A. Upadhyay, L.A. Lucia, L. Pal
North Carolina State University,
United States
Keywords: Microfibrillated cellulose, Composite coatings, Water barrier, Oil & grease barrier, Recyclability, Sustainable packaging
Summary:
Microfibrillated cellulose (MFC) has emerged as a promising material in packaging, offering high gas and oil barrier properties. However, its limited water resistance poses challenges for single-use plastic replacements and other applications. This study presents a bilayer composite coating (BCC) system designed to address these limitations, combining a water-resistant top layer with an MFC layer that can maintain recyclability while enhancing barrier performance. The top layer, composed of a non-polar coating including nano clay, forms a hydrophobic interface that effectively resists moisture, while MFC acts as a biodegradable tie layer. Advanced techniques such as SEM, FTIR, and XPS confirmed the effectiveness of the BCC system, preventing intermixing and improving fiber recovery during recycling. The BCC system significantly enhanced air resistance, water vapor transmission rate (WVTR), and oil and grease resistance (OGR), demonstrating its potential for packaging applications by balancing barrier performance and environmental sustainability.