Polímeros: Ciência e Tecnologia
https://revistapolimeros.org.br/article/doi/10.1590/0104-1428.2001
Polímeros: Ciência e Tecnologia
Scientific & Technical Article

Obtenção de amidos termoplásticos para a extrusão de pós cerâmicos

Obtaining thermoplastic starches for extrusion of ceramic powders

Amaral, Laricy Janaína Dias do; Dias, Fernanda Trindade Gonzalez; Zorzi, Janete Eunice; Cruz, Robinson Carlos Dudley

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Resumo

Polímeros termoplásticos podem ser utilizados como veículo orgânico (VO) em processos de conformação de peças cerâmicas por extrusão. Neste contexto, termoplásticos à base de amido surgem como uma alternativa sustentável ao emprego das poliolefinas convencionalmente utilizadas na formulação de pastas cerâmicas. O passo inicial para o desenvolvimento de um feedstock (carga extrudável) é a seleção adequada do sistema polimérico ligante, o qual é responsável por conferir propriedades reológicas adequadas durante o processamento. O presente trabalho se propôs a caracterizar termoplásticos a base de amido obtidos na presença de ácido cítrico e avaliar o potencial de utilização destes materiais na extrusão de pós cerâmicos. A processabilidade das pré-misturas de amido foi avaliada em extrusora dupla-rosca e em reômetro de torque. A variação dos teores de água e glicerol na composição das pré-misturas de amido influenciou significativamente as interações entre as cadeias poliméricas, promovendo alterações nos valores de densidade e de viscosidade para a maior parte das amostras analisadas. O amido foi parcialmente esterificado como efeito da ação do ácido cítrico no sistema. Dentre as formulações investigadas, a amostra hidratada e processada com 34% p/p de glicerol (H-34) foi a que apresentou as melhores propriedades de pasta, podendo ser futuramente empregada em processos de conformação de pós cerâmicos.

Palavras-chave

amido termoplástico, ácido cítrico, extrusão, veículo organico, pós cerâmicos

Abstract

Thermoplastic polymers can be used as organic vehicle (OV) in ceramic parts forming by extrusion. In this context, starch-based thermoplastics arise as a sustainable alternative to polyolefins conventionally used in ceramic slurry formulation. The initial step for the development of a feedstock (extrudable load) is the selection of the polymeric binder system, which is responsible for providing appropriate rheological properties during processing. Accordingly, in this work thermoplastic starches obtained in the presence of citric acid are characterized and evaluated as for the potential use in the extrusion of ceramic powders. The processability of the premixed starches was investigated in a twin-screw extruder and in a mixer torque rheometer. The variation of water and glycerol contents in the composition of the premixed starches significantly influenced the interactions between polymer chains, promoting changes in density and viscosity for most analysed samples. The thermoplastic starches were partly esterified as an effect of the citric acid presence in the system. Among all formulations investigated, the H-34 sample (hydrated and processed with 34% w/w of glycerol content) showed the best paste properties and can be further employed in ceramic powder forming processes.

Keywords

thermoplastic starch, citric acid, extrusion, organic vehicle, ceramic powders

References

1. Lörcks, J. (1998). Properties and applications of compostable starch-based plastic material. Polymer Degradation & Stability, 59(1-3), 245-249. http://dx.doi.org/10.1016/S0141-3910(97)00168-7.

2. Carvalho, A. J. F. (2008). Starch: sources, properties and applications. In: M. N. Belgacem, & A. Gandini. Monomers, polymers and composites from renewable resources (pp. 321-342). Oxford: Elsevier.

3. Buléon, A., Colonna, P., Planchot, V., & Ball, S. (1998). Starch granules: structure and biosynthesis. International Journal of Biological Macromolecules, 23(2), 85-112. http://dx.doi.org/10.1016/S0141-8130(98)00040-3. PMid:9730163.

4. Keetels, C. J. A. M., Oostergetel, G. T., & Van Vliet, T. (1996). Recrystallization of amylopectin in concentrated starch gels. Carbohydrate Research, 30(1), 61-64. http://dx.doi.org/10.1016/S0144-8617(96)00057-4.

5. Corradini, E., Lotti, C., Medeiros, E. S., Carvalho, A. J. F., Curvelo, A. A. S., & Mattoso, L. H. C. (2005). Estudo comparativo de amidos termoplásticos derivados do milho com diferentes teores de amilose. Polímeros: Ciência e Tecnologia, 15, 268-273. http://dx.doi.org/10.1007/s00396-008-1887-x.

6. Averous, L., Fringant, C., Moro, L. (2001). Starch-based biodegradable materials suitable for thermoforming packaging. Starch, 53 (8), 368-371. http://dx.doi.org/0038-9056/2001/0808-0368.

7. Liu, H., Xie, F., Yu, L., Chen, L., & Li, L. (2009). Thermal processing of starch-based polymers. Progress in Polymer Science, 34(12), 1348-1368. http://dx.doi.org/10.1016/j.progpolymsci.2009.07.001.

8. Aichholzer, W., Fritz, H. (1998). Rheological characterization of thermoplastic starch materials. Starch/Stärke, 50, 77-83. http://dx.doi.org/0038-9056/98/0203-0077

9. Reddy, N., & Yang, Y. (2010). Citric acid cross-linking of starch films. Food Chemistry, 118(3), 702-711. http://dx.doi.org/10.1016/j.foodchem.2009.05.050.

10. Redl, A., Guilbert, S., & Morel, M. H. (2003). Heat and shear mediated polymerisation of plasticized wheat gluten protein upon mixing. Journal of Cereal Science, 38(1), 105-114. http://dx.doi.org/10.1016/S0733-5210(03)00003-1.

11. Bretas, R. E. S., & D’Avila, M. A. (2005). Reologia de polímeros fundidos (2. ed.). São Carlos: EduFSCAR.

12. Karapantsios, T. D., Sakonidou, E. P., & Raphaelides, S. N. (2002). Water dispersion kinetics during starch gelatinization. Carbohydrate Polymers, 49(4), 479-490. http://dx.doi.org/10.1016/S0144-8617(02)00005-X.

13. Akdogan, H. (1996). Pressure, torque, and energy responses of a twin screw extruder at high moisture contents. Food Research International, 29(5-6), 423-429. http://dx.doi.org/10.1016/S0963-9969(96)00036-1.

14. Thiré, R. S. M. S., Simão, R. A., & Andrade, C. T. (2003). High resolution imaging of the microstructure of maize starch films. Carbohydrate Polymers, 54(2), 149-158. http://dx.doi.org/10.1016/S0144-8617(03)00167-X.

15. Marquez, A., Quijano, J., & Gaulin, M. (1996). A Calibration Technique to Evaluate the Power Law Parameters of Polymer Melts Using a Torque Rheometer. Polymer Engineering and Science, 36(20), 2556-2563. http://dx.doi.org/10.1002/pen.10655.

16. Byrne, R. (1984). What is a torque rheometer? In: R. Byrne. Technical bulletin (pp. 1-6). New Jersey: HaakeBuchler Instruments Inc.

17. Thygesen, L. G., Løkke, M. M., Micklander, E., & Engelsen, S. B. (2003). Vibrational microspectroscopy of food. Raman vs. FT-IR. Trends in Food Science & Technology, 14(1-2), 50-57. http://dx.doi.org/10.1016/S0924-2244(02)00243-1.

18. Wang, J., Yu, L., Xie, F., Chen, L., Li, X., & Liu, H. (2010). Rheological properties and phase transition of corn starches with different amylose/ amylopectin ratios under shear stress. Stärke, 62(12), 667-675. http://dx.doi.org/10.1002/star.201000059.

19. Oliveira, C. F. P., Valera, T. S., & Dermaquette, N. R. (2013). Comparando a utilização de diferentes ácidos carboxílicos nos amidos termoplásticos. In: Anais do 12º Congresso Brasileiro de Polímeros (pp. 1-4). Florianópolis: Santa Catarina.

20. Dogan, H., Karwe, M. V. (2003). Physicochemical properties of quinoa extrudates. Food Science and Technology International, 9(2), 101-114. http://dx.doi.org/10.1177/108201303033940.

21. Kokini, J. L. (1993). The effect of processing history on chemical changes in single and twin screw extruders. Trends in Food Science, 4(10), 324-329. http://dx.doi.org/10.1016/0924-2244(93)90102-G.

22. Ismael, M. R., Clemens, F., Graule, T., & Hoffmann, M. J. (2011). Effects of different thermoplastic binders on the processability of feedstocks for ceramic co-extrusion process. Ceramics International, 37(8), 3173-3182. http://dx.doi.org/10.1016/j.ceramint.2011.05.084.

23. Heiber, J., Clemens, F., Graule, T., & Hülsenberg, D. (2005). Thermoplastic extrusion to highly-loaded thin green fibres containing Pb(Zr,Ti)O3. Advanced Engineering Materials, 7(5), 404-408. http://dx.doi.org/10.1002/adem.200500052.

24. Fang, J. M., Fowler, P. A., Sayers, C., & Willians, P. A. (2004). Chemical modification of a range of starches under aqueous reaction condition. Carbohydrate Polymers, 55(3), 283-289. http://dx.doi.org/10.1016/j.carbpol.2003.10.003.

25. Muscat, D., Adhikari, B., Adhikari, R., & Chaudhary, D. S. (2012). Comparative study of film forming behaviour of low and high amylose starches using glycerol and xylitol plasticizers. Journal of Food Engineering, 109(2), 189-201. http://dx.doi.org/10.1016/j.jfoodeng.2011.10.019.

26. Heliodoro, V. F. M. (2013). Estudo das propriedades físico-químicas de filmes de amido e blendas amido/látex: propriedades térmicas e de transporte de vapor de água (Dissertação de mestrado). Universidade Federal de Uberlândia, Uberlândia.

27. Carvalho, A. J. F., Zambon, M. D., Curvelo, A. A. S., & Gandini, A. (2005). Thermoplastic starch modification during melting processing: hydrolysis catalyzed by carboxylic acids. Carbohydrate Polymers, 62(4), 387-390. http://dx.doi.org/10.1016/j.carbpol.2005.08.025.

28. Shi, R., Zhang, Z., Liu, Q., Han, Y., Zhang, L., Chen, D., & Tian, W. (2007). Characterization of citric acid/glycerol co-plasticized thermoplastic starch prepared by melt blending. Carbohydrate Polymers, 69(4), 748-755. http://dx.doi.org/10.1016/j.carbpol.2007.02.010.

29. Miranda, V. R., & Carvalho, A. J. F. (2011). Blendas compatíveis de amido termoplástico e polietileno de baixa densidade compatibilizadas com ácido cítrico. Polímeros, 21(5), 353-360. http://dx.doi.org/10.1590/S0104-14282011005000067.

30. Jiugao, Y., Ning, W., & Xiaofei, M. (2005). The effects of citric acid on the properties of thermoplastic starch plasticized by glycerol. Stärke, 57(10), 494-504. http://dx.doi.org/10.1002/star.200500423.

31. Tester, R. F., Karkalas, J., & Qi, X. (2004). Starch-composition, fine and architecture. Journal of Cereal Science, 39(2), 151-165. http://dx.doi.org/10.1016/j.jcs.2003.12.001.

32. Lin, C., & Tung, C. (2009). The preparation of glycerol pseudo-thermoplastic starch (GTPS) via gelatinization and plasticization. Polymer-Plastics Technology and Engineering, 48(5), 509-515. http://dx.doi.org/10.1080/03602550902824309.

33. Rodriguez-Gonzalez, F. J., Ramsay, B. A., & Favis, B. D. (2004). Rheological and thermal properties of thermoplastic starch with high glycerol content. Carbohydrate Polymers, 58(2), 139-147. http://dx.doi.org/10.1016/j.carbpol.2004.06.002.

34. Zavareze, E. R., & Dias, A. R. G. (2011). Impact of heat-moisture treatment and annealing in starches: a review. Carbohydrate Polymers, 83(2), 317-328. http://dx.doi.org/10.1016/j.carbpol.2010.08.064.

35. Gomes, A. M. M., Silva, C. E. M., Ricardo, N. M. P. S., Sasaki, J. M., & Germani, R. (2004). Impact of annealing on the physicochemical properties of unfermented cassava starch. Stärke, 56(9), 419-423. http://dx.doi.org/10.1002/star.200300271.
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