Análise da produção de scaffolds porosos por impressão 3D

Abstract

This work analyzed the feasibility of producing porous scaffolds by 3D printing (3DP) via melt-deposition modeling (FDM) of Poly(lactic acid) (PLA) with azodicarbonamide (AZDN) blowing agent. A selection of the polymer matrix was carried out based on mechanical, rheological and morphological tests, comparing Poly(acrylonitrile-co-butadiene-co-styrene) (ABS), Poly(ethylene terephthalate) bottle grade (PETG) and PLA, both by means of injection molding, as well as by IMP3D, using nozzles with diameters of 0.3; 0.4; 0.5; 0.6; 0.8; 1.0. After weighing the productive efficiency, the processability, and the mechanical results obtained, 3DP and PLA were selected as the most suitable technique and material for the production of porous scaffolds. Subsequently, the PLA was subjected to a closed cycle of five consecutive processes in a twin screw extruder, verifying by the visual and rheological changes, that the material maintained good rheological properties after the thermal cycles. The PLA was mixed with the expanding agent azodicarbonamide (AZDN) in a twin-screw extruder, and plasticized in a singlescrew extruder, obtaining PLA filaments with inert AZDN, for subsequent printing of porous scaffolds, in proportions in percentages per hundred resin of: 100/0; 100/2; 100/4; 100/6; 100/8. The rheological, morphological and uniaxial traction characterizations of the developed materials were carried out, noting the increase in PLA viscosity when subjected to more thermal cycles. The morphologies pointed to a greater emergence of pores for the compositions with higher concentration of AZDN, so that the larger pores were preferentially present in the central regions of the filaments, in addition to showing that the temperature control influences the size of the pores obtained, reaching biodegradable and biocompatible porous structures.