Molecular weight effects on chain pull-out fracture of reinforced polymeric interfaces

TL;DR

This study uses Brownian dynamics simulations to analyze how the molecular weight of diblock connector chains influences the fracture toughness of reinforced polymer interfaces, revealing different scaling behaviors for short and long chains.

Contribution

It introduces a scaling argument that explains the dependence of fracture toughness on chain length, bridging short and long chain regimes.

Findings

Fracture toughness depends linearly on chain length for short chains.

For longer chains, toughness scales as the chain length to the power of 3/2.

A unified scaling model accounts for both regimes and their crossover.

Abstract

Using Brownian dynamics, we simulate the fracture of polymer interfaces reinforced by diblock connector chains. We find that for short chains the interface fracture toughness depends linearly on the degree of polymerization $N$ of the connector chains, while for longer chains the dependence becomes $N^{3/2}$. Based on the geometry of initial chain configuration, we propose a scaling argument that accounts for both short and long chain limits and crossover between them.