STM Journals Peer-reviewed research from Consortium e-Learning Network

Journal of Polymer & Composites Original Research

Dissipative Particle Dynamics Simulation Study on the Evolution of Photoinitiated Free Radical Polymerization Crosslinked Networks

  1. Bingbing Pan School of Material Science and Engineering, LanZhou University of Technology
  2. Zihua Liu School of Material Science and Engineering, LanZhou University of Technology
  3. Yiyi Zhang School of Material Science and Engineering, LanZhou University of Technology
  4. Wen Li School of Material Science and Engineering, LanZhou University of Technology
  5. Hui Li School of Material Science and Engineering, LanZhou University of Technology

Abstract

Gradient polymer materials overcome the limitations of conventional homogeneous polymers by integrating multiple distinct functionalities within a single continuous structure. Although photoinitiated free-radical polymerization offers excellent spatial and temporal control, the underlying microscopic mechanisms governing network evolution under non-uniform light fields remain poorly understood. In this study, a mesoscale dissipative particle dynamics (DPD) model was successfully developed to couple free-radical polymerization kinetics—including initiation, propagation, crosslinking, and termination—with exponential light attenuation along the z-axis via the Lambert–Beer law, characterized by a dimensionless parameter k. The simulation results systematically demonstrate that light attenuation acts as the fundamental driver of gradient structure formation by restricting local radical generation. Increasing k confines radical initiation primarily to the near-light region, thereby inducing a pronounced spatial asynchrony in monomer consumption and chain propagation. This severe kinetic heterogeneity yields a distinct topological gradient under strong attenuation: the near-light region forms a dense network characterized by short-chain, highly crosslinked domains, whereas the far-light region features longer chains and a loose morphology. Notably, strong light attenuation creates an environment where localized growing chains compete intensely for crosslinkers, significantly enhancing crosslinking site utilization efficiency. These molecular-level insights provide crucial theoretical guidance and a predictive framework for the rational design and controllable fabrication of advanced gradient polymer materials.

Keywords

References (51)

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