Compositions and Methods Related Functionalized Cellulose Nanofibrils

Abstract

Researchers at the University of California, Davis have developed a one-pot synthesis process for producing hydrophobic, bromine-esterified nanocellulose (Br-CNF) that is dispersible in organic solvents, enabling the creation of enhanced polyurethane composites and serving as a versatile platform for precision polymer functionalization.

Full Description

This technology features a one-pot method producing Br-CNF directly from cellulose in organic media followed by ultrasonication. By targeting cellulose hydroxyl groups on crystalline surfaces and converting them into organic-compatible 2-bromopropionyl esters, the process renders the material inherently hydrophobic. The resulting Br-CNF features nanoscale dimensions (~4.6 nm thickness, 29.3 nm width, 1 micron length) and maintains high crystallinity (~48%). Its ability to disperse (>25%) in solvents like DMF, DMSO, chloroform, THF, and toluene unlocks new potential for material science, acting as both a mechanical reinforcement and a site-specific macroinitiator for SI-ATRP (Surface-Initiated Atom Transfer Radical Polymerization).

Applications

• High-performance polyurethane composites with potentially superior durability that could be useful in automotive and aerospace settings. 
• Hydrophobic surfaces and films with tunable wettability for packaging, sensors, and protective layers. 
• Rheology modifiers and viscosity enhancers in organic solvent-based formulations and lubricants. 
• Biobased polymer brushes for advanced functional materials via SI-ATRP grafting. 
• Sustainable, environmentally-friendly, and renewable nanomaterial supply for composites, adhesives, and coatings markets.

Features/Benefits

• Enhances polyurethane tensile modulus (up to 3.2×), strength (up to 3.9×), and strain-to-failure (up to 1.5×). 
• Enables covalent incorporation into polyurethane matrices as a chain extender or polyol. 
• Integrates esterification and disintegration into a one-pot, solvent-compatible process. 
• Overcomes the traditional incompatibility of hydrophilic nanocellulose with non-polar and organic material. 
• Offers tunable rheological properties for effective viscosity modification in organic fluids. 
• Reduces high toxic diisocyanate (MDI) loading required for polyurethane synthesis. 
• Provides a renewable, high-performance alternative to traditional petrochemical filters and modifiers.

Patent Status