Melt-blended PLA/curcumin-cross-linked polyurethane film for enhanced UV-shielding ability

Biomass films with ultraviolet (UV)-shielding ability have attracted considerable attention. Curcumin was introduced into castor oil-based polyurethane (CCPU) as a chain extender, which was melt with polylactic acid (PLA) as a reinforcement to obtain biomass UV-shielding film. The excellent UV absorption and antioxidant qualities of curcumin contributed to the impressive UV-shielding capacity (97.6% UV radiation absorption) and antioxidant (51% free radical scavenging) of PLA/CCPU-20 film. In the scanning electron microscopic images of film fracture, the mixing of CCPU elastomer into the PLA matrix caused the blend films to exhibit significant toughening fracture characteristics compared to the pure PLA film. The excellent thermal stability, low water swelling degree, and low water solubility of PLA/CCPU blend films were maintained after CCPU was added to the PLA matrix. Therefore, the PLA/CCPU blend films can be considered as a potential packaging material because of its favorable UV-shielding properties and film stability.

Automated summary

Curcumin was incorporated into castor oil-based polyurethane (CCPU) as a chain extender and melt with polylactic acid (PLA) to obtain a biomass UV-shielding film. The film showed impressive UV-shielding capacity (97.6% UV radiation absorption) and antioxidant activity (51% free radical scavenging) due to the excellent UV absorption and antioxidant qualities of curcumin. The addition of CCPU to the PLA matrix enhanced the toughening fracture characteristics and maintained the thermal stability, low water swelling degree, and low water solubility of the blend films. Therefore, the PLA/CCPU blend films are considered as potential packaging materials with favorable UV-shielding properties and film stability.