Isothermal crystallization and melting behaviors of nano TiO 2 ‐modified polypropylene/polyamide 6 blends

Titanium dioxide (TiO 2 ) nanoparticles were functionalized with toluene‐2,4‐diisocyanate and then polypropylene/polyamide 6/(PP/PA6) blends containing functionalized‐TiO 2 were prepared using a twin screw extruder. Isothermal crystallization and melting behavior of the as‐prepared composites were investigated using differential scanning calorimetry and wide‐angle X‐ray diffraction. Isothermal crystallization analysis shows that the TiO 2 nanoparticles have two effects on PP/PA6 blends, i.e., it can favor the improvement of crystallization ability and decrease the crystallization rate of PP/PA6 blends. The improvement of crystallization ability is superior over decreasement of crystallization rate of PA6 chains caused by TiO 2 , therefore PA6 in PP/PA6/TiO 2 nanocomposites have higher crystallization rate than that of PA6 in pure PP/PA6 blends, which indicated TiO 2 nanoparticles favored the crystallization of PA6. The TiO 2 nanoparticles show no effects on the equilibrium melting temperature ( T   m 0 ) values of PP phase but decreases the T   m 0values of PA6 phase. In addition, the TiO 2 nanoparticles did not change the crystalline polymorph of PP/PA6 blends basically; however, favored the formation of β‐PP. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers