Synthesis and Characterization of Polyamide-66/Calcium Carbonate Composites

Polyamide-66(PA66)/CaCO3 micro- and nano-composites were prepared using a polymer solution method at filler loading of 0, 1, 2 and 3 weight percent. Nano-size of CaCO3 was synthesized by micro-emulsion technique. The material was characterized by XRD, SEM, FTIR and UV-VIS techniques. XRD results of composites suggested that CaCO3 particles are found in the amorphous phase of the semi-crystalline thermoplastic and α-crystalline form of thermoplastic is thermodynamically more stable than the γ-crystalline forms at room temperature. The uniform dispersion of 1, 2, and 3 wt. % surface modified micro- and nano-CaCO3within PA66 were evidenced from SEM images. FT-IR analysis confirmed the chemical structure of the PA66. Absorption peaks for all required chemical groups were showed in the FTIR spectra: N-H stretch at 3305.52 cm-1, C-H stretch at 2865.02-2936.45 cm-1, Amide-I at 1638.76 cm-1, and Amide-II at 1539.55 cm-1. UV-VIS data showed that the presence of CaCO3 particles in PA66 results in the decrease of energy-band gaps of the composites. In addition, the results showed that incorporation of CaCO3 particles increased the modulus and tensile strength of neat PA66 however decreased its yield and elongation at break.