Investigation of the gelatinization and extrusion processes of corn starch

Abstract

ABSTRACT:The gelatinization and extrusion processes of corn starch were studied. Differential scanning calorimetry was used to determine the gelatinization temperature as a function of the water content. Plasticized corn starch was processed in single-and twin-screw extruders to produce thermoplastic materials. The mechanical properties of the films obtained in the twin-screw extruder with the addition of different quantities of water were evaluated. Dynamic mechanical analysis applied to thermoplastic starch samples obtained with 33% (w/w) total plasticizers showed two transitions, attributed to the presence of two phases in the starch-glycerol-water system.

Modeling of bubble growth dynamics and nonisothermal expansion in starch‐based foams during extrusion

“…Starch has been regarded as one of most promising raw materials to produce biodegradable thermoplastics. [1][2][3][4][5][6] Starch-based foam is a lightweight biodegradable thermoplastic material, which can be used in packaging. 7,8 Extrusion is able to produce starch-based foam continuously.…”

Effect of natural fibres on the mechanical properties of thermoplastic starch

“…These factors were also reported by other researchers. Extrusion-cooking may also be some kind of thermal modification processing as it changes the chemical structure of starch chains, viscosity, solubility, and the microstructure of extruded materials (Camire et al, 1990;Hagenimana et al, 2006;Souza and Andrade, 2002).…”

“…The issue of using starch of different origin (mostly maize, wheat, potato, tapioca) for the production of TPS biodegradable packaging materials is discussed in numerous scientific papers (Chen and Evans, 2005;Cyras et al, 2008;Huang et al, 2004Huang et al, , 2005Souza and Andrade, 2002). This type of biodegradable products may be complementary to alternative plastics; however, they do not have a wide application due to certain defects ie brittleness, retrogradation, and hygroscopic properties (Averous and Boquillon, 2004;Mitrus and Mościcki, 2009;Ray et al, 2007;Thomas and Atwell, 1997).…”

Melt Blending with Thermoplastic Starch

“…Utilization of plasticizers other than water helps to stabilize the properties of TPS. The main plasticizer used in TPS composition is glycerol (Forssell et al 1997;Mathew & Dufresne, 2002;Souza & Andrade, 2002;Ma & Yu, 2004a;Ma & Yu, 2004b;Parra et al, 2004;Rodriguez-Gonzalez et al, 2003a;Rodriguez-Gonzalez et al, 2003b;Rodriguez-Gonzalez et al, 2004;Mali et al, 2005;Chand et al, 2006;Ma et al, 2006;Teixeira et al, 2007;Talja et al, 2007;Talja et al, 2008;Tena-Salcido et al, 2008;Chaudhary, 2010;Mendez-Hernandez et al, 2011) but other alcohols (Da Roz et al, 2006), polyols (Mathew & Dufresne, 2002;Parra et al, 2004;Mali et al, 2005;Da Roz et al, 2006;Talja et al, 2007;Chaudhary, 2010), sugars (Da Roz et al, 2006;Teixeira et al, 2007;Talja, 2008) or nitrogen compounds such as ethanolamine (Ma et al, 2006), formamide (Ma & Yu, 2004a;Ma & Yu, 2004b), acetamide (Ma & Yu, 2004a) or urea (You et al, 2003;Ma et al, 2006) have also been successfully employed. TPS materials have been prepared using casting process (Mathew & Dufresne, 2002;Parra, et al, 2004;Mali et al, 2005;Chand et al, 2006;…”

“…In some cases, TPS materials prepared by melt mixing have a significant water content which limits the processing temperature far below the processing conditions of most synthetic polymers, i.e. >150˚C, in order to avoid water vapor bubbles into TPS extrudates (Souza & Andrade, 2002;Farhat et al, 2003;Ma et al, 2006;Chaudhary, 2010). The development of an extruder configuration having a venting zone after both starch gelatinization and plasticization processes were accomplished and before exiting from the die allowed the preparation of water-free TPS (Favis et al, 2001;Favis et al, 2003.…”