Morphological, Thermal, and Mechanical Behavior of Polyamide11/Sepiolite Bio-Nanocomposites Prepared by Melt Compounding and In Situ Polymerization

The use of bio-based plastics as polymeric matrices to produce technical composites has become an important topic in material science. In this sense, bio-based polyamides represent an interesting alternative to their petroleum-based counterparts because of their good thermal and mechanical properties, their low specific weight, and their ability to be used in complex parts by injection molding. In the present study, bio-based polyamide 11/sepiolite nanocomposites were prepared using the two most feasible techniques from the industrial point of view: melt compounding and in situ polymerization. The effect of the preparation approach and the amount of nanoclay were evaluated to check their influence on thermal, morphological, and mechanical behavior of the final nanocomposites. Regardless of the preparation approach, all nanocomposites showed improvements in thermo-mechanical properties with increasing contents of sepiolite. However, the nanocomposites obtained by in situ polymerization presented higher values of Young's modulus, tensile strength, and heat distortion temperature due to a greater dispersion of the nanoclay in the final composites. For in situ polymerization, the dispersion of sepiolite nanoparticles is carried out when polymer chains are growing and the viscosity of the system is low. POLYM. COMPOS., 40:E704-E713, 2019. (c) 2018 Society of Plastics Engineers