Bingbing Pan,
Zihua Liu,
Yiyi Zhang,
Wen Li,
Hui Li,
- Graduate Student, School of Material Science and Engineering, LanZhou University of Technology, LanZhou, China
- Undergraduate Student, School of Material Science and Engineering, LanZhou University of Technology, LanZhou, China
- Graduate Student, School of Material Science and Engineering, LanZhou University of Technology, LanZhou, China
- Graduate Student, School of Material Science and Engineering, LanZhou University of Technology, LanZhou, China
- Professor, School of Material Science and Engineering, LanZhou University of Technology, LanZhou, China
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: Gradient polymer materials; photoinitiated radical polymerization; crosslinked network structure; competitive mechanism; mesoscale simulation
[This article belongs to Journal of Polymer & Composites ]
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Journal of Polymer & Composites
| Volume | 14 | |
| Issue | 04 | |
| Received | 18/06/2026 | |
| Accepted | 22/06/2026 | |
| Published | 02/07/2026 | |
| Publication Time | 14 Days |