Abstract:  Polylaetic acid ( PLA) is a thermoplastie that can be fully degraded into carbon dioxide andwater. Industrially , it is polymerized from lactic acid through multiple reaction steps. PLA possesses bio-eompatibility and environmental friendliness and is employed in the biomedical and food packaging domains. Nevertheless, it has drawbacks such as inferior mechanical properties, poor thermal stability.slow crystallization rate, and high cost. Based on this, the modification studies aimed at amelioratingthese disadvantages are summarized. The modification approaches are mainly accomplished through phys.ical blending, one being blending in the molten state under heating, and the other being blending in solu-tion with the assistanee of mechanical stirring. Judging from the modifieation outcomes, most modifications can fulfill the objective of improving the performance disadvantages of PLA. However, for the solvents involved in solution blending, the majority are toxic solvents, which contradicts the non-toxic andbiocompatible characteristics of PLA and requires attention in praetical research.

Key words:  , polylactie aeid: modification: blending: degradable: food packaging