Mechanical, thermal, rheological assessment of polyamide-6 reinforced composites by addition of lamellar zirconium phosphate

The improvement of properties has been pursued through the addition of an immense variety of fillers in polymers. In this work we studied the effect of lamellar zirconium phosphate (ZrP) on the physico-mechanical properties of polyamide-6 (PA-6). The ZrP was synthesized and incorporated into PA-6 matrix at 1, 2 and 3 wt.%. Structural, thermal, relaxometric, tensile, melt flow and rheologic characteristics were assessed. Thermogravimetry indicated a low influence of the filler on thermal stability. The deconvolution of the melting peaks indicated transformation of the PA-6 alpha to gamma phase and increase in crystallinity degree. Sample with 1 wt.% of ZrP showed an additional peak at higher relaxation time indicating restriction of polymer molecular mobility. By infrared, amine and carbonyl indices evaluation suggested ZrP interfered on the PA-6 hydrogen bonds. The elastic modulus increased slightly for all composition. Melt flow rate decreased with the amount of ZrP. The composite with 1 wt.% of ZrP exhibited the highest storage modulus and shear thinning effect noticed in the complex viscosity.