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

• Main Authors: Ali Akbar Yousefi, Mohammad Mahdi Salarian
• Format: Article
• Language: fas
• Published: Iran Polymer and Petrochemical Institute 2012-12-01
• Series: علوم و تکنولوژی پلیمر
• Subjects: poly(vinylidene fluoride); nanoclay; PA6; beta crystal; rheometry
• Online Access: http://jips.ippi.ac.ir/article_547_ee12ee5e9f7f2ee35d62ea069b208811.pdf

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.