Properties of hydric and biodegradability of cassava starch-based bioplastics reinforced with thermally modified kaolin

Namory Méité (1) , Léon Koffi Konan (1) , Monique Tohoué Tognonvi (2) , Bi Irié Hervé Goure Doubi (2) , Moussa Gomina (3) , Samuel Oyetola (1)

1 UFHB - Université Félix Houphouët-Boigny
2 UPGC - Université Péléforo Gon Coulibaly
3 CRISMAT - Laboratoire de cristallographie et sciences des matériaux

In this study, hydric and biodegradability properties of cassava starch-based bioplastics reinforced with crude kaolin or treated kaolinitic clay at 700 °C called metakaolin were investigated using water adsorption and microbiological tests. Non-reinforced bioplastics (BP) and those containing 5 wt.% crude kaolin (BPKB) or metakaolin (BPMKB) were manufactured using the casting/evaporation method. Results obtained showed a decrease in the solubility and in the water diffusion and permeability of clay-reinforced bioplastics with respect to the ones without reinforcement. This improvement of the hydric properties has been attributed to the reduction in the free volumes existing between the starch macromolecules due to their interactions with clay platelets. These interactions might favor a more homogeneous and compact microstructure. The biodegradability of the clay reinforced bioplastics was significantly improved due to the bacterial proliferation. The thermal treatment of kaolinitic clay further improved the hydric and biodegradability properties of starch-based bioplastics.

Mots clés: Cassava starch-based bioplastic; Kaolin; Metakaolin; Hydric properties; Biodegradability

Domaines: Polymères; Matériaux

Namory Méité, Léon Koffi Konan, Monique Tohoué Tognonvi, Bi Irié Hervé Goure Doubi, Moussa Gomina, et al.. Properties of hydric and biodegradability of cassava starch-based bioplastics reinforced with thermally modified kaolin. Carbohydrate Polymers, 2021, 254, pp.117322. ⟨10.1016/j.carbpol.2020.117322⟩. ⟨hal-03456302⟩