| 摘要 |
<p>An improved method for manufacturing poly(hexamethylene adipamide), i.e. nylon 6,6, by reacting monomethyl adipate with hexamethylenediamine in an approximately equimolar ratio in the presence of water at a temperature of 100 to 165 °C while simultaneous distilling off of a stoichiometric amount of methanol. The resulting aqueous intermediate product is then heated to 200 to 260 °C while distilling off substantially all water at a pressure of 150 to 250 psig (1.03 x 106 to 1.72 x 106 Pa) followed by reducing the pressure to atmospheric pressure and increasing the temperature to 270 to 280 °C to polycondense the distillate residue. Such a process is useful in producing high purity commercial grade poly(hexamethylene adipamide) that advantageously avoids problems caused by N-methylation of the polyamide.</p> |
