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Ultrastrong, Free-Standing and Large Nanofilms of Pyrenearamid
preprintsubmitted on 24.05.2019, 14:19 and posted on 28.05.2019, 15:10 by Amalia Rapakousiou, Alejandro López-moreno, Belén Nieto-Ortega, M. Mar Bernal, Miguel A. Monclús, Santiago Casado, Cristina Navío, Luisa R. González, Juan P. Fernández-Blázquez, Juan J. Vilatela, Emilio Pérez
We introduce poly(1,6-pyrene terephthalamide) polymer (PPyrTA) as an aromatic polyamide analogue of poly(p-phenylene terephthalamide) (PPTA), also known as Kevlar®. This work shows that the incorporation of polycyclic aromatic pyrene moieties improves drastically the mechanical properties of the polymeric structure, increasing elastic nanoindentation-determined modulus and hardness by factors of 1.9 and 4.3, respectively. Liquid deprotonated dispersions of PPyrTA nanofibers were used as nanoscale building block for producing large-surface, free-standing polymer macroscopic nanofilms. This 2D assembly leads to further significant improvements in reduced modulus and hardness (more than twice) compared to the starting polymer macroscale fibres, due to a better re-organizational arrangement of the PPyrTA nanofibers in the nanofilms, formed under 2D spatial confinement.