Cellulose nanocrystal driven microphase separated nanocomposites: Enhanced mechanical performance and nanostructured...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Cellulose nanocrystals (CNCs) offer potential for reinforcing polymer matrices.
• Achieving homogenous dispersion and strong interfacial adhesion in hydrophobic polymers remains a challenge.
• Surface modification of CNCs is crucial for compatibility with hydrophobic matrices.

Purpose of the Study:

• To graft hydrophobic polymers onto CNCs to improve dispersion and adhesion in polymer matrices.
• To investigate the impact of modified CNCs (MCNCs) on the thermal and mechanical properties of PBA-co-PMMA copolymers.
• To explore the relationship between morphology and mechanical performance in MCNCs/PBA-co-PMMA nanocomposites.

Main Methods:

• Grafting poly(methyl methacrylate) (PMMA) and poly(butyl acrylate) (PBA) onto CNCs.
• Characterization of modified CNCs (MCNCs) for thermal stability, surface properties, and morphology.
• Fabrication and mechanical testing of MCNCs/PBA-co-PMMA nanocomposites.
• Analysis of nanocomposite morphology using techniques like micro-phase separation observation.

Main Results:

• Successful hydrophobic surface modification of CNCs was achieved.
• Modified CNCs (MCNCs) exhibited enhanced thermal stability.
• Nanocomposites with 7 wt% MCNCs/PBA-co-PMMA showed a >25-fold increase in Young's modulus and a 3-fold increase in tensile strength.
• A distinct micro-phase separated morphology was observed in the nanocomposites.
• Mechanical properties correlated with the observed organized morphology and glass transition temperatures.

Conclusions:

• Hydrophobic modification of CNCs effectively enhances their compatibility with PBA-co-PMMA copolymers.
• MCNCs act as efficient reinforcing agents, significantly improving the mechanical performance of thermoplastic elastomers.
• The observed micro-phase separated morphology is key to the enhanced properties of the nanocomposites.
• This study opens avenues for utilizing MCNCs in advanced polymer composite applications.