SYNTHESIS OF POLYMERIC NANOCOMPOSITES BY INFILTRATION. APPLICATIONS IN 3D (FUSED FILAMENT MOLDING) PRINTING

RIBERI, KEVIN; PEREYRA, JESICA YANINA; BARBERO, CESAR ALFREDO

Cancum

Congreso; XXVII INTERNATIONAL MATERIALS RESEARCH CONGRESS; 2018

The Sociedad Mexicana de Materiales

Polymeric nanocomposites consist of nanomaterials (e.g. nanoparticles) dispersed in polymer matrices. Nanocomposites can be manufactured by polymer processing methods such as mixing/extrusion. However, these methods produce isotropic materials whose properties could not fit the application.The development of plastic parts using 3D printers by FFM (fused filament molding),requires the manufacture of filaments based on nanocomposites. The way of building the piece allows the use of non-isotropic filaments where only the surface exposed is a nanocomposite.In the present work a method of manufacturing filaments based on polymeric nanocomposites that allow controlling the degree and distribution of the nanomaterial is described. Commercial filaments (polyurethane: PU and polylactic acid: PLA) are used as a polymer matrix. The proposed method requires the swelling of the polymer matrix in a mixture of miscible solvents, one of which acts as a good solvent (it is able to dissolve the polymer) and another as a poor solvent (it is unable to dissolve the polymer). Initially, the kinetics of swelling of pieces of the matrix in different mixtures using gravimetry is investigated. Nanomaterials (molybdenum sulfide: S2Mo, nanographite: NG) aredispersed in one of the pure solvents or in the mixture using an ultrasonic cavitator. The stability of the colloidal solution is evaluated using turbidimetry. The immersion of the filaments in the colloidal solution allows the incorporation of the nanomaterial into the polymer matrix. The modified filament is vacuum dried to remove the swelling solvents. Although it was possible to find solvents that swell PLA, the dispersions of S2Mo are not stable in these media.On the contrary, PU can be swelled in solutions of vinylpyrrolidone (VP)/water in which the colloidal solution of S2Mo is stable. In this way, filaments based on S2Mo / PU nanocomposites are manufactured. The distribution in the filament is evaluated by microscopy. Since the S2Mo is a solid lubricant, the coefficient of friction of the plastic parts manufactured using the nanocomposites is investigated. Using the filaments, forms aremanufactured using a 3D printer (FFM).