Polymerization of five‐, six‐, and seven‐membered ring lactams by using metallic potassium or metallic aluminum alkylate as catalyst and certain N ‐acyl lactams or diphenyl ketene as initiator
1966; Inderscience Publishers; Volume: 4; Issue: 2 Linguagem: Inglês
10.1002/pol.1966.150040205
ISSN1542-9350
Autores Tópico(s)Carbon dioxide utilization in catalysis
ResumoAbstract Polymerization of five‐, six‐, and seven‐membered lactams by metallic potassium or MAlEt 4 (where M is Li, Na, or K) as a catalyst and N ‐acyl lactam or diphenylketene as an initiator was carried out at temperatures below 80°C. By using MAlEt 4 instead of a metallic potassium catalyst in the polymerization of α‐piperidone the propagation was continued until the reduced viscosity of polymer reached a value of 0.9. The polymer obtained has a film‐forming ability. The experimental results obtained in the gasometry suggest that MAlEt 4 reacts with lactam to form such a complex of the type magnified image (where M is Li, Na, or K and X is an ethyl or 2‐oxo‐alkylene‐imine group). The resulting complexes are considered to increase the solubility of catalyst and also to protect the polymer endgroups from side reactions by stabilizing the alkali metal as the complex. In addition, the mode of action of diphenylketene as an initiator was revealed by the facts that the corresponding N ‐diphenylacetyl lactam was obtained from the reaction of diphenyl ketene with lactam and N ‐diphenylacetyl lactam itself was useful for the polymerization of α‐piperidone.
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