Preparation and Characterization of Thermoplastics Achira (Canna indica L.) Starch by Three Succination Methods

Thermoplastic starches (TPS) from achira, succinated to 3% and 5% octenyl succinate anhydrous (OSA) using aqueous medium, reactive extrusion (REX), and in situ are developed (TPS 3A, TPS 5A, TPS 3R, TPS 5R, TPS 3I, and TPS I5). The physicochemical properties are studied to explore the effect of different methods applied to modified thermoplastic starches. Analysis of infrared spectroscopy and nuclear magnetic resonance of proton shows that the methods used in succination are effective in esterifying starches. REX and the in situ method make it possible to obtain materials with higher degree of substitution (DS), from 0.011 to 0.050, affecting thermoplasticization. The aqueous method promotes greater thermal stability, TPS 3A and TPS 5A are degraded at temperature ranges from 135 to 279 °C and shows a pattern similar to counterpart native TPS 0 (sample control), unlike the REX and the in situ method, both of them beginning degrading at lower temperature values than all starches. Mechanical properties and contact angle are influenced by the processing method and not by DS or glycerol content. All achira TPS developed are a feasible alternative for application in the industry dedicated to the processing of bioplastics.