Compatibilization and Toughening of Biodegradable Polylactic Acid/Cellulose Acetate Films by Polyamide Amine Dendrimers

Due to the poor compatibility caused by the large difference in hydrophilicity and interface between polylactic acid (PLA) and cellulose acetate (CA), the blending of the two materials is difficult and the application is limited. To solve this problem, a type of polyamide amine (PAMAM) dendrimer was introduced to modify PLA/CA blends in this work. The results showed that PAMAM could improve the compatibility of PLA/CA blends, promote the distribution of CA and crystallization of PLA. At the same time, adding PAMAM could enhance the mechanical properties of the blend material, and the toughness and tear strength were increased by 551% and 141%, respectively. In addition, the incorporation of PAMAM increased hydrophobicity and oxygen permeability of PLA/CA blends, and the oxygen permeability could be increased by up to three orders of magnitude. Degradation test results showed that the blend exhibited good biodegradability. The overall performance of the PLA/CA blend film was optimal when the content of PAMAM was 3 phr. The biodegradable blend films with excellent performance provided wide application prospect in the food green packaging fields.