Upgrading brewer's spent grain as functional filler in polypropylene matrix

Abstract

Brewer's spent grain (BSG) is a by‐product of the brewing industry that contributes to a large volume of wastes. The lignocellulosic nature of this waste, together with presence of functional components such as antioxidants, represents an attractive for the composite's industry. In this work, BSG has been used as functional filler for polypropylene matrix to give an additional use to this industrial waste. Addition of BSG filler improves the overall environmental efficiency of the polypropylene matrix thus leading to high environmentally friendly materials. BSG can be loaded in the 10–40 wt% range with easy manufacturing, balanced mechanical properties, and additionally, excellent antioxidant properties are achieved with increasing BSG loading due to natural antioxidants that have not been removed during the brewing process. In particular, the onset of the thermo‐oxidative degradation of polypropylene is improved by 15–20°C for different compositions. Due to the lignocellulosic nature of BSG, water uptake is a clear drawback of PP–BSG composites but formulations containing 10‐30 wt% BSG hold the water uptake at very low values. POLYM. COMPOS., 38:40–47, 2017. © 2015 Society of Plastics Engineers

More than just a beer—the potential applications of by-products from beer manufacturing in polymer technology

“…Revert et al [164] introduced the BSG as a filler into the polypropylene matrix. Nevertheless, due to the polarity differences between filler and matrix, the interfacial interactions were fragile, and the significant deterioration of mechanical performance was noted.…”

Processing and Characterization of Environmentally Friendly Composites from Biobased Polyethylene and Natural Fillers from Thyme Herbs

“…Most compatibilizers consist on copolymers with dual functionality: non-polar segment chains and polar groups. This allows establishing interactions with both the polymer matrix (the hydrophobic segment chains) and the lignocellulosic particles (the hydrophilic/polar groups) [34,35].…”

Developing thermoplastic corn starch composites filled with brewer's spent grain for applications in biodegradable films

“…This composition was chosen based on previous studies, [41] which resulted in homogeneous and flexible films. TPS/BSG composites (C) were prepared by adding different contents (1, 2.5, and 5 wt%) of BSG sifted with different sieves (35,60, and 100 mesh). The amount of deionized water was reduced in order to keep the final weight of the mixture at 100 g, as shown in Table 2.…”

“…[27] Another recent option for sustainable use of BSG is as a filler or reinforcement in polymer composites, as summarized in Table 1. As can be observed, different contents of BSG have been explored with different polymer matrices, including polycaprolactone, [32,33] polyhydroxy(butyrate-covalerate), [34] polypropylene, [35] polyurethane, [36] and others. Among them, only two studies explored the use of TPS as a polymer matrix, using cassava and potato starch to produce biodegradable foam trays.…”

“…In this context, the purpose of this study was to develop films of thermoplastic corn starch filled with BSG. We explored the use of different contents (1-5 wt%) of BSG fibers with different sizes (35,60, and 100 mesh), aiming to identify the film compositions with the most promising mechanical and thermal properties. The composites developed in the present study are sustainable and consist of alternatives to conventional polymer materials based on fossil sources.…”