Structure and Mechanical Behavior of Fully Substituted Acid Starch Esters

Abstract

AbstractThis study deals with the evolution of structural, thermal, and mechanical properties of a series of fully substituted fatty acid starch esters (FASEs) according to side chain length (from 2 (C2) up to 16 (C16) Carbons). FASEs with C2 to C12 side chains are fully amorphous with a glass transition temperature depending on chain length while in the case of FASE with C16 side chains, a part of side chains is able to crystallize. Thermomechanical behavior depends strongly on both the alkyl chain length and crystallinity of samples. In particular, for FASE‐C16, the presence of crystals leads to a brittle behavior. During stretching, no macromolecular orientation is evidenced for short‐chain FASEs (<C8), whereas, for long‐chain starch ester from C8 to C16 length, an orientation of starch backbone in the drawing direction is observed.