Synthesis and characterization of poly(4-alkyl-4-methyl-2-azetidinone)s

✍ Scribed by Marc Fournier; Robert E. Prud'homme

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 152 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19990315)37:6<761::aid-pola11>3.0.co;2-x

✦ Synopsis

Poly-␤-amides (nylons 3) were synthesized via the anionic polymerization of a series of 4-alkyl-4-methyl-2-azetidinones where the alkyl group is a methyl, ethyl, propyl, butyl, or pentyl. The "non-assisted" polymerization was conducted under vacuum, in the bulk, at 160°C, using potassium 2-pyrrolidonate as catalyst, whereas the "assisted" polymerization was carried in dimethylsulfoxide, at room temperature, using N-acetylpyrrolidinone-2 as activator but it gave no polymer with a propyl or bulkier side group. Side reactions occur in all cases. X-ray spectra showed that poly(4-alkyl-4methyl-2-azetidinone)s are amorphous with propyl, butyl, and pentyl groups, and semi-crystalline with methyl or ethyl substituents. Both semi-crystalline polyamides exhibit an extended planar zigzag conformation, with a fiber identity period along the c axis of 4.9 Å. Glass transition temperatures, melting temperatures, and/or decomposition temperatures are also reported.