Closely Packed Conductive Droplets with Polygon-Like Patterns Confined at the Interface in Ternary Polymer Blends

Area of Science:

• Polymer Science and Engineering
• Materials Science
• Interface Science

Background:

• Ternary polymer blends offer tunable properties through controlled morphology.
• Understanding interfacial phenomena is crucial for designing advanced polymer systems.
• Conductive polymer phases can impart unique functionalities to insulating matrices.

Purpose of the Study:

• To investigate the morphology development in partially wetted ternary polymer systems.
• To elucidate the mechanism behind the formation of polygon-like droplet patterns.
• To correlate blend composition and processing with interfacial behavior and final microstructure.

Main Methods:

• Melt blending of low-density polyethylene (LDPE), poly(ether-block-amide) (PEBA), and poly(butylene-adipate-co-terephthalate) (PBAT).
• Annealing treatment to induce morphological evolution.
• Microscopy and interfacial tension measurements to analyze droplet formation and coalescence.
• Comparative studies with LDPE/PEBA/polypropylene (PP) and LDPE/PEBA/polystyrene (PS) blends.

Main Results:

• Formation of closely packed conductive poly(ether-block-amide) droplets with polygon-like patterns at a specific blend ratio (50/10/40).
• Transformation of connected conductive phase into dispersed droplets upon annealing, driven by Rayleigh-type instability.
• Slow coalescence rate of poly(ether-block-amide) droplets due to low interfacial tension with poly(butylene-adipate-co-terephthalate).
• Intermediate partial wetting behavior facilitating the unique morphology.

Conclusions:

• The unique morphology is a result of the interplay between slow coalescence, rapid reduction in interfacial area, and intermediate partial wetting.
• Rayleigh-instability drives droplet formation, while low interfacial tension limits their coalescence.
• This study provides insights into controlling morphology in ternary polymer blends for specific applications.