Semi-automated quantification of the microstructure of PLA/clay nanocomposites to improve the prediction of the elastic modulus

Poly (lactic acid) (PLA) is one the most promising bio-based and biodegradable polymer. However, its properties limit the range of applications it reaches. The neat PLA can be modified with additives that will alter its final properties. In this work the mechanical properties of PLA and PLA/clay (Cloisite 20A and Cloisite 30B) nanocomposites are studied, as a function of the composition of the nanocomposites and a wide range of processing conditions. The novelty of this work is the development of a methodology using TEM-AIA techniques to statistically representatively quantify the microstructure. The length and the thickness of the clay particles, their distribution and the misalignment are quantified and introduced into micromechanical models in order predict the elastic modulus of the nanocomposites. The study proves that by including the effective clay particle and the misalignment degree (parameters calculated from the TEM-AIA analysis) into the models the predictions improve.