Mechanical and morphological characterization of starch/zein blends plasticized with glycerol

Abstract

Blends of starch and zein plasticized with glycerol were prepared by melting in a batch mixer at 160°C. Glycerol was used as plasticizer in contents ranging from 20 to 40 wt % with respect to the starch/zein matrix. These blends were characterized by mechanical tests, dynamic mechanical analysis, and optical microscopy. In tensile tests, the Young's modulus and ultimate tensile strength increased with increasing zein content for all compositions, whereas elongation at break decreased sharply with increasing zein content up to 20%, and it remained nearly constant at higher contents of zein, which increased the stiffness of the blends. On the other hand, increase in the glycerol content caused a decrease in mechanical resistance of the blends. Storage modulus increased with increasing zein content and the tan ␦ curves showed that the blends exhibited two distinct glass transitions, one for each component, indicating a two-phase system, confirming the morphological evidence of micrographs that displayed two separate phases.

3D printing of maize protein by fused deposition modeling

“…2-a). Such results are in the same range as those previously published in the literature [12]. Compositions containing 10% glycerol added, or without plasticizer, do not present such an important decrease of storage modulus, limiting their flowing abilities in the molten state above T g , and then avoiding their application in 3D printing by FDM.…”

“…Accordingly, they constitute amphiphilic polymers that can be thermoplasticized after blending with polar or apolar plasticizers. As an example, in a previous study for a content of 22% glycerol (w/w), it presents a main mechanical relaxation linked to its glass transition temperature at about T α =60°C, and a storage modulus (E') about 1GPa at ambient conditions [12,13]. Plasticized zein, added with paracetamol as active ingredient, has been recently considered as extruded-molded caplets for controlling drug release [14].…”

Perspectives of Chitin and Chitosan Nanofibrous Scaffolds in Tissue Engineering

“…Zein is a relatively straightforward biopolymer to electrospin (Miyoshi, Toyohara, & Minematsu, 2005;Torres-Giner et al, 2008b). Additionally, zein has low toxicity and has also being studied in a broad range of areas, such as the food, pharmaceutical, and biodegradable plastics industry (Corradini et al, 2006). Torres-Giner et al, 2009 developed novel antimicrobial ultrathin structures of zein/chitosan blend by electrospinning for biomedical applications.…”

Influence of addition of silanized nanosilica and glycerol on hydrophobicity of starch using a factorial design

“…The search for new polymeric materials, mainly the ones that derivate from renewable sources, has been the reason for the realization of diverse studies [1][2][3][4] . A material with promising potential for that end is the starch, for its raw material is very accessible in many parts of the world.…”

“…A material with promising potential for that end is the starch, for its raw material is very accessible in many parts of the world. Besides that, in general, it is obtained with low costs, being used at the formation of blends or composites with polymeric materials [1][2][3][4][5][6] .…”