Desenvolvimento de membranas a partir de blendas de PA6/PEAD/compatibilizantes.

Abstract

The applications of polymers and polymer blends comprise several segments, which stand in application such as in membrane separation processes. Microporous membranes were obtained from of PA6/PEAD and PA6/PEAD/Compatibilizers blends by phase inversion method. It was evaluated the use of PEgAA, PEgMA and the EMA-GMA as compatibilizing agents. The blends were obtained in twin-screw extruder counter-rotate and the material was subjected to dissolution in formic acid. It was used a simple spreading technique on glass and bath immersion-precipitation. It used two temperature conditions for the spreading at 60°C called "hot" and at room temperature (23°C) called "cold". Torque rheometry was used to evaluate the reactivity of the constituents of the blend. The membranes were characterized by FTIR, XRD, SEM and permeate flux. Results by torque rheometry showed reactivity between the three blend compatibilizers and PA6/HDPE. By SEM, the "hot" membranes, in general, presented a surface with a lower amount and small pore size when compared with "cold" membranes. The membranes obtained from blends presented higher permeated flow when compared to pure polyamide, except to the system with PEgAA, which probably presented not interconnected pores. It was found that the permeated flow is proportional to the applied pressure of 2Kgf/cm2 characteristic of microfiltration processes. The "cold" membranes presented permeated flow higher than "hot" membranes. Amoung "cold" membranes the one that presented highest permeate flow was the EMA-GMA, and amoung "hot" membranes, it was the PEgMA. So, for all compositions it was possible to verify that the presence of HDPE and HDPE/compatibiiizer significantly changed their morphology, distribution, uniformity of pores and permeated flow. These characteristics were also influenced by temperature conditions used in the spreading.