Influence of ionic plasticizers on the processing and viscosity of starch melts

Paul Decaen (1, 2, 3) , Agnès Rolland-Sabaté (1, 4, 3) , Gael Colomines (5, 3) , Sophie Guilois (1, 3) , Denis Lourdin (1, 3) , Guy Della Valle (1, 3) , Eric Leroy (6, 3)

1 BIA - Unité de recherche sur les Biopolymères, Interactions Assemblages
2 GEPEA - Laboratoire de génie des procédés - environnement - agroalimentaire
3 IBSM - Institut de biologie structurale et microbiologie
4 SQPOV - Sécurité et Qualité des Produits d'Origine Végétale
5 GEPEA-MAPS2 - Matrices Aliments Procédés Propriétés Structure - Sensoriel
6 GEPEA - Laboratoire de génie des procédés - environnement - agroalimentaire

Maize starch was plasticized by glycerol, choline chloride ([Chol][Cl]) and ionic liquids (Choline acetate ([Chol][Ace]), 1-Ethyl-3-methylimidazolium Chloride ([EMIM][Cl]) and 1-Ethyl-3-methylimidazolium acetate ([EMIM][Ace]). Melt rheology at 120 °C was assessed with a twin-screw micro-compounder used for processing small quantities (8−10 g), and with a capillary rheometer with pre-shearing (Rheoplast). Qualitative agreement was found between shear viscosities obtained by both rheometry devices, showing the interest of the micro-compounder for screening of plasticizers’ influence. The lower shear viscosity values were obtained in presence of [EMIM][Ace] whereas [Chol][Cl] led to the largest ones. Rather than processing induced macromolecular degradation, the glass transition temperature depressing effect of the plasticizers was found to better explain viscosity differences. This underlines the strong influence of the nature of the plasticizers on starch melt rheology. Finally, results from extensional viscosity shows the specific influence of [EMIM][Ace], suggesting that this plasticizer could be particularly relevant for thermoplastic starch processing.

Mots clés: Thermoplastic starch; Glass transition; glass

Domaines: Génie des procédés; Polymères

Paul Decaen, Agnès Rolland-Sabaté, Gael Colomines, Sophie Guilois, Denis Lourdin, et al.. Influence of ionic plasticizers on the processing and viscosity of starch melts. Carbohydrate Polymers, 2020, 230, pp.1-11. ⟨10.1016/j.carbpol.2019.115591⟩. ⟨hal-02548900⟩