Design and Development of High-Performance Bio-Based Thermoplastic Polyurethane (TPU) Nanocomposites Enabled by...

Area of Science:

• Materials Science
• Polymer Science
• Sustainable Materials

Background:

• The food packaging industry seeks sustainable alternatives to commodity polymers.
• Thermoplastic polyurethane (TPU) offers desirable properties but lacks optimal barrier performance.
• Renewable nano-fillers like cellulose nanocrystals (CNCs) can enhance polymer functionalities.

Purpose of the Study:

• To develop and characterize bio-based TPU nanocomposites using silane-modified cellulose nanocrystals (Si-O-CNC).
• To evaluate the impact of Si-O-CNC on the thermal, mechanical, rheological, wettability, and barrier properties of TPU.
• To assess the potential of these nanocomposites as sustainable food packaging materials.

Main Methods:

• Melt mixing of TPU with varying Si-O-CNC content (1-5 wt.%).
• Compression molding to produce nanocomposite films.
• Comprehensive characterization including FTIR, morphology, thermal analysis, mechanical testing, rheology, wettability, water vapor permeability (WVP), and oxygen transmission rate (OTR).

Main Results:

• Si-O-CNC incorporation promoted hydrogen bonding and altered TPU microphase separation.
• Improved thermal stability and reduced WVP and OTR were observed at 1-3 wt.% Si-O-CNC.
• Enhanced tensile properties were noted at lower nanofiller loadings, while higher loadings led to aggregation and reduced mechanical performance.

Conclusions:

• TPU/Si-O-CNC nanocomposites demonstrate enhanced barrier properties and mechanical performance, particularly at optimal filler concentrations.
• These bio-based nanocomposites present a promising avenue for developing sustainable and high-performance food packaging.
• The study highlights the potential of renewable nanofillers to improve the functionality of versatile polymers like TPU.