Effect of Polyamide 6 on Crystalline Structure of Polymer in PVDF-Nanoclay Nanocomposite

Abstract

The effect of nanocaly on crystalline structure of poly(vinylidene fuoride), PVDF, and the morphology of the resulting nano-composite were investigated using different characterization techniques. The presence of 3wt% Cloisite 30B in PVDF matrix results in 11 fold increase in the percentage of beta crystalline content of the polymer. This was found to be attributed to the epitaxial effect of the clay surface. The beta crystalline content of the pure polymer (6%) was raised to 68% in the composite. Addition of 5wt% polyamide 6 (PA6) improved dispersion of nanoclay which led to augmentation of the viscosity and displacement of the crossover frequency of the compatibilized composite towards lower frequencies. However, due to stronger affnity of the PA6 towards organically modifed clay the epitaxial effect of the clay on crystalline structure of PVDF was totally eliminated. The reduction of viscosity in incompatibilized nanocomposite was attributed to reduced number of PVDF chain entanglements in the presence of nanoclay. Meanwhile, increase in viscosity and displacement of crossover frequency towards lower frequencies were attributed to formation of clay-PA nanoparticles and PVDF-polyamide 6 interactions. It is expected that the presence of polyamide 6 promotes the formation of oriented-beta crystals in PVDF, which in turn improves the piezoelectric properties of the polymer.

Keywords

• poly(vinylidene fluoride)
• nanoclay
• pa6
• beta crystal
• rheometry