Biodegradable films based on chitosan and defatted Chlorella biomass: Functional and physical characterization

Biodegradable films based on chitosan, glycerol, and defatted Chlorella biomass (DCB) were prepared and characterized in terms of thermal stability, mechanical, water barrier, and optical properties. Increasing DCB content from 5 to 25 wt% increased tensile strength of chitosan films by 235%. The incorporation of DCB decreased both moisture content and swelling degree of chitosan/defatted Chlorella biomass (Cs/DCB) films. Furthermore, increasing the content of defatted algal biomass decreased light transmission and reduced water vapor permeability of composite films by more than 60%. As confirmed by scanning electron microscopy and Fourier transform infrared analysis, such improvement in functional and physical properties is mainly due to the homogeneous and uniform distribution of DCB into the polymeric matrix along with the establishment of strong hydrogen bond interactions between chitosan and algal biomass constituents. Moreover, Cs/DCB composite films showed more than 50% of degradation in 60 days soil burial test.

Automated summary

Biodegradable films based on chitosan, glycerol, and defatted Chlorella biomass were prepared and characterized, showing that increasing the content of defatted algal biomass improved mechanical properties but reduced water barrier and optical properties of the films. Through microscopy and spectroscopy analysis, the enhancement in properties was attributed to the uniform distribution of DCB and the establishment of hydrogen bond interactions between components.