Eco-Conversion of Two Winery Lignocellulosic Wastes into Fillers for Biocomposites: Vine Shoots and Wine Pomaces

Abstract

<jats:p>Two winery residues, namely vine shoots (ViSh) and wine pomace (WiPo), were up-cycled as fillers in PHBV-based biocomposites. Answering a biorefinery approach, the impact of a preliminary polyphenols extraction step using an acetone/water mixture on the reinforcing effect of fillers was assessed. Biocomposites (filler content up to 20 wt%) were prepared by melt-mixing and compared in terms of final performance (thermal, mechanical and barrier). It was shown that the reinforcing effect was slightly better in the case of vine shoots, while it was not significantly affected by the pre-treatment, demonstrating that these two winery residues could be perfectly used as fillers in composite materials even after an extraction process to maximize their potential of valorization.</jats:p>

Using life cycle assessment to quantify the environmental benefit of upcycling vine shoots as fillers in biocomposite packaging materials

“…It was previously shown that increasing the content of ViSh in PP (Girones et al 2017), PE (Girones et al 2017), or PHBV (David et al 2020b) resulted in a slight decrease of the mechanical properties of the materials. Ahankari et al (2011) studied the reinforcement of PHBV and PP with agroresidues and recommended to incorporate filler contents lower than 40 wt% to avoid a decrease in mechanical properties, due to an increased filler agglomeration in the polymer matrix.…”

Wine By-Products as Raw Materials for the Production of Biopolymers and of Natural Reinforcing Fillers: A Critical Review

“…[ 36 ]), to enhance up to 65% the elastic modulus of PLA, and, exploiting the micro-mechanical models of Voigt and Halpin–Tsai, they also calculated that grape stalks had an intrinsic elastic modulus ( E f ) of 6.8–9.0 GPa. David et al [ 34 ] tested both vine shoots and grape pomace as reinforcing fillers within PHBV and they noticed that vine shoots were able to increase the Young’s modulus (up to 16%) while grape pomace did not affect this property. Indeed, grape pomace is poor in cellulose (10%) and hemicellulose (6%) and particularly rich in lignin (35–42%) which, contrary to cellulose and hemicellulose, acts more as a coupling agent (between cellulose and hemicellulose) rather than as a stiffening element [ 160 ].…”

“…Since degradation temperatures ( T deg ) of wine by-products are in the 200–270 °C range, while those of PLA, PBS, and PHB are at around, 330, 340, and 290 °C, respectively, the thermal stability of the resulting composites are generally lower thermal than ones of the neat biopolymers. For example, PLA and grape pomace composites start to degrade at around 255 °C (−75 °C with respect to pure PLA) [ 149 ] and PHBV filled by vine shoots or grape pomace has shown a T deg at around 265–270 °C (−12°C with respect to neat PHBV) [ 34 ]. Considering PBS biopolymer, the addition of 40 %wt.…”

“…David et al [ 34 ] investigated the water vapor permeability (WVP) of composites formed by PHBV and vine shoots or grape pomace at different percentages (5, 10, and 20 %wt.). They reported that WVP of wine-based composites was significantly higher (up to five times) than that of neat PHBV and they mainly explained this result as a consequence of the high hydrophilic character of wine wastes.…”

Integrated Efforts for the Valorization of Sweet Potato By-Products within a Circular Economy Concept: Biocomposites for Packaging Applications Close the Loop

“…One common way to overcome these drawbacks is to mix these biopolymers with suitable additives or fillers to obtain biocomposites. Some reports in the literature attempt to enhance the physical and mechanical properties of PHBV or other biopolyesters by blending or filling techniques, using different types of natural fibres [ 21 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ] or wastes from agro-industrial processing [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ].…”