Property Measurement and Processing Parameter Optimization for Polylactide Micro Structure Fabrication by Thermal Imprint

Abstract

Polylactide (PLA) is a thermoplastic polymer derived from renewable resources. In this study, we measured the material properties and forming conditions of PLA under the thermal imprint process. The properties of PLA were investigated under various imprint temperatures and imprint times. The results show that increasing the imprint temperature and imprint time results in a progressive rise in Young's modulus and a decrease in elongation at break. Furthermore, if the imprint time exceeds 10 min, crystallinity at imprint temperatures 90 and 110 °C increases visibly. Measurements of rheology properties was performed and the results show viscoelastic behaviors which are combination of irreversible viscous flow and reversible elastic deformation at the temperature of 110–180 °C. The forming conditions of PLA micro structures under thermal imprint technology were studied based on the Taguchi method. The experimental results show that the transfer rate was enhanced to 96.3%. This study therefore contributes to research on the fabrication of biomedical devices using biodegradable polymers produced by the thermal imprint process.

Theoretical and experimental study of a circular imprint process for fabricating polylactide stents

“…A previous study showed that crystallinity may have major effects on PLA's mechanical properties, especially hardness, Young's modulus, and elongation at break in the thermal imprint process. 31) From this study, hardness, Young's modulus, and elongation at break in the thermal imprint process from 60 to 180 s were affected slightly by crystallinity, and we can summarize that an imprint time of 60 s or below was suitable for circular imprint in this study. These results were used for the compressibility simulation of the PLA stent.…”