| Abstract: | The radical-initiated copolymerization of carbon monoxide and ethylenimine in the presence of ethylene was studied quantitatively. Carbon monoxide copolymerized with difficulty with ethylenimine with α,α′-azobisisobutyronitrile as radical initiator. In the presence of a small amount of ethylene, however, a remarkable amount of crystalline powdery poly-β-alanine (nylon 3) was obtained. The crystalline copolymer, which mainly consists of nylon 3 and contains a small amount of nylon 5 and other substances of higher homologous nylon structure, was obtained in the presence of a large amount of ethylene. This copolymer scarcely contained any ketone structure. Increasing the total feed of the equimolar mixture of the monomers increased the conversion of total monomer and nylon 3 content in the copolymer formed. The effect of increasing carbon monoxide content in this system was to increase both the conversion and the nylon 3 content in the copolymer. In both cases the copolymers were almost identical with nylon 3. Increased ethylene content in the monomer feed, however, increased the conversion and the content of higher homologous nylon structures, such as nylon 5 and 7. From the results it was concluded that ethylene was involved not only in the propagation reaction but also particularly in the initiation reaction. |
