Biodegradable, Stretchable and Transparent Plastic Films from Modified Waterborne Polyurethane Dispersions

Area of Science:

• Materials Science
• Polymer Chemistry
• Environmental Science

Background:

• Waterborne polyurethane dispersions offer environmentally friendly polymer system development.
• Aliphatic polyols enhance biocompatibility and biodegradability of polyurethane materials.
• Polyvinylpyrrolidone (PVP) is a versatile polymer with various applications.

Purpose of the Study:

• To fabricate biodegradable, flexible, and transparent plastic films.
• To investigate the properties of hybrid films made from waterborne aliphatic polyester polyurethane (PU) and polyvinylpyrrolidone (PVP).
• To evaluate the mechanical stability and biodegradation of the developed hybrid films.

Main Methods:

• Fabrication of hybrid films by mechanical homogenization of PU suspension and PVP in water.
• Casting films with varying concentrations of PVP.
• Characterization of film properties including hydrophobicity, stretchability, transparency, and mechanical stability through wet-dry cycles.
• Assessment of biodegradability using a 28-day biochemical oxygen demand (BOD) test.

Main Results:

• Hybrid films containing 50 wt.% PVP (PU/PVP_50/50) exhibited hydrophobicity, stretchability, and high transparency.
• The PU/PVP_50/50 films were ductile beyond 100% strain, contrasting with brittle PVP.
• Mechanical properties remained stable after repeated wet-dry cycles, with full recovery upon drying.
• Extensive biodegradation was confirmed for the PU/PVP_50/50 hybrid film via BOD testing.

Conclusions:

• A simple and effective method for producing biodegradable, ductile, and transparent films was developed.
• The hybrid PU/PVP_50/50 films possess desirable properties for diverse applications.
• Potential applications include agricultural mulches, food and pharmaceutical packaging, and the biomedical field.