Improving the tensile properties of hemicellulose/polylactic acid (PLA) blends prepared by solvent casting

The development of new biopolymers has been explored as an alternative to improve the biodegradability of conventional synthetic plastics, such as those used in the packaging industry. Hemicelluloses are biodegradable polymers extracted from plants that, when combined with other biodegradable polymers, such as polylactic acid (PLA), can be easily processed and satisfy the mechanical requirements for commercial application. Thus, this work seeks a biodegradable blend that combines hemicellulose and PLA properties using solvent casting. The influence of hemicellulose content (5, 10, 15, and 20 wt%) on the thermal and mechanical properties was studied. For that purpose, thermogravimetric analysis and differential scanning calorimetry were applied to determine the thermal stability and crystallinity of the materials. Additionally, water uptake and mechanical tests provided information regarding the mechanical and hygroscopic behavior of the blends due to hemicellulose addition. As a result, the blends presented intermediate thermal stabilities between those of hemicellulose and PLA and increased crystallinities with hemicellulose content. The blends are more flexible and hygroscopic than PLA and more resistant than pure hemicellulose. Given the biodegradable nature of PLA and hemicellulose, these blends have the potential for application in sustainable packaging.