Copolyamides of nylon‐4,6 and nylon‐4,T

Copolyamides of nylon‐4,6 and nylon‐4,T were prepared by a two‐step method: (1) a prepolymerization in an autoclave (40 min at 210°C) and (2) a postcondensation in the solid state (4 h, 260°C). On these materials was studied the melting behavior with DSC, the crystalline structure with WAXS, the water absorption, and the mechanical properties with a torsion pendulum. In these copolyamides the order was found to remain high, but the crystalline structures of ‐4,6 and ‐4,T were not isomorphous. The torsion moduli increased with ‐4,T content both at RT and at 140°C.