Mechanical and barrier properties of thermoplastic whey protein isolate/ethylene vinyl acetate blends

Abstract

Crude oil is becoming scarcer and more expensive, resulting in alternative biobased or partially biobased materials gaining importance in the field of plastic packaging and encouraging the development of naturally derived, protein-based plastics (Endres, 2009; Jones and McClements, Compreh. Rev. Food Sci. Food Safety 2010, 9, 374; Khwaldia et al., Compreh. Rev. Food Sci. Food Safety 2010, 9, 374). A strategy to improve extrusion processing behavior of proteins is the blending with other polymers. In this study ethylene vinyl acetate (EVA) was used for such purpose. The aim of this study was to determine the properties of blends of thermoplastic whey protein (TPP) and ethylene vinyl acetate (EVA). Mechanical and barrier properties were tested. Blends of differing TPP/EVA ratio were produced and extruded into flat films. Morphological analysis of the blends shows immiscibility of the TPP and EVA, greatly influencing the mechanical properties. Young's modulus measurements shows the values approached that of pure EVA with increasing EVA ratios. At values of about 21 MPa, corresponding to EVA ratios of 30% (w/w) and above, continuous extrusion including material take-off was possible. At higher whey protein ratios in the blends the water vapor transmission rate increased, i.e., the higher water vapor transmission rate of whey protein compared with EVA dominated this property. This study showed that whey proteins can be utilized for extrusion by blending with EVA

Influence of sorbitol on mechanical and physico-chemical properties of soy protein-based bioplastics processed by injection molding

“…Moreover, SPI-based probes do not experiment a noticeable decrease in σ max when after adding SB an increase in E takes place. Interestingly, this mechanical response is different to that one previously found by Felix et al [10,19] and Rombouts et al [20] , however are in consonance with the mechanical properties found by Schmid et al [21] and Tummala et al [22] In any case, these elastic responses are consistent with the results from DMTA that showed lower elastic modulus (E') for the system without SB (Figure 2A). These results indicate the feasibility of modulating mechanical properties of bioplastics where mechanical properties obtained after changing the plasticizer used are suitable for different applications.…”

State of the Art in the Development and Properties of Protein-Based Films and Coatings and Their Applicability to Cellulose Based Products: An Extensive Review

“…The possibility of better controlling the processing properties of whey protein by blending it with poly(ethylene-co-vinyl acetate) (EVA) was evidenced by Schmid et al [105]. In fact they succeeded in preparing flexible flat die continuously extruded films from plasticized whey protein blended with EVA.…”

Characterization ofJatropha curcasL. Protein Cast Films with respect to Packaging Relevant Properties

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