Sains Malaysiana 40(7)(2011): 713–718

 

Tensile and Water Absorption Properties of Biodegradable Composites Derived from Cassava Skin/Polyvinyl Alcohol with Glycerol as Plasticizer

(Sifat-sifat Tegangan dan Penyerapan Air oleh Komposit Biorosot daripada Kulit Ubi Kayu/Polivinil Alkohol dengan Gliserol sebagai Bahan Pemplastik)

 

Dayangku Intan Munthoub* & Wan Aizan Wan Abdul Rahman

Department of Polymer Engineering, Faculty of Chemical Engineering and Natural Resources

Universiti Teknologi Malaysia, 81310 Skudai, Johor D.T., Malaysia

 

Diserahkan: 23 Oktober 2009 / Diterima: 25 Oktober 2010

 

 

ABSTRACT

 

Natural organic and abundant resources biopolymers received more attention due to their low cost, availability and degradability after usage. Cassava skin was used as natural fillers to the polyvinyl alcohol (PVA). Cassava skin/poly vinyl alcohol blends were compounded using melt extrusion twin screw extruder and test samples were prepared using the compression method. Various ratios of cassava skin and glycerol were investigated to identify suitable composition based on the water absorption and tensile properties. The water absorption of the cassava skins/PVA samples increased at higher composition of cassava skin due to their hydrophilic properties but decrease with glycerol content. The strength of the cassava skins/PVA samples increased with the higher composition of cassava skin up to 70 wt% while gradually decreased with the increasing composition of glycerol. The Young modulus increased with glycerol content but decreased with fibre loading up to 70 wt%. Elongation at break decreased with fibre loading and glycerol up to 70 wt% and 30 phr, respectively.

 

Keywords: Biodegradable; cassava skin; polyvinyl alcohol; tensile properties; water absorption

 

 

ABSTRAK

 

Bahan organik semula jadi dan sumber biopolimer lebih mendapat perhatian disebabkan oleh kos yang rendah, mudah diperoleh dan mudah terurai. Kulit ubi kayu digunakan sebagai pengisi semula jadi kepada polivinil alkohol (PVA). Adunan kulit ubi kayu/PVA diadun menggunakan kaedah penyemperitan skru berkembar dan sampel disediakan melalui kaedah pemampatan. Gliserol ditambah sebagai bahan pemplastik untuk pemplastikan PVA dan menggalakkan kebolehgerakan adunan. Penyerapan air oleh adunan kulit ubi kayu/PVA meningkat apabila komposisi kulit ubi kayu yang tinggi digunakan disebabkan sifat hidrofilik bahan tersebut tetapi menurun dengan pertambahan gliserol. Kekuatan adunan kulit ubi kayu/PVA meningkat dengan pertambahan komposisi ubi kayu sehingga 70 wt% tetapi menurun dengan pertambahan komposisi gliserol. Modulus Young meningkat dengan pertambahan kandungan gliserol di dalam adunan tetapi menurun apabila kandungan kulit ubi kayu sehingga 70 wt%. Pemanjangan pada takat putus berkurangan dengan pertambahan kulit ubi kayu sehingga 70 wt% dan 30 phr gliserol.

 

Kata kunci: Alkohol polivinil; biourai; kulit ubi kayu; penyerapan air; sifat-sifat tegangan

 

RUJUKAN

 

Alexy, P., Lacík, I., Šimkovic, B., Bakoš, D., Prónayová, N., Liptaj, T., Hanzelová, S. & Várošová, M. 2004. Effect of melt processing on thermo-mechanical degradation of poly(vinyl alcohol)s. Polymer Degradation and Stability 85: 823-830.

Bhatnagar, S. & Hanna, M.A. 1995. Properties of extruded starch-based plastic foam. Industrial Crops and Products 4: 71-77.

Buzarovska, A., Bogoeva-Gaceva, G., Grozdanov, A., Avella, M., Gentile, G. & Errico, M. 2008. Potential use of rice straw as filler in eco-composite materials. Australian Journal of Crop Science 1(2): 37-42.

Carraher, C.E. 2008. Polymer Chemistry. (7th ed). Boca Raton, FL: Taylor & Francis Group. pp 272-273.

Cha, J.Y., Chung, D.S., Seib, P. A., Flores, R.A. & Hanna, M.A. 2001. Physical properties of starch-based foams as affected by extrusion temperature and moisture content. Industrial Crops and Products 14: 23-30.

Chandra, R. & Rustgi, R. 1998. Biodegradable polymers. Progress in Polymer Science 23: 1273-1335.

Chiellini, E., Corti, A.D., Antone, S. & Solaro, R. 2003. Biodegradation of poly(vinyl alcohol) based materials. Progress in Polymer Science 28: 963-1014.

Ganjyal, G.M., Reddy, N., Yang, Y.Q. & Hanna, M.A. 2003. Biodegradable packaging foams of starch acetate blended with corn stalk fibres. Journal of Applied Polymer Science 93: 2627-2633.

Glenn, G.M. & Orts, W.J. 2001. Properties of starch-based foam formed by compression/explosion processing. Industrial crops and Products 13: 135-143.

Glenn, G.M., Orts, W.J. & Nobes, G.A.R. 2001. In situ Laminating process for baked starch-based foams. Industrial Crops and Products. 14: 201-212.

Herald, T.J., Obuz, E., Twombly, W.W. & Rausch, K.D. 2002. Tensile Properties of Extruded Corn Protein Low-Density Polyethylene Films. Cereal Chem. 79(2): 261-264.

Jang, J. & Lee, D.K. 2003. Plasticizer effect on the melting and crystallization behavior of polyvinyl alcohol. Polymer 44: 8139-8146.

Lin, C.A. & Ku, T.H. 2008. Shear and elongation flow properties of thermoplastic polyvinyl alcohol melts with different plasticizer contents and degrees of polymerization. Journal of Materials Processing Technology 200: 331-338.

Lui, W.B. & Peng, J. 2005a. Physical mechanical biodegradable properties and energy absorption behavior of corn grit-polyvinyl alcohol cushioning extrudates. Journal of Food Engineering 71: 73-84.

Lui, W.B. & Peng, J. 2005b. Effects of operating conditions on degradable cushioning extrudates cellular structure and the specific heat. Journal of Food Engineering 70: 171-182.

Nabar, Y., Narayan, R. & Schindler, M. 2006. Twin-screw extrusion production and characterization of starch foam products for use in cushioning and insulation applications. Polymer Engineering and Science 46: 438-451.

Preechawong, D., Peesan, M., Supaphol, P. & Rujiravanit, R. 2004. Characterization of starch poly(ε-caprolactone) hybrid foams. Polymer Testing 23: 651-657.

Preechawong, D., Peesan, M., Supaphol, P. & Rujiravanit, R. 2005. Preparation and characterization of starchpoly(L-lactic acid) hybrid foams. Carbohydrate Polymers 59: 329-337.

Salgado, P.R., Schmidt, V.C., Ortiz, S.E.M., Mauri, A.N. & Laurindo, J.B. 2008. Biodegradable foams based on cassava starch, sunflower proteins and cellulose fibres obtained by a baking process. Journal of Food Engineering 85: 435-443.

Shogren, R.L., Lawton, J.W., Tiefenbacher, K.F. & Chen, L. 1998. Starch-poly(vinyl alcohol) foamed articles prepared by a baking process. Journal of Applied Polymer Sciences 68: 2129-2140.

Torres, F.G., Arroyo, O.H. & Gómez, C. 2007. Processing and mechanical properties of natural fibre reinforced thermoplastic starch biocomposites. Journal of Thermoplastic Composite Materials 20: 207-223.

Tsivintzelis, I., Pavlidou, E. & Panayiotou, C. 2007. Biodegradable polymer foams prepared with supercritical CO2-ethanol mixtures as blowing agents. The Journal of Supercritical Fluids 42: 265-272.

Willett, J.L. & Shogren, R.L. 2002. and properties of extruded starch/polymer foams. Polymer 43: 5935-5947.

Xu, Y.X., Dzenis, Y. & Hanna, M.A. 2005. Water solubility, thermal characteristics and biodegradability of extruded starch acetate foams. Industrial Crops and Products 21: 361-368.

Xu, Y.X. & Hanna, M.A. 2005. Preparation and properties of biodegradable foams from starch acetate and poly(tetramethylene adipate-co-terephthlate). Carbohydrate Polymers 59: 521-529.

Zhou, J., Song, J. & Parker, R. 2006. Structure and properties of starch-based foams prepared by microwave heating from extruded pellets. Carbohydrate Polymers 63: 466-475.

Zhou, J., Song, J. & Parker, R. 2007. Microwave-assisted moulding using expandable extruded pellets from wheat flours and starch. Carbohydrate Polymers 69: 445-454.

 

*Pengarang untuk surat-menyurat; email: dkim_4585@yahoo.com

 

 

 

sebelumnya