Process for preparing compositions based on a starchy component and on a synthetic polymer

Abstract

Process for preparing a composition based on a synthetic polymer includes: introducing, into a reactor containing a softened or molten synthetic polymer, a non-plasticized starchy component and a plasticizer of the latter; and kneading the mixture obtained under conditions sufficient to obtain the plasticization of the starchy component by the plasticizer, and a homogeneous mixture of the synthetic polymer and of the plasticized starchy component. The reactor may especially be a co-rotating or counter-rotating single-screw or twin-screw extruder, for example a co-rotating twin-screw extruder. The synthetic polymer may advantageously be chosen from the group including polyethylenes (PE) and polypropylenes (PP), which are functionalized or unfunctionalized, polyamides (PA), thermoplastic polyurethanes (TPU), styrene-ethylene-butylene-styrene (SEBS) copolymers, preferably that are functionalized, amorphous polyethylene terephthalates (PETG) and blends thereof. The resulting compositions have improved characteristics, especially in terms of coloration and of mechanical properties, for example in terms of elongation at break.