Role of Entanglement in Polymer Crystal Growth and Melting: Molecular Dynamics Simulations

• DOI: 10.1021/acs.macromol.4c01877
• Publication Date: 2024-10-31T20:51:19Z
• Authors: Fan Peng; Renkuan Cao; Hao Sun; Ziwei Liu; Yunhan Zhang; Tingyu Xu; Liangbin Li
• Keywords: Dynamics; Crystal (programming language)

The influence of entanglement on the growth and melting polymer crystals is investigated by using molecular dynamics simulations across systems with different densities. Reducing density leads to a slight decrease crystal thickness L but an increase temperature Tm. To elucidate entanglement-related inverse relation between Tm L, we introduce fold surface free energy σf predominantly governed conformational entropy loss amorphous segments. results in σf. Combining contributions linear σf/L obtained, which consistent prediction Gibbs–Thompson equation. Crystallization commonly accompanies disentanglement, while precedes before reconstruction. Considering thermodynamic contribution entanglement, crystallization are not two mutually reversible phase transitions, only kinetically also thermodynamically.