Preparation of oriented poly(lactic acid) thin films by a combination of high temperature rubbing and thermal annealing: Impact of annealing parameters on structure, polymorphism and morphology

Marion Brosset (1, 2) , Laurent Herrmann (1) , Thierry Falher (2) , Martin Brinkmann (1)

1 ICS - Institut Charles Sadron
2 centre technique de la plasturgie et des composites

High temperature rubbing is a fast and low-cost method to prepare highly oriented films of polymers. This contribution describes the fabrication of smooth and pin-hole-free poly(lactic acid) (PLA) thin films of controlled structure and morphology using a combination of rubbing at moderate temperature (T ≤ 100°C) and thermal annealing. We investigate the impact of annealing temperature and duration on the structure of rubbed PLLA and stereo-complex (SC) thin films. The importance of annealing parameters on polymorphism, crystallinity, crystal dimensions and in-plane orientation are analyzed using Transmission Electron Microscopy, Differential Scanning Calorimetry and FTIR spectroscopy. Regarding SC PLA films, the conditions are identified to fully transform the equimolar PLLA-PDLA blend films into pure oriented SC films without presence of homocrystals.

Domaines: Matériaux

Marion Brosset, Laurent Herrmann, Thierry Falher, Martin Brinkmann. Preparation of oriented poly(lactic acid) thin films by a combination of high temperature rubbing and thermal annealing: Impact of annealing parameters on structure, polymorphism and morphology. Journal of Polymer Science, 2023, ⟨10.1002/pol.20220740⟩. ⟨cea-03956730v1⟩