Nylon 66 Membranes: Influence of polymer concentration on the morphological and transport properties

ALMAZÁN, JORGE E.; ROMERO DONDIZ, ESTELA M.; RAJAL, VERÓNICA B.; CASTRO VIDAURRE, ELZA F.

Amsterdam, The Netherlands

Congreso; International Congress on Membranes and Membrane Processes (ICOM 2011).; 2011

University of Twente

Currently, polyamide membranes are emerging as promising alternatives in food and biotechnology industries because of their resistance to high temperatures, chemical disinfectants, and microbial attack (Heldman 2007). Nylon 66 is an aliphatic polyamide, which  is  presented  as  a semi-crystalline  polymer  that  has  good  thermal  stability  and mechanical strength, and is considered an important engineering thermoplastic (Tohgo, 2001, Murthy 2002).In membrane technology, experimental works showed that the polymer concentration is one of the most important parameters to achieve the desired properties of the membranes. This is because a thicker and selective layer is formed with increasing polymer concentration, which increases the selectivity of certain substances and reduces the flow due to high mechanical resistance offered by the membrane (Murphy, 1995; Pesek, 1994; Saljoughi, 2009).The aim of this work was to synthesize Nylon 66 membranes and to analyze  the effect of polymer concentration in the polymeric solution. Membranes were synthesized by the phase inversion technique through immersion-precipitation, described by Mulder (1991). Polymeric solutions were prepared changing the polymer concentration between 8 and 16% w/w. These membranes were  characterized  by  thickness measurements, scanning  electron microscope  (SEM),  equilibrium  water  content  (EWC),  porosity  (P), pure water flux  (Jw).  Results showed that higher concentration of polymer causes an increase in membrane thickness and a decrease in flow and permeability of pure water. References: · Heldam, D. (2007), Handbook of Food Engineering, 2  Edition, Taylor and Francis Group.· Mulder M, (1991), Basic Principles of Membrane Technolog, Kluwer Academic publishers, London.· Murthy, N. S.; Wang, Z.-G.; Akkapeddi, M. K.; Hsiao, B. S. (2002),  Isothermal crystallization kinetics of nylon 6, blends and copolymers using simultaneous small and wide-angle X-ray measurements, Polymer 43(18), 4905-4913. · Pandey, P., Chauhan R. S. (2001), Membranes for gas separation, Prog. Polym. Sci. 26, 853-893.· Pesek, S.C., Koros W. J. (1994), Aqueous quenched asymmetric polysulfone hollow fibers prepared by dry/wet phase separation, J. Membr. Sci. 88, 1-19.· Saljoughi E., Sadrzadeh M., Mohammadi, T. (2009), Effect of preparation variables on morphology  and  pure  water  permeation  flux  through  asymmetric  cellulose  acetate membranes, J. Membr. Sci. 326, 627-634.· Tohgo, K., Fukuhara, D., Hadano, A. (2001), The influence of debonding damage on a crack-tip  field  in  glass-particle-reinforced  nylon  66  composite.  Compos  Sci  Technol. Composites Science and Technology, Vol, 61, Numb. 8, 1005-1016.