Efeito do ácido esteárico em scaffolds de alumina obtidos por manufatura aditiva usando o método de fabricação por filamento fundido

Abstract

Resumo As cerâmicas porosas podem ser utilizadas nas mais diversas aplicações, como na indústria petroquímica e na área da saúde. No entanto, é difícil produzir cerâmicas com formas complexas usando processos convencionais. Neste trabalho, diferentes termoplásticos (PEBD, ABS e PLA) foram utilizados para a extrusão de filamentos com alumina submicrométrica. Estes filamentos foram extrudados com e sem ácido esteárico que, posteriormente, foram utilizados na manufatura aditiva para a impressão de estruturas porosas (scaffolds) pelo método de fabricação por filamento fundido. Foram obtidas imagens por microscopia eletrônica de varredura das amostras com e sem o ácido esteárico, antes e após a sinterização. Estas imagens mostraram que a presença do ácido esteárico reduziu a formação de defeitos, pois além de atuar como dispersante também facilitou a posterior remoção do veículo orgânico do scaffold, antes da sinterização final.

Acrylonitrile‐butadiene‐styrene‐based composites for the manufacture of anthropomorphic simulators

“…The apparent viscosity behavior of the mixtures showed a reduction in viscosity compared to pure ABS concerning shear rate (as shown in Figure 4), similar to the findings of Calafel et al 45 and Smirnov et al 46 This indicates that the mixtures exhibit viscoelastic fluid properties and can be extruded through a finer nozzle under appropriate printing pressure without clogging, meeting the requirements of 3D printing. 47 One contributing factor is the presence of stearic acid or carnauba wax (acting as a surfactant/dispersant), as mentioned by Hnatkova et al 48 and Gorjan et al, 49 and demonstrated in the work of Faccio et al, 26 in which the presence of stearic acid decreased the viscosity, increasing the fluidity of mixtures of ABS with alumina. The percentage increase of surfactant/dispersant from 15 to 25% on the amount of filler in the composites with basic bismuth carbonate was necessary to aid the production of a filament with adequate cylindrical geometry since the increase in the percentage of stearic acid and carnauba wax helps to reduce viscosity.…”

“…An important factor for 3D printing processing is related to the mixture's viscosity, which decreases as the amount of filler in the mix increases 24 . Furthermore, the addition of waxes and carboxylic acids (with the function of surfactants) helps in solving problems of dispersion and agglomeration of the added charge 24–26 …”

“…24 Furthermore, the addition of waxes and carboxylic acids (with the function of surfactants) helps in solving problems of dispersion and agglomeration of the added charge. [24][25][26] Filaments to mimic high-attenuation tissues such as bone, dentin, and enamel still need to be developed to produce accurately 3D-printed phantoms using material extrusion printing technology. 18 Furthermore, the materials applied to these components must have good strength and durability properties, in addition to suitable 3D printing to be used in biomedical applications.…”