Crystalline and amorphous orientation of polypropylene/nylon 6 blend filaments

The structures of polypropylene/nylon 6 (PP/N6) blend filaments (10 and 20 % wt of N6) made with or without PP-g-MAH as compatibilizer are investigated. The blend filaments produced at the take-up speeds of 300 and 800 m/min were drawn with draw ratio of 3.5 and 2, respectively. Effects of blending of N6 with PP on birefringence, crystalline, and amorphous orientation factors of the composite filaments are studied. The amorphous orientation factor, f(am) of PP was found to increase with the increase in the amount of N6 fraction. The blend filaments behaved like iso-strain materials and most of the force in spinning and drawing was born by the PP phase. The presence of N6 fibrils helped the PP chain molecules to orient in amorphous regions. However, the crystalline factor, f(c) of PP decreased with increase in the nylon fraction. This means that the presence of the crystals of N6 caused a decrease in the orientation of the PP crystals.