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

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