PREPARATION AND CHARACTERIZATION OF THERMOPLASTIC STARCH FROM PINEAPPLE STEM: EFFECT OF PLASTICIZERS
DOI:
https://doi.org/10.55766/sujst-2023-03-e02056Keywords:
Erythritol, Pineapple starch, Plasticizer, Sorbitol, Thermoplastic starch, XylitolAbstract
This work studied the effect of types and amount of plasticizers on thermoplastic starch properties from pineapple stem with good mechanical properties, water resistant and biodegradable. Three plasticizers were studied: erythritol, xylitol, and sorbitol. Thermoplastic starch film was prepared by solution casting. When glycerol was used as co plasticizer, it could improve the flexibility of thermoplastic starch. Thermal properties of thermoplastic starch film by DSC showed that when the plasticizers were added, the heat of fusion (DHm) was reduced. Water absorption of thermoplastic starch films are maximum in 1 hour and constant after immersed in distilled water for 3 hours. Films can maintain in their shapes at least 13 days after that they dissolved. Thermoplastic starch from pineapple stem and plasticizers i.e. sorbitol and xylitol showed no significant difference in water absorption. Thermoplastic starch films from mixed plasticizers showed more hydrophilic when compared with film from single plasticizer. Films without glycerol show high tensile strength and modulus. Thermoplastic starch film from pineapple stem is water resistant and biodegradable in water. All thermoplastic starch degraded within 30 days after biodegradability test in soil. Thermoplastic starch film made from pineapple stem is considered a naturally biodegradable plastic.
References
Baek, M.H., Yoo, B., and Lim, S.T. (2004). Effects of sugars and sugar alcohols on thermal transition and cold stability of corn starch gel. Food Hydrocolloids, 18(1):133-142 https://doi.org/10.1016/S0268-005X(03)00058-4
Huang, M., Yu, J., and Ma, X. (2005). Ethanolamine as a novel plasticiser for thermoplastic starch. Polymer Degradation and Stability, 90:501-507 https://doi.org/10.1016/j.polymdegradstab.2005.04.005
Liu, P., Yu, Long., Liu, H., Chen, L., and Li, L. (2009). Glass transition temperature of starch studied by a high-speed DSC. Carbohydrate Polymers, 77:250-253 https://doi.org/10.1016/j.carbpol.2008.12.027
Mano, J.F., Koniaravo, D., and Reis, R.L. (2003). Thermal properties of thermoplastic starch/synthetic polymer blends with potential biomedical applicability. Journal of Materials Science: Materials in Medicine, 14:127-135 https://doi.org/10.1023/A:1022015712170
Muhammad, B.K. Niazi., Mark, Zijlstra., and Antonius, A.B. (2015). Influence of plasticizer with different functional groups on thermoplastic starch. Journal of Applied Polymer Science. DOI: 10.1002/app.42012
Nakthong, N., Wongsagonsup, R., and Amornsakchai, T. (2017). Characteristics and potential utilizations of starch from pineapple stem waste. Journal of Industrial Crops and Products, 105:74-82 https://doi.org/10.1016/j.indcrop.2017.04.048
Pérez, S., Baldwin P.M., and Gallant, D.J. (2009). Structural Features of Starch Granules I in Starch Chemistry and Technology, (Third Edition), BeMiller J. and Whistler R. Elsevier, UK, p. 149-192. https://doi.org/10.1016/B978-0-12-746275-2.00005-7
Shaw, N.B., Monahan, F.J., Riordan, O., and Sullivan, M.O. (2006). Physical properties of WPI films plasticized with glycerol, xylitol, or sorbitol. Journal of Food Science, 67(1):164-167. https://doi.org/10.1111/j.1365-2621.2002.tb11377.x
