Homogeneously Blending PBAT with Silanized Cellulose for Composite Film: Characterization and Physicochemical...

Area of Science:

• Materials Science
• Polymer Science
• Composite Materials

Background:

• Improving interfacial compatibility between cellulose and poly(butylene adipate-co-terephthalate) (PBAT) is crucial for advanced composite performance.
• Surface modification of biomass-derived fillers like cellulose is key to achieving homogeneous dispersion and enhanced properties in polymer matrices.

Purpose of the Study:

• To synthesize and characterize t-hexyldimethylsilylated cellulose (TDMS-Cell) for improved compatibility with PBAT.
• To investigate the effects of TDMS-Cell on the crystallization behavior, mechanical properties, and surface hydrophobicity of PBAT composites.
• To establish structure-property relationships for silanized cellulose/PBAT composites.

Main Methods:

• Homogeneous silanization of microcrystalline cellulose (MCC) using t-hexyldimethylchlorosilane (TDMS-Cl).
• Preparation of TDMS-Cell/PBAT composite films via solution blending and casting in tetrahydrofuran (THF).
• Characterization using structural analysis, thermal analysis (DSC), and mechanical testing (tensile strength, elongation at break).

Main Results:

• Successful grafting of TDMS-Cl onto cellulose confirmed, yielding TDMS-Cell with a degree of substitution of ~2.
• TDMS-Cell acted as a nucleating agent, increasing PBAT crystallization temperature, while also suppressing crystal growth due to steric hindrance.
• Optimal TDMS-Cell loading (3-5 wt%) resulted in simultaneous strengthening (31.25% tensile strength increase) and toughening (37.7% elongation at break increase), alongside enhanced surface hydrophobicity.
• Higher filler loading led to phase separation and aggregation, degrading composite properties.

Conclusions:

• Silanization effectively enhances cellulose compatibility with PBAT, enabling simultaneous improvements in mechanical strength and toughness.
• TDMS-Cell influences PBAT crystallization, offering a method for tuning material properties.
• The study provides insights into interfacial design for PBAT/biomass composites, highlighting potential for applications in flexible packaging and coatings.