Stretchability and Melt Strength Enhancement of Biodegradable Polymer Blends for Packaging Solutions

Area of Science:

• Polymer Science
• Materials Science
• Sustainable Materials

Background:

• Biodegradable polymers are environmentally friendly but often lack the stretchability for demanding applications like flexible films and FIBC bags.
• Current biodegradable blends, such as poly(butylene adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA), require improved mechanical properties for wider industrial use.

Purpose of the Study:

• To enhance the stretchability and mechanical properties of 80% PBAT/20% PLA biodegradable polymer blends.
• To investigate the effectiveness of reactive extrusion with radical initiators and chain extenders in improving blend performance.

Main Methods:

• Reactive extrusion was employed using a batch mixer and twin-screw extruder.
• Dicumyl peroxide (DCP) as a radical initiator and maleic anhydride (MA) or glycidyl methacrylate (GMA) as chain extenders were utilized.
• Films were produced via cast extrusion, and properties were analyzed using differential scanning calorimetry and scanning electron microscopy.

Main Results:

• Addition of 0.1% wt. DCP significantly increased elongation at break by 200% and tensile strength by 44%.
• Enhanced miscibility between PBAT and PLA components was observed, along with increased shear and complex viscosity (38% and 85%, respectively).
• Reactive extrusion improved phase dispersion, interfacial adhesion, and molecular weight, leading to better melt strength and elasticity.

Conclusions:

• Reactive extrusion is an effective method for improving the stretchability and mechanical properties of PBAT/PLA blends.
• The enhanced properties enable the use of these biodegradable polymers in applications previously limited by their flexibility, such as woven FIBC bags and films.
• This research contributes to the development of more sustainable and high-performance biodegradable materials.