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 a-crystalline form of thermoplastic is thermodynamically more stable than the g-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.

POLYAMIDE (PA 66) membranes were prepared with immersion precipitation via phase inversion from mixtures of polyvinylpirrolidone (PVP) and ammonium oxalate (OX) as constant additives and acetic acid, acetone, formamide, and water as variable additives. The formic acid and pure water were employed as solvent and nonsolvent, respectively. The influences of additives on structure and permeation properties of the membranes were analyzed by scanning electron microscopy (SEM) technique and separation expriments using milk as the feed. In general the addition of water and formamide in the casting solution slightly improves the flux without a pronounced effect on the retention of protein. This behaviour is due to instantaneous demixing (for water) and swelling mechanism (for formamide). When acetone was added to the casting solution, flux was lower and rejection was higher in comparison with the addition of water and formamide. This is due to the establishment of hydrogen bonding between acetone and POLYAMIDE. The addition of acetic acid results in lower flux and higher retention due to delay demixing.