Urea and ethanolamine as a mixed plasticizer for thermoplastic starch

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;…”

“…TPS materials have been prepared using casting process (Mathew & Dufresne, 2002;Parra, et al, 2004;Mali et al, 2005;Chand et al, 2006;Talja et al, 2007;Talja, 2008) or by melt mixing in batch, internal mixer (Forssell et al 1997;Da Roz et al, 2006;Teixeira et al, 2007), or continuous equipment such as single (Souza & Andrade, 2002;Ma & Yu, 2004a;Ma & Yu, 2004b;Ma et al, 2006) or twin-screw extruders (RodriguezGonzalez et al, 2003a;Rodriguez-Gonzalez et al, 2003b;You et al, 2003;RodriguezGonzalez et al, 2004;Tena-Salcido et al, 2008;Chaudhary, 2010;Mendez-Hernandez et al, 2011). In the case of melt mixing processes, starch, plasticizer and water have been fed as dry blends (Ma & Yu, 2004a;Ma & Yu, 2004b;Da Roz et al, 2006;Ma et al, 2006;Chaudhary, 2010) or slurries (Rodriguez-Gonzalez et al, 2003a;Rodriguez-Gonzalez et al, 2003b;RodriguezGonzalez et al, 2004;Tena-Salcido et al, 2008;Mendez-Hernandez et al, 2011). 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.…”

“…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.…”

Understanding the role of water-ionic liquid mixtures on the gelatinization and dissolution of maize starches

“…In some cases, a combination of two or more plasticizers is also used to optimize the advantages and eliminate some disadvantages associated with the individual plasticizers. For instance, a blend of urea and ethanolamine could facilitate the formation of stable and strong hydrogen bonds between starch molecules which could also prevent urea from separating out (Ma, Yu & Wan, 2006). In another study, Yu, Wang & Ma (2005), found that citric acid added to a mixture of glycerol and water enhanced the thermal stability, elongation and water resistance of plasticized starch.…”

“…On cooling, the starch chains (amylose and amylopectin) in the gelatinized paste associate, leading to the formation of a more ordered structure. Other plasticizers reported to have improved the processing properties and product performance of thermoplastic starch are glycerol (Thuwall, Boldizar & Rigdahl, 2006;Follain et al, 2006;Yu, Wang & Ma, 2005), glycol, sorbitol (Da Roz, Carvalho, Gandini & Curvelo, 2006, sugars (Teixeira, Dar Roz, Carvalho & Curvelo, 2007), urea (Ma, Yu & Wan, 2006), formamide , acetamide , ethylenebisformamide , ethanolamine (Ma, Yu & Wan, 2006) and citric acid (Yu, Wang & Ma, 2005). In some cases, a combination of two or more plasticizers is also used to optimize the advantages and eliminate some disadvantages associated with the individual plasticizers.…”