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Rheological characterization of starch derivatives/polycaprolactone blends processed by reactive extrusion
Author(s) -
Bossard Frédéric,
Pillin Isabelle,
Aubry Thierry,
Grohens Yves
Publication year - 2008
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.21160
Subject(s) - materials science , compatibilization , reactive extrusion , starch , rheology , shear rate , composite material , oligomer , extrusion , viscoelasticity , thermoplastic , chemical engineering , shear thinning , polymer blend , polymer chemistry , polymer , copolymer , organic chemistry , chemistry , engineering
Linear viscoelastic, steady shear behaviors, and morphologies of starch formate/poly(ε‐caprolactone) (PCL) blends, compatibilized by oligomers and obtained by reactive extrusion, have been investigated as a function of formic acid (FA)/starch ratio, nature, and molecular weight of the oligomer. The rheological properties of these blends have been compared with those of a commercial starch‐based thermoplastic, namely Mater‐Bi® ZF03UA. In presence of FA, starch is destructured to starch formate and oligomers are used as plasticizers. The linear viscoelastic response of blends is quite similar to that of nanocomposite materials: the low frequency behavior is attributed to a percolated network of destructured starch particles, and the high frequency behavior is that of the polymer matrix. The viscosity curve presents a profile characterized by two plateau regions, at low and high shear rates. The plateau region at low shear rates corresponds to the viscous response of the blend while that observed at high shear rates can be attributed to the PCL matrix. The compatibilization is enhanced in the presence of starch formate and increases with increasing the oligomer molecular weight. The use of PCL oligomer was shown to improve this compatibilization effect. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers