Bionanocomposite films based on plasticized PLA-PHB/cellulose nanocrystal blends

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Poly(lactic acid) (PLA) is a biodegradable polymer with potential for food packaging.
• Improving PLA's mechanical properties, processability, and barrier characteristics is crucial for its wider application.
• Bionanocomposites offer a sustainable route to enhance polymer performance.

Purpose of the Study:

• To develop optically transparent, plasticized poly(lactic acid) (PLA) based bionanocomposite films for food packaging.
• To enhance the properties of PLA by incorporating poly(hydroxybutyrate) (PHB) and cellulose nanocrystals (CNCs).
• To evaluate the processability, thermal stability, mechanical performance, and biodegradability of the developed films.

Main Methods:

• Melt blending of PLA with acetyl(tributyl citrate) (ATBC) as a plasticizer and poly(hydroxybutyrate) (PHB).
• Addition of cellulose nanocrystals (CNCs) or modified CNCs to improve thermal stability and interactions.
• Characterization of film properties including optical transparency, flexibility, oxygen barrier, UV blocking, and disintegration in compost.

Main Results:

• Plasticized PLA-PHB blends with 15wt% ATBC yielded flexible films.
• Addition of 5 wt% CNCs improved the thermal stability of PLA-PHB blends.
• PLA-PHB-CNCs-ATBC films exhibited enhanced oxygen barrier, stretchability, and UV blocking.
• All bionanocomposite films showed appropriate disintegration in compost.

Conclusions:

• Optically transparent, plasticized PLA-based bionanocomposite films with enhanced properties were successfully prepared.
• The combination of ATBC and CNCs significantly improved the interaction between PLA and PHB, leading to better performance.
• These bionanocomposite films are promising candidates for biodegradable food packaging applications.