium is discussed.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1992.080300414
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    Paper (German National Licenses)
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