Stereocomplex formation in mixed polymers filled with two-dimensional nanofillers

Area of Science:

• Polymer Science
• Materials Science
• Nanotechnology

Background:

• Stereocomplex formation in poly(l-lactide)/poly(d-lactide) blends is crucial for material properties.
• The precise microscopic mechanisms by which nanofillers influence stereocomplex crystallite (SC) formation remain incompletely understood.
• Graphene and other nanofillers are known to promote SC formation, but the underlying reasons require detailed investigation.

Purpose of the Study:

• To elucidate the microscopic mechanism through which two-dimensional nanofillers affect stereocomplex crystallite formation in polylactide blends.
• To investigate the role of nanofiller-polymer interactions and heterogeneous nucleation in SC development.
• To provide a fundamental understanding of nanofiller-induced crystallization in polymer blends.

Main Methods:

• Dynamic Monte Carlo simulations were employed to model the behavior of polymer chains and nanofillers.
• The simulations focused on analyzing the nucleation and crystallization processes in the presence of two-dimensional nanofillers.
• Key factors such as polymer miscibility, interfacial interactions, and chain packing alignment were examined.

Main Results:

• Nanofillers induce heterogeneous nucleation of mixed polymer chains, facilitating SC formation.
• Improved miscibility of polymers in interfacial regions was observed, attributed to attractive polymer-nanofiller interactions.
• Chains demonstrated a preference for intermolecular packing alignment during heterogeneous nucleation, further promoting SC development.

Conclusions:

• The study reveals that nanofillers act as nucleation sites, enhancing stereocomplex crystallite formation in polylactide blends.
• Both improved interfacial miscibility and facilitated intermolecular chain alignment contribute to the observed promotion of SCs.
• The findings offer a microscopic mechanistic explanation for the effectiveness of nanofillers in modifying the crystallization behavior of polymer blends.