Chemically Functionalized Cellulose Nanocrystals as Reactive Filler in Bio-Based Polyurethane Foams

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Cellulose nanocrystals (CNCs) offer potential as reinforcing fillers due to their mechanical strength.
• The inherent hydrophilicity of CNCs limits their compatibility and dispersion in hydrophobic polymer matrices.
• Functionalization strategies are crucial for integrating CNCs into polymer systems effectively.

Purpose of the Study:

• To develop a novel method for enhancing bio-based polyurethane foams (PUFs) using functionalized CNCs.
• To overcome the hydrophilicity challenge of CNCs by grafting bio-based polyols onto their surface.
• To investigate the impact of CNC-grafted-biopolyol as a reactive filler on PUF properties.

Main Methods:

• Surface functionalization of CNCs with bio-based polyols via silane coupling agents.
• Synthesis and characterization of CNC-grafted-biopolyol.
• Incorporation of the functionalized CNCs as reactive fillers in bio-based PUF formulations.
• Evaluation of grafting efficiency using FTIR and TGA.
• Comprehensive analysis of PUF morphology, thermal stability, mechanical properties, and hydrophobicity.

Main Results:

• Successful synthesis of CNC-grafted-biopolyol using silane chemistry.
• Demonstrated effective grafting of polyols onto CNC surfaces.
• Enhanced thermal stability and mechanical properties of PUFs containing the functionalized CNC filler.
• Significant influence of CNC functionalization on the morphology of the resulting PU foams.

Conclusions:

• CNC-grafted-biopolyol serves as a successful reactive filler for bio-based PUFs.
• Surface modification of CNCs is key to improving their compatibility and performance in polymer composites.
• The developed approach offers a promising route for creating high-performance, sustainable bio-based materials.