CONICET | Buscador de Institutos y Recursos Humanos

The use of native starch as a thermoplastic polymer is limited by its fragility and high water absorp- tion. Due to the presence of several hydroxyl groups in its structure, water acts as a natural plasticizer of starch, modifying its properties. It is necessary to chemically modify starch molecules by replacing hydroxyl groups with other functional groups to reduce water absorption. Chemical modiﬁcation of starch granules also alters its swelling and gelatinization behavior. In this contribution we describe the chemical modiﬁcation of starch and its inﬂuence on its hydrophilicity and heat resistance. Acetic acid, maleic anhydride and octanoyl chloride were used as derivatizing reagents. The effectiveness of the treatments was evaluated by means of infrared spectroscopy. Different tests were conducted in order to evaluate the inﬂuence of the different chemical modiﬁcations on starch structure and properties. Results showed that the treatments effectively reduced starch moisture susceptibility, while substantially altering other properties such as amylose content, swelling power, solubility, and heat resistance. Finally, ﬁlms were prepared from native and derivatized starch and their sur- face polarity was evaluated.