caa a22 4500 445384824 CHVBK 20180317143029.0 cr unu---uuuuu 170323e20110901xx s 000 0 eng 10.1007/s10924-011-0307-3 doi (NATIONALLICENCE)springer-10.1007/s10924-011-0307-3 Thermoplasticization of High Amylose Starch by Chemical Modification Using Reactive Extrusion [Elektronische Daten] [Jacqueline Stagner, Vanessa Dias Alves, Ramani Narayan, Adelaide Beleia] Modified thermoplastic high amylose starch (MTPS) was synthesized by reactive extrusion in the presence of maleic anhydride (MA) as an esterification agent in a twin-screw extruder. The objective of this work was the preparation of reactive thermoplastic starch in the presence of glycerol and with different amounts of maleic anhydride (MA) and free-radical initiator, in order to improve processability and reactivity. The concentration of MA added varied from 2 to 6 wt% (of starch+glycerol), and the free-radical initiator, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, also called Luperox 101, varied from 0.1 to 0.5 wt% (of starch+glycerol). Characterization of maleated thermoplastic starch was performed using dynamic light scattering and thermal analysis. Further, proof of chemically modified extrudate was determined by Fourier transform infrared spectroscopy and by soxhlet extraction with acetone. The modified high amylose corn starch (20 or 30% glycerol) could be pelletized and gave pellets that were more transparent than thermoplastic starches not modified with maleic anhydride. There was negligible change in hydrodynamic radius as the percentage of maleic anhydride increased. However, as the percentage of Luperox 101 increased, the hydrodynamic radius decreased. It could be inferred that the molecular weight decreased as the percentage of free-radical initiator increased. Using the maximum temperature in the extrusion process of 165°C instead of 135°C caused a decrease in the hydrodynamic radius, due to the high influence of the temperature profile on the molecular weight of the thermoplastic starch. The MTPS samples presented higher melting temperatures compared to TPS samples. The soxhlet studies indicated that the plasticizer, glycerol, was chemically linked to the starch. Using the maximum temperature of 165°C versus 135°C in the extrusion temperature profile resulted in more interaction between glycerol and starch. Springer Science+Business Media, LLC, 2011 Biodegradable nationallicence Thermoplastic starch nationallicence Maleation nationallicence Reactive extrusion nationallicence Stagner Jacqueline Biobased Material Research Group (BMRG), Michigan State University, East Lansing, MI, USA aut Dias Alves Vanessa Departamento de Ciência e Tecnologia de Alimentos, Universidade Estadual de Londrina, Londrina, PR, Brazil aut Narayan Ramani Biobased Material Research Group (BMRG), Michigan State University, East Lansing, MI, USA aut Beleia Adelaide Departamento de Ciência e Tecnologia de Alimentos, Universidade Estadual de Londrina, Londrina, PR, Brazil aut Journal of Polymers and the Environment Springer US; http://www.springer-ny.com 19/3(2011-09-01), 589-597 1566-2543 19:3<589 2011 19 10924 https://doi.org/10.1007/s10924-011-0307-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10924-011-0307-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Stagner Jacqueline Biobased Material Research Group (BMRG), Michigan State University, East Lansing, MI, USA aut NATIONALLICENCE 700 1- Dias Alves Vanessa Departamento de Ciência e Tecnologia de Alimentos, Universidade Estadual de Londrina, Londrina, PR, Brazil aut NATIONALLICENCE 700 1- Narayan Ramani Biobased Material Research Group (BMRG), Michigan State University, East Lansing, MI, USA aut NATIONALLICENCE 700 1- Beleia Adelaide Departamento de Ciência e Tecnologia de Alimentos, Universidade Estadual de Londrina, Londrina, PR, Brazil aut NATIONALLICENCE 773 0- Journal of Polymers and the Environment Springer US; http://www.springer-ny.com 19/3(2011-09-01), 589-597 1566-2543 19:3<589 2011 19 10924 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer