Dual effects of compatibilizer on the formation of oriented ribbon-like dispersed phase domains in polystyrene/polyamide 6 blends

Polymer blends with oriented ribbon-like dispersed phase were prepared via tape extrusion. Two specially designed compatibilizers, one being non-reactive and another reactive, were used to examine their influence on the formation of oriented ribbon-like dispersed phase in polystyrene (PS)/polyamide 6 (PA6) blend. Results show that both compatibilizers can decrease interfacial tension and produce vinculum effect to strengthen the deformation of dispersed phase. Moreover, the stretching force of tape extrusion pushes the compatibilizer molecules towards the tips of dispersed phase causing a non-uniform distribution along the surface of dispersed phase. At a low loading concentration of compatibilizer, the deformed dispersed phase particles can connect each other from their middle part and merge into long and even endless ribbons. However, when the loading of compatibilizer exceeds a certain level, the formation of ribbon-like dispersed phase will be impeded because all surfaces of dispersed phase are completely covered by the compatibilizer so that the coalescence of dispersed phase cannot occur.