H. Kricheldorf, G. Loehden
Dec 1, 1994
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0
Influential Citations
2
Citations
Journal
Macromolecules
Abstract
Three N-(4'-aminobenzoyl)lactams were prepared by condensation of 4-(sulfinylamino)benzoyl chloride with N-(trimethylsilyl)-3-dimethylazetidinone-2, N-(trimethylsilyl)pyrrolidone-2, and N-(trimethylsilyl)azepinone-2. The polycondensation of the N-(4-aminobenzoyl)lactams was studied in various reaction media, such as N-phenylpyrrolidone, diphenyl sulfone, m-terphenyl, or Marlotherm-S, at temperatures ranging from 180 to 400°C. With regard to molecular weights, the best results were obtained in Marlotherm-S at 300 or 35°C (η inh ∼ 1.5 dL/g). The ratio of polycondensation versus polyaddition (by ring opening) was determined by 1 H NMR spectroscopy. Up to 90% polycondensation was found for the β-lactam derivative, along with side reactions limiting the molecular weight. The pyrrolidone- and e-caprolactam-based monomers yielded copolyamides containing 80-95% 4-aminobenzoyl units. The WAXD powder patterns exhibit the typical reflections of semicrystalline poly(4-aminobenzamide) with little influence of the reaction conditions. SEM and TEM showed that aggregates of crystallites looking like shavings were obtained at reaction temperatures ≥ 275°C