Exploring modification on the improved compatibilization nanofibrils of cellulose in poly (lactic acid) bionanocomposites

CARLOS RODRÍGUEZ; NORMA B. D'ACCORSO; NANCY LIS GARCIA

Congreso; 9th World Congress on Biopolymers & Bioplastics August 26-27, 2019 London, UK; 2019

The depletion of fossil energy and growing environmental concerns have increasingly increased interest in eco-efficient and high-technology biologically based materials. Unfortunately, the thermomechanical performance of most renewable polymers is generally lower compared to traditional petroleum-based polymers, so new trends are oriented towards the improvement of these materials with the use of natural nanofillers. Recently, nanocellulose has aroused interest among researchers, as an optimal reinforcing material to improve the deficient physical properties of natural polymers. However, due to the hydrophilic nature of the cellulosic fibers it is difficult to disperse them in hydrophobic matrices such as polylactic acid (PLA). Nanofibrils (NFC), were extracted from the Tacuara Cane (a type of Argentine Bamboo) previously delignified and bleached, through a green process, ending with a high-pressure homogenization. Low molecular weight PLA was modified in its terminal groups to successfully graft onto NFC. Finally, the nanohybrids (PLABz-g-NFC) were incorporated into a commercial PLA matrix by a casting process with three different contents (PLABz-g-NFC at 2%, 3% and 5%) forming interesting films. The thermal analyzes showed an increase in the decomposition temperature as the proportion of the nano-charge was increased. On the other hand, the DSC showed differences in the times of crystallization and fusion of the materials, besides it caused notable differences in their mechanical behavior (modulus and tension at break). All these results improved any previously presented blends. The resulting films are transparent, stable and with proven properties that enhance it as promising materials for different uses in the cosmetic industry, packaging, among others.