| 摘要 |
Polyamides are prepared by heating an anhydrous lactam at a temperature below the m.p. of the polyamide to be formed and in the presence of 0.1-10 mole per cent of a lactam salt as catalyst and as cocatalyst 0.1-5 mole per cent of a compound of formula <FORM:1091670/C3/1> where n = 2-10. Lactams specified are those having 3-12 carbon atoms, e.g. e -caprolactam. The lactam salt may be derived from the lactam to be polymerized or from another lactam by reaction with an alkali metal, an alkaline earth metal or aluminium or a hydroxide, alkoxide, hydride, aryl, amide or organic salt thereof. It may be prepared in situ by adding the base to the polymerization mixture. Cocatalysts specified include those in which n equals 2, 3, 4, 5 and 10. The polymerization may be at 25-200 DEG C. |
