Phase behavior and physical properties of injection-molded polyamide 6/phenoxy blends

✍ Scribed by G. Guerrica-Echevarría; J. I. Eguiazábal; J. Nazábal

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 516 KB
• Volume: 72
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19990531)72:9<1113::aid-app1>3.0.co;2-g

✦ Synopsis

Polyamide 6 (PA 6)/poly(hydroxyether of bisphenol A) (phenoxy) blends were obtained by direct injection molding over the whole composition range. Differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and scanning electron microscopy (SEM) showed the almost full immiscibility of the blends and the lack of effect of phenoxy on the crystalline phase of PA 6. The rodlike and fine-dispersed phase of the tensile specimens was strongly deformed during tensile testing, giving characteristic fibrilar structures. The Young's modulus and yield stress showed small deviations from additivity that appeared related mainly to the blendinginduced free-volume change. Despite immiscibility, the ductility behavior was also additive, probably due to the fibrilar morphology. However, the thicker impact specimens gave rise to less oriented larger dispersed phases and to full plane strain conditions that, in opposition to ductility, yielded impact strength values well below linearity.