ISSN:
0025-116X
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
N-Ethylaziridine (1) was polymerized in water with HCl as initiator and copolymerized with N-(2-hydroxyethyl)aziridine (2). Rapid propagation and termination reactions were observed. The maximum yield increases with the initiator concentration, whereas the molecular weight decreases. This is due to the difference in basicity between the tertiary N-atoms of the two monomers and the tertiary and the terminal secondary N-atoms of the polymers, which causes tranfer and termination reactions. Macrocycles with a side chain on a quaternary N-atom are formed. During the copolymerization, the more basic 1 is preferentially incorporated into the copolymer chain. The copolymerization parameters can be estimated roughly on the basis of basicity considerations: r1 〉 1; r2 〈 1. The ratio of the rate constants (propagation to termination) is lower for 1 than for 2. This is due to the fact that the basicity difference between the monomer and the tertiary N-atoms of the polymer is higher for 1 than for 2. By reaction of thionyl chloride with the copolymers the desired hydrochlorides of the N-(2-chloroethyl) derivatives are obtained. The neutralisation with alkali did not result the free bases, since the products formed are rather due to side reactions.
Zusätzliches Material:
4 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/macp.1982.021830606
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