# Coarse-Grained Simulations of Crystallization in Phase-Separated Polymer Blends with Block Copolymer Compatibilizers

## TL;DR

This paper uses simulations to study how block copolymers affect crystallization in polymer blends, showing that interfaces and compatibilizers reduce crystallinity.

## Contribution

The study introduces a new simulation framework to explore crystallization suppression in polymer blends due to interfacial incompatibility and compatibilizer effects.

## Key findings

- Broad interfaces between polymers hinder crystallization due to incompatible species, not entanglement.
- Block copolymer compatibilizers reduce interfacial crystallinity by impeding disentanglement.
- Long copolymers can form tie bridges but also hinder loop bridge formation by suppressing crystallization.

## Abstract

We employ coarse-grained molecular dynamics simulations
to investigate
crystallization in binary blends of phase-separated semicrystalline
polymers with and without block copolymer compatibilizers. To mimic
realistic semicrystalline polymer blends, we introduce mismatches
in monomer sizes of different polymers to avoid artificial cocrystallization.
By tuning the intermolecular interactions, we adjust the incompatibility
and the width of the interfaces between different polymers. We find
that broad interfaces significantly hinder crystallization and crystal
stem growth, not due to entanglement constraints, but because of the
presence of incompatible species near the interface. The suppression
of crystallization extends beyond the interfacial region. Adding block
copolymer compatibilizers, which impede disentanglement near the interface,
further reduces interfacial crystallinity. While long copolymers can
form tie bridges across interfaces and offer potential mechanical
reinforcement, they also hinder the formation of entangled loop bridges
by reducing crystallization near interfaces.