Premium
The role of protein–plasticizer–clay interactions on processing and properties of thermoplastic zein bionanocomposites
Author(s) -
Nedi I.,
Di Maio E.,
Iannace S.
Publication year - 2012
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.36860
Subject(s) - plasticizer , montmorillonite , materials science , dynamic mechanical analysis , thermoplastic , nanocomposite , thermogravimetric analysis , composite material , chemical engineering , polymer , polymer chemistry , engineering
Bionanocomposites (BNCs) based on thermoplastic zein (TPZ) and unmodified sodium montmorillonite (MMT), at 1, 2.5, 5, and 10 wt % loading, were prepared by using an internal mixer. The nanocomposites were characterized by using the following analytical methods: small‐angle and wide‐angle X‐ray diffraction, thermogravimetric, dynamic‐mechanical and mechanical analyses. Results evidenced that the efficient dispersion of the inorganic reinforcement, as proved by X‐ray diffraction, allowed for an effective improvement of thermal and mechanical properties of the BNCs with respect to the neat TPZ. In particular, a significant increase of the storage modulus in the whole temperature range was observed in dynamic‐mechanical experiments. A dramatic increase of mechanical properties has also been observed, with Young's modulus increasing from 296 MPa for neat TPZ to 1205 MPa at 5 wt % and to 1478 at 10 wt % of MMT. The observed dependencies are explained by means of three concurring mechanisms: (i) the stiffening by exfoliated MMT platelets, (ii) the development of strong interactions between the nanoparticles and the protein macromolecules, promoted by the low‐molecular weight plasticizer, (iii) the occurrence of possible plasticizer sequestration by MMT and the corresponding reduction of plasticizing effect on the protein. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012