Crystallization in modified blends of polyamide and polypropylene

A modified polyamide 6 has been used as compatibilizer in blends of polyami de (PA) and isotactic polypropylene (PP). PA was modified in the molten sta te by trimellitic acid (TMA) and n-octyl glycidyl ether by reactive process ing. NMR and FTIR results show that TMA and the ether reacted with PA. Isot hermal crystallization kinetics of the polymers in neat and blend states ha s been investigated by differential scanning calorimetry. Crystallization b ehavior of the polymers in neat state differs from that in blends. However, tendencies are the same for the constituents. The rate of crystallization is highest in unmodified blends and lowest in neat polymers while intermedi ate in modified blends. An investigation of surface and interfacial tension revealed that both surface tension of modified PA and interfacial tension between modified PA and PP decrease as compared to unmodified PA. These res ults are consistent with optical micrographs that show finer dispersions of particles in modified than in unmodified systems. (C) 2000 Elsevier Scienc e Ltd. All rights reserved.