Biodegradable extruded starch blends

We prepared biodegradable extruded starch blends by first mixing starch with additives and then processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, solubility, biodegradability, rheological properties, molecular weight, and glass-transition temperature of the extruded blends were studied. Glycerol and urea, to some extent, could both decrease the tensile strength and increase the percentage elongation at break because the former acts as a plasticizer and the latter can break down interactions among starch macromolecules. The extruded starch blends showed thermoplasticity, and their melts behaved as pseudoplastic liquids at a comparatively low shear rate. The biodegradability of the extruded starch was slightly higher than that of native starch. The molecular weight of starch displayed a decreasing tendency after extruding modification.

[1]  Xiaodong Wang,et al.  Degradation of polyethylene containing ferric salt and starch , 1999 .

[2]  S. Yuan,et al.  Accelerated chemical degradation of polyacrylamide , 1999 .

[3]  Peter A. Williams,et al.  Physico-chemical characterisation of sago starch , 1999 .

[4]  Jiu-gao Yu,et al.  The accelerated degradation of aqueous polyacrylamide at low temperature , 1998 .

[5]  M. Pegoraro,et al.  Positron annihilation study of free volume in cross-linked amorphous polyurethanes through the glass transition temperature , 1998 .

[6]  Jiu-gao Yu,et al.  Graft copolymerization of starch–AN initiated by potassium permanganate , 1998 .

[7]  Jianping Gao,et al.  Preparation of gelatin-N-vinylpyrrolidone graft copolymer , 1998 .

[8]  Jiu-gao Yu,et al.  Comparison of Transition Metals in the Graft Copolymerization of Vinyl Monomers onto Starch , 1998 .

[9]  Jianping Gao,et al.  Graft copolymerization of N-vinylpyrrolidone onto gelatin , 1995 .

[10]  Jiu-gao Yu,et al.  Graft copolymers of methy methacrylate onto canna starch using manganic pyrophosphate as an initiator , 1994 .

[11]  V. Davidson,et al.  A Model for Mechanical Degradation of Wheat Starch in a Single-Screw Extruder , 1984 .

[12]  V. Davidson,et al.  Degradation of Wheat Starch in a Single Screw Extruder: Characteristics of Extruded Starch Polymers , 1984 .

[13]  J. L. Willett,et al.  Rheology of thermoplastic starch: Effects of temperature, moisture content, and additives on melt viscosity , 1995 .

[14]  G. Griffin.  STARCH POLYMER BLENDS , 1994 .

[15]  D. Göritz,et al.  Investigations on High Amylose Corn Starch Films. Part 1: Wide Angle X-Ray Scattering (WAXS) , 1994 .

[16]  W. Doane,et al.  Development of Starch Based Plastics - A Reexamination of Selected Polymer Systems in Historical Perspective , 1993 .

[17]  W. Wiedmann,et al.  Compounding of Thermoplastic Starch with Twin-screw Extruders , 1991 .

[18]  M. Hisamatsu,et al.  GPC Profile Change of Potato Starch with Extrusion Processing , 1990 .

[19]  Harald Röper,et al.  The Role of Starch in Biodegradable Thermoplastic Materials , 1990 .

[20]  Bienvenido O. Juliano,et al.  Thermal characterization of rice starches: a polymeric approach to phase transitions of granular starch , 1986 .

[21]  R. Hoseney,et al.  Heat-Burst Calorimetry of Heated Starch† , 1986 .

[22]  P. Colonna,et al.  Macromolecular modifications of manioc starch components by extrusion-cooking with and without lipids , 1983 .