An Effective, Economical and Ultra-Fast Method for Hydrophobic Modification of NCC Using Poly(Methylhydrogen)Siloxane

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Poor compatibility between nanocellulose crystals (NCCs) and polymers hinders NCC's application as a bio-reinforcement.
• Developing methods to improve NCC surface properties is crucial for advanced material applications.

Purpose of the Study:

• To investigate an effective and ultra-fast method for enhancing NCC hydrophobicity.
• To improve the compatibility of NCC with polymers for broader bio-reinforcement applications.

Main Methods:

• Modification of NCC using poly(methylhydrogen)siloxane (PMHS) with reactive -Si-H and hydrophobic -CH3 groups.
• Characterization of modified NCC using Fourier transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), and thermogravimetric analysis (TGA).
• Evaluation of the effect of PMHS to NCC weight ratio and -Si-H content on hydrophobicity and thermal stability.

Main Results:

• Achieved significant improvement in NCC hydrophobicity, increasing water contact angle from 0° to 134° with only 0.0005% PMHS.
• Confirmed covalent grafting of PMHS chains onto NCC via reaction between -Si-H groups and NCC's hydroxyl groups.
• Demonstrated enhanced thermal stability of NCC after PMHS modification.

Conclusions:

• PMHS modification is an effective and rapid method to impart hydrophobicity to NCC.
• The enhanced hydrophobicity and thermal stability of NCC improve its potential as a bio-reinforcement material in polymer composites.
• This approach offers a pathway to overcome compatibility issues and expand NCC applications.