Poster: Dynamical properties of poly(lactic acid) stereoisomers

Poster presented at 10th International Discussion Meeting on Relaxations in Complex Systems (10thIDMRCS, https://10idmrcs.com/), which was held during July 20-25, 2025 at the Campus Diagonal-Besòs of the Universitat Politècnica de Catalunya-BarcelonaTech. Abstract: We present a computational investigation of the dynamical properties of poly(lactic acid) (PLA) and its stereoisomers, poly(L-lactic acid) (PLLA), poly(D-lactic acid) (PDLA), and copolymers of different composition (PDLLA), using systematic atomistic simulations. PLA, a biocompostable and biocompatible polymer, has garnered significant interest for its sustainable applications; however, its practical utility is often limited by its inherent dynamic characteristics. Understanding the segmental dynamics and glass transition temperature (Tg) of these stereoisomers is crucial for optimizing their processing and performance.Our simulations employed molecular dynamics techniques to explore the local motions within different PLA stereoisomers. We specifically focused on characterizing the segmental dynamics in connection with the local structure, which ultimately influence macroscopic properties such as degree of crystallinity and thus the amorphous or crystalline character of the PLA materials. By analyzing mean square displacements and correlation functions, we elucidated the distinct dynamic behaviors of PLLA, PDLA, and PDLLA. The simulations revealed dissimilar packing at molecular level between the stereoisomers [1], directly impacting their segmental mobility. Furthermore, we estimated the glass transition temperatures for each stereoisomer [2], demonstrating tendencies analogous to experimental observations. The results highlight the profound influence of stereoisomeric configuration on the dynamic properties of PLA, providing valuable insights for the design of novel PLA-based materials with tailored performance characteristics. This study underscores the power of atomistic simulations in unraveling complex polymer dynamics and guiding materials innovation. REFERENCES1. Petra Bačova, Vagelis Harmandaris, and Sergio I. Molina, Macromolecules 2025 58 (16), 8572-8580 https://pubs.acs.org/doi/full/10.1021/acs.macromol.5c009182. Sheintly K. Diaz Gonzalez, Computational study of biodegradable polymers with application in 3D printing, 2025, Master Thesis, University of Cádiz 10.5281/zenodo.17257116