Orientational cross correlations between entangled branch polymers in primitive chain network simulations.

Area of Science:

• Polymer physics
• Rheology
• Computational materials science

Background:

• Orientational cross-correlation (OCC) between entangled polymers is crucial for understanding relaxation modulus.
• Previous studies have not fully explored OCC contributions in branched polymers.

Purpose of the Study:

• Investigate OCC contributions in 4- and 6-arm star-branched and H-branched polymers.
• Quantify and compare inter-chain and intra-chain OCC in various polymer architectures.

Main Methods:

• Utilized multi-chain slip-link simulations for molecular-level analysis.
• Traced segment orientation for individual molecules and subchains.
• Calculated OCC between different molecules and subchains.

Main Results:

• Inter-chain OCC in branched polymers is comparable to linear polymers.
• Intra-chain OCC is significantly lower than inter-chain OCC.
• Intra-chain OCC intensity and dynamics are influenced by branching architecture and molecular weight.

Conclusions:

• OCC effects are embedded within the stress-optical coefficient, independent of branching.
• Findings support the validity of single-chain models in polymer rheology.
• Highlights the importance of considering both inter- and intra-chain correlations in polymer dynamics.