Physical and Mechanical Properties of Citric Acid Modified Corn Starch/Microcrystalline Cellulose Films

Abstract

In this study, the effect of citric acid on physical and mechanical properties on glycerol plasticized modified corn starch/microcrystalline cellulose (SC) composite films were investigated. The films were prepared by the casting method. FTIR spectroscopy showed that strong hydrogen bond interactions were formed as a result of the crosslinking of starch and citric acid. Citric acid was added to SC films in different proportions (1%, 5%, 10% and 20%). With the addition of 1% citric acid, the mechanical stress of SC1 exhibited a better tensile strength than SC film without citric acid. In addition, for SC1, the lowest water vapor permeability (WVP) and solubility occurred. While WVP of SC film was 5.56 × 10-7 g Pa-1 s-1 m-1, it was 5.41 × 10-7 g Pa-1 s-1 m-1 with the addition of 1% citric acid, WVP was decreased. Optical properties of the films were also studied. SC films were more opaque than films containing citric acid, moreover, the higher the crosslinker concentration, the lower the opacity.

Keywords

• Çapraz bağlayıcı
• mısır nişastası
• mikrokristalin selüloz

Sitrik Asit ile Modifiye Edilmiş Mısır Nişastası/Mikrokristalin Selüloz Filmlerin Fiziksel ve Mekanik Özellikleri

Abstract

Bu çalışmada gliserol ile plastikleştirilmiş modifiye mısır nişastası/mikrokristalin selüloz (NS) kompozit filmlerin fiziksel ve mekanik özellikleri üzerine sitrik asitin etkisi incelendi. Filmler dökme metoduyla hazırlandı. FTIR spektroskopisinde nişasta ile sitrik asitin çapraz bağlanması sonucu güçlü bir hidrojen bağı oluştuğu görüldü. NS filmlerine farklı oranlarda (%1, %5, %10 ve %20) sitrik asit ilave edildi. %1 oranında sitrik asitin eklenmesiyle NS1 filminin mekanik gerilimi sitrik asit içermeyen NS filmine göre daha iyi bir gerilme kuvveti sergiledi. Ayrıca NS1 filminde en düşük su buharı geçirgenliği (SBG) ve çözünürlük meydana geldi. NS filminin SBG 5.56×10-7 g Pa-1 s-1 m-1 iken, %1 sitrik asit ilavesi ile 5.41×10-7 g Pa-1 s-1 m-1 olup, SBG azalmaktadır. Filmlerin optik özellikleri de incelendi. NS filmleri, sitrik asit içeren filmlere göre daha opaktır, ayrıca çapraz bağlayıcı konsantrasyonu arttıkça opaklık azalmaktadır.

Keywords

• Çapraz bağlayıcı
• mısır nişastası
• mikrokristalin selüloz

References

1. Cheng, J., Zheng, P., Zhao, F., Ma, X., 2013. The composites based on plasticized starch and carbon nanotubes. International Journal of Biological Macromolecules, 59:13-19.
2. Cyras, V. P., Tolosa Zenklusen, M. C., Vazquez, A., 2005. Relationship between structure and properties of modified potato starch biodegradable films. Journal of Applied Polymer Science, 101(6):4313-4319.
3. Galdeano, M. C., Wilhelm, A. E., Mali, S., Grossmann, M. V. E., 2013. Influence of thickness on properties of plasticized oat starch films. Brazilian Archives of Biology and Technology, 56(4):637-644.
4. Ghanbarzadeh, B., Almasi, H., Entezami, A. A., 2011. Improving the barrier and mechanical properties of corn starch-based edible films: Effect of citric acid and carboxymethyl cellulose. Industrial Crops and Products, 33(1):229-235.
5. Gürler, N., Paşa, S., Alma, M. H., Temel, H., 2020. The fabrication of bilayer polylactic acid films from cross-linked starch as eco-friendly biodegradable materials: Synthesis, characterization, mechanical and physical properties. European Polymer Journal, 109588.
6. Jiugao, Y., Ning, W., Xiaofei, M., 2005. The effects of citric acid on the properties of thermoplastic starch plasticized by glycerol. Starch‐Stärke, 57(10):494-504.
7. Khan, B., Niazi, M. B. K., Hussain, A., Jahan, Z., 2017. Influence of carboxylic acids on mechanical properties of thermoplastic starch by spray drying. Fibers and Polymers, 18(1):64-73.
8. Ma, X., Chang, P. R., Yu, J., 2008. Properties of biodegradable thermoplastic pea starch/carboxymethyl cellulose and pea starch/microcrystalline cellulose composites. Carbohydrate Polymers, 72(3):369-375.

9. Ma, X., Chang, P. R., Yu, J., Stumborg, M., 2009. Properties of biodegradable citric acid-modified granular starch/thermoplastic pea starch composites. Carbohydrate Polymers, 75(1):1-8.
10. Menzel, C., Olsson, E., Plivelic, T. S., Andersson, R., Johansson, C., Kuktaite, R., Koch, K., 2013. Molecular structure of citric acid cross-linked starch films. Carbohydrate polymers, 96(1):270-276.
11. Olsson, E., Hedenqvist, M. S., Johansson, C., Järnström, L. 2013. Influence of citric acid and curing on moisture sorption, diffusion and permeability of starch films. Carbohydrate Polymers, 94(2):765-772.
12. Reddy, N., Yang, Y., 2010. Citric acid cross-linking of starch films. Food Chemistry, 118(3):702-711.
13. Sanyang, M. L., Sapuan, S. M., Jawaid, M., Ishak, M. R., Sahari, J., 2016. Development and characterization of sugar palm starch and poly (lactic acid) bilayer films. Carbohydrate Polymers, 146:36-45.
14. Seligra, P. G., Jaramillo, C. M., Famá, L., Goyanes, S. 2016. Biodegradable and non-retrogradable eco-films based on starch–glycerol with citric acid as crosslinking agent. Carbohydrate Polymers, 138:66-74.
15. 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.
16. Zhou, J., Zhang, J., Ma, Y., Tong, J., 2008. Surface photo-crosslinking of corn starch sheets. Carbohydrate Polymers, 74(3):405-410.
17. Zuraida, A., Yusliza, Y., Anuar, H., & Muhaimin, R. M. K., 2012. The effect of water and citric acid on sago starch bio-plastics. International Food Research Journal, 19(2):715.