MISCIBILITY OF CARBOXYLATED AND SULFONATED POLYSTYRENE IONOMERS WITH POLYAMIDES-66, POLYAMIDES-610 AND POLYAMIDES-11

Differential scanning calorimetry (d.s.c.) of blends of polystyrene ionomers and polyamide-66 shows that lithium sulfonate groups are more effective than lithium or sodium carboxylate groups in enhancing the miscibility between this polyamide and polystyrene. The miscibility between aliphatic polyamides and the polystyrene ionomer containing 9.8 mol% lithium sulfonate groups decreases as the amide content of the polyamide decreases. Thus, while blends of this ionomer with polyamide-66 and polyamide-610 (PA-610) appear miscible by d.s.c., the blends with polyamide-11 (PA-11) show evidence of some phase separation. Dynamic mechanical measurements of the 50:50 blends of this ionomer with PA-610 and PA-11 confirm the one-phase and two-phase behaviour of these blends, respectively.