Biocomposites Based on Plasticized Wheat Flours: Effect of Bran Content on Thermomechanical Behavior

Abstract

In the present work, the effect of different bran content on the overall thermomechanical behavior of plasticized wheat flours (thermoplastic wheat flour; TPWF) was investigated. Refined flour (F0) with negligible bran fiber content, F1 flour (whole grain flour, 20% wt. bran), F3 (50% wt. bran) and F2 (F1:F3, 50:50) film samples were realized by extrusion process. The effect of TPWF blending with two different biopolymers (polycaprolactone and poly butyrate adipate terephthalate), combined with the presence of citric acid as compatibilizer was also considered. Results from FESEM analysis and tensile characterization demonstrated that PCL was able to reach improved compatibility with the plasticized flour fraction at intermediate bran content (F2 based formulation) when 25% wt. of biopolymeric phase was added. Additionally, it was proved that improvements can be achieved in both thermal and mechanical performance when higher shear rate (120 rpm) and low temperature profiles (Tset2 = 130–135–140 °C) are selected. Disintegrability of the TPWF basic formulations in compositing conditions within 21 days was also confirmed; at the same time, an absence of any phytotoxic event of compost itself was registered. The obtained results confirmed the suitability of these materials, realized by adding different bran contents, to mechanically compete with bioplastics obtained by using purified starches.

Organic waste valorisation towards circular and sustainable biocomposites

“…122 With this aim, Dominici and co-authors proposed the plasticization of wheat flour to realize thermoplastic systems. 123 In this work, the effect of different bran content (refined flour with negligible bran fibre content, whole grain flour (20 wt% bran), higher bran amount (50 wt%)) on the overall thermomechanical behaviour of plasticized wheat flours was investigated. The results evidenced that, within the framework of different prospective EoL solutions, obtained thermoplastic-based systems disintegrated in accelerated composting conditions within 21 days.…”

“…The results confirmed an efficient and eco-suitable use of the proposed material. 123 To name and report a few of the overall modifications for biowaste to biopolymers reported in the literature, marine waste is of special interest. Almanza and co-authors proposed different deacetylation percentages of chitosan available in sand crab carapace: 124 separate treatments were applied to the carapace, and the results in terms of ash, humidity and insoluble matter percentage confirmed the quality of chitosan for potential biomedical applications.…”

Sustainable Management of Organic Waste and Recycling for Bioplastics: A LCA Approach for the Italian Case Study

“…The results show good performance of the product obtained. In general, however, much bioplastic research is focused on the use of starchy-rich and renewable plant materials such as maize [24], potatoes [25], wheat [26], manioc, and vegetable oils [27,28]. However, the production of bioplastics from food precursors, in addition to the fact that it can often be costly, poses a further problem: obtaining bioplastics from food crops means taking away land and water from food production, which should be used for human consumption.…”

Biocomposites Based on Wheat Flour with Urea-Based Eutectic Plasticizer and Spent Coffee Grounds: Preparation, Physicochemical Characterization, and Study of Their Influence on Plant Growth

“…However, there are only a few works related to thermoplastic starch (TPS) with cf or other coffee byproducts [ 46 , 47 , 48 , 49 ]. Additionally, few works described TPWF composites, i.e., with flax [ 50 ], sisal [ 12 ] cotton [ 10 ], or bran fibers [ 51 ], but there are no studies with thermoplastic wheat flour with cf.…”