THERMAL-ANALYSIS OF POLYAMIDE BLENDS AS OBTAINED BY REACTIVE MELT-EXTRUSION - INFLUENCE OF BLEND COMPOSITION ON CRYSTALLIZATION AND MELTINGBEHAVIOR

Polyamide blends composed of PA 46 and PA 6I were melt-mixed using a d ouble-screw extruder, and the obtained compounds were subsequently pro cessed by injection molding. The blend materials obtained were found t o have undergone transamidation processes during the extrusion and inj ection-molding operations which alter the crystallization and melting behavior. The variation in thermal behavior is strongly dependent on t he change in the average sequence length of the crystallizable compone nt in the copolymer formed; it is affected by the compounding and proc essing conditions and by the blend composition. The influence of every melt-processing step on the crystallization and melting behavior of t he blends was investigated by thermal analysis using extruded, injecti on-molded, and solution-prepared blends. (C) 1997 John Wiley & Sons, I nc.