Partial and Complete Wetting in Ultralow Interfacial Tension Multiphase Blends with Polylactide

Area of Science:

• Polymer Science
• Materials Science
• Physical Chemistry

Background:

• Polylactide (PLA) blends offer tunable properties for wider applications.
• Controlling phase morphology is crucial for optimizing blend performance.
• Understanding interfacial phenomena is essential for designing advanced polymer systems.

Purpose of the Study:

• To investigate the phase behavior and wetting phenomena in ternary and quaternary blends of PLA with PBS, PBAT, and PHBV.
• To explore the influence of blend composition on interfacial tension and morphology.
• To correlate experimental observations with spreading theory.

Main Methods:

• Melt blending to prepare ternary and quaternary polymer blends.
• Interfacial tension measurements using three distinct techniques.
• Fourier transform infrared (FTIR) imaging for phase identification.
• Quiescent annealing to study morphological evolution.

Main Results:

• Ternary PLA/PBS/PBAT blends exhibit tricontinuous complete wetting behavior.
• Quaternary blends show concentration-dependent wetting.
• At 10 vol% PBAT, stable, self-assembled PBAT droplets form.
• At 25 vol% PBAT, a quadruple continuous system transforms into partially wet droplets after annealing.

Conclusions:

• Blend composition significantly impacts phase structuring and wetting behavior.
• Spreading theory accurately predicts the observed morphological transitions.
• Precise control over composition allows for complete alteration of spreading behavior in multiphase systems.