Funcionalização de montmorilonita com líquidos iônicos e aplicacão em sistema polimerico PBAT/PLA

Abstract

The environmental impact generated by fossil polymers encourages the development of new materials with characteristics that mitigate such damage. In this context, biopolymers stand out for their current progress and their studies that aim to improve their properties, such as, in this case, the incorporation of fillers. In this work, composite films were obtained by the casting method from the commercial biopolymer blend Ecovio® C2224, composed of Poly(butylene adipate co-terephthalate) and Poly(lactic acid) (PBAT / PLA), and natural montmorillonite clay functionalized with ionic imidazole liquids with three types of alkyl chains: butyl, octyl and dodecyl. Different proportions (0, 2.5 and 5% w / w) between the functioning clays and the Ecovio® blend were obtained in films and their physical-chemical properties evaluated by thermogravimetry (TGA), infrared spectroscopy (FTIR), diffraction of X-ray (XRD) and mechanical traction tests. Infrared spectroscopy (FTIR) analyzes confirmed the functionalization of clays and X-ray diffraction (XRD) validated the increase in interplanar space (d001) for all functionalized MMT in relation to the heat treated sample, however the expansion was not proportional to the number of carbons in the alkyl-imidazolium chain. For composites, XRD and FTIR analyzes suggest total exfoliation in films containing calcined and butyl chain MMT and intercalation profiles for octyl and microcomposite for dodecyl The TGA results indicated that the functionalized clays acted as a thermal barrier according to the degree of interaction between matrix/filler and the proportion of clay. With the exception of films obtained with functionalized clay with dodecyl, films obtained with the proportion of 2.5% of functionalized clays showed better results in traction and elastic modulus compared to pure blend. It is estimated that natural MMTs lack processing in order to mitigate adverse effects of their contaminants. Despite the low cation exchange capacity and its influence on the intercalation of LI, it was possible to confirm the functionalization of MMT. The casting method was efficient and the proportions of 2.5% and 5% inferred significant relative changes, with emphasis on films with greater interaction between load / matrix. It is considered that the increase in the carbon chain was due to the greater waterproofing of MMT, reducing the load / matrix interaction. Finally, it is concluded that the PBAT / PLA blend (Ecovio) can have its thermal and mechanical properties improved with the use of natural MMT functionalized with LI based on alkyl imidazolium.