Evaluation of the physicochemical properties of low linear density polyethylene and organophilic montmorillonite nanocomposites obtained by extrusion

ABSTRACT Low density linear polyethylene nanocomposites with organophilic montmorillonite clay (OMMT) from Brazilian source were obtained with the objective of evaluating the physicochemical properties. Nanocomposites obtained by extrusion at the concentrations 2, 2.5, 3, 3.5% and the pure polymer were produced and characterized. The mixtures were injected and characterized. The TGA analyzes showed that the addition of nanoclay considerably increased the thermal stability of the samples, especially the PELBD/OMMT2,0, which increase was of 5.6% compared to White. Through DSC it was found that the samples with nanoclay incorporation suffered no change in melting temperature in relation to the pure sample of LLDPE, however, the incorporation of clay increased the degree of crystallinity of the samples, especially for the LLDPE/OMMT2,5 sample that showed a 9,48 % degree of crystallinity higher than the white one. The flammability results revealed that the LLDPE/OMMT2,0 sample showed a decrease of 38 % in the flame propagation velocity. In the tensile test it was noticed an increase in stiffness of the samples with addition of OMMT compared to the White one, increasing the Young's modulus and decreasing the elongation at fracture with the percentage increase of OMMT. On the other hand, the NMR technique showed that the samples of up to 2,5% of OMMT suggests the formation of an exfoliated nanocomposite.