Preparation and Study on the Properties of LDPE-Thermoplastic Starch Blends; Part II: Water Absorption Behavior

Document Type : Research Note

Authors

1 Chemical Engineering Department, Polymer Group, Isfahan University of Technology, P.O. Box 84156-83111 Isfahan, I.R. IRAN

2 Quality Control Unit, Aryasasol Polymer Company, P.O. Box 75391-369 Asalouyeh, Bushehr, I.R. IRAN

Abstract

In this work, water absorption behaviour of biodegradable low density polyethylene-thermoplastic starch (LDPE-TPS) blends is investigated. Thermoplastic starch was prepared by melt mixing starch and glycerol (35 wt.%) using an internal mixer at 140 °C and rotor speed of 60rpm for 8 minutes. LDPE/TPS blends containing various amounts of starch (10-40 wt.%) were prepared with (3 wt.%) and without PE-g-MA using single screw extruder. Water absorption test was carried out at room temperature and using related standard methods. The results indicate that with increase in TPS content and also increasing the immersion time, water absorption increase unit the constant value is obtained. After 21 days of the immersion time, 10.5% and 16.3% increase in water absorption were obtained for un compatibilized and compatibilized blends containing 40 wt.% TPS, respectively. The results also show that after immersion tests, the tensile properties such as ultimate tensile strength and Young's modulus decrease.

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Main Subjects


[1] Ammala A., Bateman S., Dean K., Petinakis S., Sangwan P., Wong S., Yuan Q., Yu L., An Overview of Degradable and Biodegradable Polyolefins, Prog. Polym. Sci., 36 (8), p.1015 (2011).
[2] هنرکار، ه.، باریکانی، م.، مرشدیان، ج.، تهیه و مطالعه پلی اتیلنی تخریب پذیر برپایه نشاسته، مجله علوم و تکنولوژی پلیمر، (2)18، ص. 107 (1384).
[3] Vieyra Ruiz H., Martínez E.S.M., Méndez M.Á.A., Biodegradability of Polyethylene-Starch Blends Prepared by Extrusion and Molded by Injection: Evaluated by Response Surface Methodology, Starch - Stärke, 63, p. 42 (2011).
[4] Shi B., Shlepr M., Palfery D., Effect of Blend Composition and Structure on Biodegradation of Starch/Ecoflex-Filled Polyethylene Films, J. Appl. Polym. Sci., 120, p.1808 (2011).
[5] Sabetzadeh M., Bagheri R., Masoomi M., Effect of Corn Starch Content in Thermoplastic Starch/Low-Density Polyethylene Blends on Their Mechanical and Flow Properties, J. Appl. Polym. Sci., 126, p.E63 (2012).
[6] Tena-Salcido C., Rodríguez-González F., Méndez-Hernández M., Contreras-Esquivel J., Effect of Morphology on the Biodegradation of Thermoplastic Starch in LDPE/TPS Blends, Polym. Bull, 60, p.677 (2008).
[7] Kahar A.W.M., Ismail H., Othman N., Effects of Polyethylene-Grafted Maleic Anhydride as a Compatibilizer on the Morphology and Tensile Properties of (Thermoplastic Tapioca Starch)/ (High-Density Polyethylene)/(Natural Rubber) Blends, J. Vinyl. Add. Technol, 18, p.65 (2012).
[8] Majid R.A., Ismail H., Taib R.M., Effects of PE-g-MA on Tensile Properties, Morphology and Water Absorption of LDPE/Thermoplastic Sago Starch Blends, Polym. Plast Technol. Eng, 48, p.919 (2009).
[9] Mani R. , Bhattacharya M., Properties of Injection Moulded Starch/Synthetic Polymer Blends--III. Effect of Amylopectin to Amylose Ratio in Starch, Eur. Polym. J, 34, p.1467 (1998).
[10] Cyras V.P., Manfredi L.B., Ton-That M.-T., Vázquez A., Physical, Mechanical Properties of Thermoplastic Starch/Montmorillonite Nanocomposite Films, Carbohyd. Polym., 73, p.55 (2008).
[11] Pérez C.J., Alvarez V.A., Mondragón I., Vázquez A., Water Uptake Behavior of Layered Silicate/Starch-Polycaprolactone Blend Nanocomposites, Polym. Int, 57, p.247 (2008).
[12] Dufresne A., Dupeyre D., Vignon M.R., Cellulose Microfibrils from Potato Tuber Cells: Processing and Characterization of Starch-Cellulose Microfibril Composites, J. Appl. Polym. Sci, 76, p. 2080 (2000).
[13] Danjaji I.D., Nawang R., Ishiaku U.S., Ismail H., Mohd Ishak Z.A.M., Degradation Studies and Moisture Uptake of Sago-Starch-Filled Linear Low-Density Polyethylene Composites, Polym. Test., 21, p.75 (2002).