This experiment blends PLLA and PDLA across different molecular-weight combinations at a fixed 50:50 ratio with 10 wt% epoxidized soybean oil. It quantifies links among stereocomplex crystallization, thermal stability, and mechanical behavior and validates a finite-element tensile model.
Key findings
- Reducing both molecular weights raised stereocomplex selectivity from 0.46 to 0.96 and crystallinity to 47%, with initial decomposition temperatures improving by up to 25.6°C. The approximately 47% crystalline samples were too brittle for tensile testing, whereas L130D120 at 13.68% crystallinity reached 36.4% elongation. FEA reproduced tested tensile behavior within 5% error.
Why this matters globally
The quantitative relationships can guide bio-based PLA formulations balancing heat resistance, stiffness, and ductility for packaging or engineering parts. Modeling may reduce experimental iterations, but manufacturing, aging, and end-of-life performance remain important.
Thai researcher contribution
Mahasarakham University researchers contributed through an international collaboration linking Thai manufacturing and materials expertise with polymer experiments and finite-element modeling.
Limitations to consider
The blend ratio and plasticizer content were fixed, limiting separation of ESO and composition effects. Highly crystalline samples could not be tensile-tested, and within-dataset FEA agreement does not establish out-of-domain prediction. Aging, hydrolysis, processing window, biodegradation, and cost were not reported.
Verify the original sources
Polymer Engineering and ScienceRead the original article↗DOI: 10.1002/pen.70714