A mechanochemical approach for synthesizing almond shell nanoparticles and their potential application on the enhancement of polylactic acid film properties

The utilization of biopolymers as a packaging material has received enormous attention, owing to the arising pressure on global warming and environmental pollution. Polylactic acid (PLA) is identified as a promising biopolymer with good processability amidst other biopolymers. However, due to its poor barrier property and brittle nature, its use is limited. To alleviate the properties of polymer composites, plasticization and reinforcement with nanoparticles are carried out in this study. Nanoparticles derived from naturals resources (almond shell wastes) are utilized for the present research due to the ecological concerns associated toward the usage of synthetic nanoparticles. Almond shell nanoparticles with an average particle size of 197 nm were prepared by ball milling and then ultrasonication. The influence of plasticizers, such as glycerol, sorbitol, polyethylene glycol, clove oil and polycaprolactone on the properties of biodegradable PLA films was investigated. The results revealed that PLA films blended with 10% (by w/w) naturally derived clove oil improved the elongation by 377.19% and the tensile strength up to 19.75 MPa. The PLA composite films with varied proportions of almond shell waste nanoparticles (0.25-1.0% by wt) were developed. At optimum loading, the tensile strength of PLA/0.75% (by wt) nanoparticle film increased to 25.09 MPa, and its water vapor permeability was reduced to 0.25 x 10(-10) g pa(-1) s(-1) m(-1) with the addition of 1% filler. The PLA films incorporated with nanoparticles displayed low transparency, increased water solubility and biodegradability compared to a neat PLA film. The results obtained demonstrated that the PLA developed, using almond shell wastes, is a better alternative to synthetic plastics in the packaging industries. [GRAPHICS] .

Automated summary

The utilization of biopolymers as packaging materials has attracted attention due to environmental concerns. This study focused on improving the properties of polylactic acid (PLA), a promising biopolymer, by plasticization and nanoparticle reinforcement. Almond shell waste nanoparticles were used for their ecological benefits. The results showed that PLA films blended with naturally derived clove oil improved elongation and tensile strength. PLA films with almond shell waste nanoparticles exhibited reduced transparency, increased water solubility, and improved biodegradability compared to neat PLA films. This study suggests that PLA developed using almond shell waste could serve as a better alternative to synthetic plastics in the packaging industry.