Desenvolvimento de membranas de bionanocompósitos de PLA/argila e de (PBAT/PLA)/argila.

Abstract

PLA/clay and (PBAT/PLA)/clay bionanocomposites were obtained by melt intercalation and their membranes were produced by solvent evaporation technique. It was used clay without organophilization (UC) and organophilized (TC) with a mixture of three organic intercalants to make it chemically compatible with the polymeric matrix. The results from TG and DSC indicated that the intercalants showed good thermal stability at processing temperatures of the polymeries matrix. By XRF, XRD and FTIR it was verified the efficiency of incorporation of intercalating clay, making it organophilic. The XRD patterns of PLA/UC and (PBAT/PLA)/clays bionanocomposites suggested the formation of partially exfoliated structures. However, the PLA/TC clay bionanocomposites indicated the formation of intercalated structures. By DSC, it was observed that the addition of clay has led to the appearance of double melting peaks in the PLA bionanocomposites and an increased content of UC clay delayed the onset of cold crystallization temperature of the PBAT/PLA bionanocomposites. From the XRD results, it was observed changes occurred in crystallinity of the membranes. It was verified also from the XRD patterns of the membranes obtained PLA/UC clay and TC clay the possible formation of exfoliated/partially exfoliated structures. The morphology of the membrane was observed by SEM and it was verified that the clay favored the formation of porous membranes obtained from the PLA and PBAT/PLA blends bionanocomposites. The tensile tests have suggested that membranes obtained from the PBAT/PLA blends are less rigid than the PLA membranes.