Papers by Author: L.A. Pessan

Abstract: Obtaining membranes from polymer nanocomposites have attracted interest of researchers because they use low levels of charge for improvement in barrier properties. In this study, membranes from poly (imide ether) (PEI) and poly (sulfone ether) (PES) were produced by the solvent evaporation technique, using as solvent: chloroform to PEI and dimethylformamide (DMF) to PES; and the clay Brasgel PA was used as load. The results showed that, by XRD, PEI membranes have apparently a structure of micro-composites and / or interleaved structure. Those obtained with PES had an exfoliated structure and / or partially exfoliated one. However, for the composition of PES with 5% clay, there was a small shoulder, therefore demonstrating perhaps an intercalated structure and/or an exfoliated part. By SEM, it was observed that all the membranes are apparently dense, but the behavior is differentiated by changing the matrix of the membranes.

Abstract: The improvement in the properties of nanocomposites is achieved with a load volume fraction of up to 10% due to the very high ratio of the load aspect. Moreover, they have the advantage of being processed with conventional equipment and techniques (extrusion, injection, etc.) used for polymers. In order for the clay to be uniformly dispersed in the polymer and there to be good interaction with the polymer matrix, superficial treatments of the clays with organic salts are essential for it to become organophilic, and, thus the material obtained has better performance. In this study, it was evaluated the influence of two speeds (100 and 200 rpm) of processing and thermo mechanical properties of nanocomposites with 3% of bentonite clay prepared with two speeds and two threads. The nanocomposites showed better properties as compared to properties of polyamide 6, especially the samples heated at screw speed of 100 rpm.