Comportamento da biodegradação de amostras de PLA natural e pigmentado obtidas por impressão 3D
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Tipo de produção
Dissertação
Data
2021
Autores
Gonzaga, Graziela Lisboa
Orientador
Souza, Adriana Martinelli Catelli de
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Citação
GONZAGA, Graziela Lisboa. Comportamento da biodegradação de amostras de PLA natural e pigmentado obtidas por impressão 3D. São Bernardo do Campo, 2021. 83 p. Dissertação (Mestrado em Mecânica) - Centro Universitário FEI, São Bernardo do Campo, 2021. Disponível em: https://doi.org/10.31414/EM.2021.D.131348.
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Palavras-chave
biodegradação,polímeros,impressão 3D
Resumo
A impressão tridimensional (3D) vem ganhando destaque por conta do aumento da sua
aplicação na produção de peças de artesanato, implantes, próteses e outros. Dentre os métodos
de impressão 3D, o Fused Method Deposition (FDM) possui melhor custo-benefício e utiliza
polímeros como matéria prima. O Poli (ácido láctico) (PLA) é um dos polímeros que vem sendo
muito empregado nesta técnica, principalmente devido as suas boas propriedades mecânicas,
por poder ser obtido por fontes renováveis e ser biocompatível, biorreabsorvível e
biodegradável. O presente trabalho teve como objetivo o estudo do comportamento da
biodegradação de amostras de PLA, natural e pigmentado, obtidas por meio de impressão 3D.
A biodegradação foi avaliada em três temperaturas diferentes: 21°C, 28°C e 35°C pela técnica
de respirometria e análise estatística de variância (ANOVA). Além de analisar a influência da
pigmentação e da temperatura, também foi avaliada a influência do processo de obtenção das
peças, já que também foram confeccionadas peças por prensagem. As amostras antes e após a
biodegradação foram caracterizadas por meio de análises térmicas (DSC e TGA) e FTIR. Foi
observado que, independente da presença de pigmento, a biodegradação é facilitada com o
aumento da temperatura. A análise realizada utilizando-se o método de Arrenhius indicou que
o PLA natural apresentou uma energia de ativação inferior em relação ao PLA pigmentado,
indicando que a pigmentação dificultou ou atrasou a biodegradação do PLA. Observou-se
também que a biodegradação de amostra de PLA natural obtida por impressão 3D foi facilitada
em relação a amostra obtida por prensagem. A análise de DSC mostrou que as amostras de PLA
pigmentado podem ser mais sensíveis ao processo de degradação por hidrólise. No entanto, os
ensaios de evolução de CO2 não corroboram o comportamento observado pois indicaram uma
menor eficiência na biodegradação. Provavelmente, o PLA pigmentado seja mais sensível à
hidrólise, mas o pigmento dificultou o processo de absorção pelos microrganismos. A análise
de TGA mostrou que o decréscimo da temperatura de decomposição foi mais drástico nas
amostras de PLA pigmentado em comparação ao PLA natural, o que corrobora com a análise
de DSC. Por fim, não foram observadas mudanças nos espectros de FTIR das amostras
degradadas em comparação com as não degradadas.
3D printing is gaining prominence due to the increase of its application in the production of handicrafts, implants, protheses and others. Among the 3D printing methods, the Fused Method Deposition (FDM) has the best cost-benefit and uses polymers as raw material. Poly (lactic acid) (PLA) is one of the polymers that has been widely used by this technique, mainly due to its good mechanical properties, as it can be obtained from renewable sources and is biocompatible, bio-absorbable and bio-degradable. The present work aimed to study the biodegradation behavior of PLA samples, natural and pigmented, obtained through 3D printing. Biodegradation was evaluated at three different temperatures: 21 ° C, 28 ° C and 35 ° C by the technique of respirometry and statistical analysis of variance (ANOVA). In addition to analyzing the influence of pigmentation and temperature, the influence of the process of obtaining the pieces was also evaluated, since pieces were also made by pressing. Samples before and after biodegradation were characterized by thermal analysis, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) analysis. It was observed that regardless of the presence of pigment, biodegradation is facilitated with an increase in temperature. In the analysis by the Arrenhius method, the natural PLA presented a lower activation energy in relation to the pigmented PLA, indicating that the pigmentation hindered or delayed the biodegradation of the PLA. Regarding the way of obtaining the samples, the biodegradation of the natural PLA sample obtained by 3D printing was facilitated in relation to the sample obtained by pressing. The DSC analysis showed that the pigmented PLA samples may be more sensitive to the process of degradation by hydrolysis. However, the CO2 evolution tests do not corroborate the observed behavior as they indicated a lower efficiency in biodegradation. It is possible that the pigmented PLA is more sensitive to hydrolysis, but the pigment hinders the process of absorption by microorganisms. The TGA analysis showed that the decrease in the decomposition temperature was more drastic in the samples of pigmented PLA compared to natural PLA, which corroborates the DSC analysis. Finally, there were no changes in the FTIR spectra of the degraded samples compared to the non-degraded ones.
3D printing is gaining prominence due to the increase of its application in the production of handicrafts, implants, protheses and others. Among the 3D printing methods, the Fused Method Deposition (FDM) has the best cost-benefit and uses polymers as raw material. Poly (lactic acid) (PLA) is one of the polymers that has been widely used by this technique, mainly due to its good mechanical properties, as it can be obtained from renewable sources and is biocompatible, bio-absorbable and bio-degradable. The present work aimed to study the biodegradation behavior of PLA samples, natural and pigmented, obtained through 3D printing. Biodegradation was evaluated at three different temperatures: 21 ° C, 28 ° C and 35 ° C by the technique of respirometry and statistical analysis of variance (ANOVA). In addition to analyzing the influence of pigmentation and temperature, the influence of the process of obtaining the pieces was also evaluated, since pieces were also made by pressing. Samples before and after biodegradation were characterized by thermal analysis, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) analysis. It was observed that regardless of the presence of pigment, biodegradation is facilitated with an increase in temperature. In the analysis by the Arrenhius method, the natural PLA presented a lower activation energy in relation to the pigmented PLA, indicating that the pigmentation hindered or delayed the biodegradation of the PLA. Regarding the way of obtaining the samples, the biodegradation of the natural PLA sample obtained by 3D printing was facilitated in relation to the sample obtained by pressing. The DSC analysis showed that the pigmented PLA samples may be more sensitive to the process of degradation by hydrolysis. However, the CO2 evolution tests do not corroborate the observed behavior as they indicated a lower efficiency in biodegradation. It is possible that the pigmented PLA is more sensitive to hydrolysis, but the pigment hinders the process of absorption by microorganisms. The TGA analysis showed that the decrease in the decomposition temperature was more drastic in the samples of pigmented PLA compared to natural PLA, which corroborates the DSC analysis. Finally, there were no changes in the FTIR spectra of the degraded samples compared to the non-degraded ones.