Eco-friendly starch-nanocellulose bio-nanocomposite films with improved structure-property interactions

Area of Science:

• Materials Science
• Polymer Science
• Biomaterials Engineering

Background:

• Growing environmental concerns necessitate sustainable alternatives to petroleum-based polymers.
• Starch-nanocellulose bio-nanocomposites offer a biodegradable solution for material applications.
• Nanocellulose reinforcement is explored to enhance the properties of thermoplastic starch.

Purpose of the Study:

• To fabricate and characterize starch-nanocellulose bio-nanocomposite films.
• To evaluate the impact of varying nanocellulose fiber loading on material properties.
• To assess the potential of these composites as environmentally benign materials for packaging.

Main Methods:

• Fabrication of composite films using solution-casting and thermoplastic starch matrix.
• Incorporation of nanocellulose derived from filter paper via sulfuric acid hydrolysis.
• Characterization techniques included water uptake, tensile testing, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and UV-vis spectroscopy.

Main Results:

• Increased nanocellulose content reduced water uptake and moisture absorption due to reduced free volume and enhanced hydrogen bonding.
• Morphological observations showed improved film continuity and reduced cracking with nanocellulose addition.
• Enhanced thermal stability (TGA), increased crystallinity (XRD from 32% to 60%), and improved mechanical properties (tensile strength, Young's modulus) were observed.

Conclusions:

• Starch-nanocellulose bio-nanocomposites exhibit enhanced strength, thermal resistance, and barrier properties.
• The addition of nanocellulose significantly improves the physicochemical and mechanical characteristics of thermoplastic starch.
• These bio-nanocomposites show considerable potential as sustainable and biodegradable materials for packaging applications.