Extruded Poly(ethylene–co–vinyl alcohol) Composite Films Containing Biopolymers Isolated from Municipal Biowaste

Abstract

Single-screw extrusion allows obtaining composite films containing poly(ethylene-co-vinyl alcohol), hereinafter EVOH, and water-soluble lignin-like biopolymers (SLP) isolated from the alkaline hydrolysate of two materials sampled from an urban waste treatment plant. During extrusion, a condensation reaction occurs between the EVOH and SLP. The products are heterogeneous. They contain a mix of EVOH-SLP copolymers with different composition and solubility properties. The films were characterized for tensile strength and water sorption properties. Young modulus and strain at break, respectively, were 2.8 GPa and 14 % for neat EVOH vs. 2.1-0.9 GPa and 17-4 % for the blends containing 2-15 % SLP, with values decreasing upon increasing the % SLP. The blends were more hydrophilic than neat EVOH; their water sorption capacity was found to increase upon increasing the SLP content. Compared to previously reported similar blends obtained by twin-screw extrusion and solvent casting, the data for the single-screw extruded films allows discussing several aspects connected to the valorisation of blends obtained from fossil and biowaste sourced polymers.

Ecofriendly manure anaerobic digestion assisted by soluble bio-based substances obtained from anaerobic digestion, composting and chemical hydrolysis of urban bio-wastes. A step toward the integration of urban and agriculture waste management

“…It can be oxidized only by strong reagents. A most recent work reports that the ozonation of SBO opens the aromatic lignin moieties yielding poly hydroxyl carboxylic aliphatic moieties, but negligible mineralization. Thus, the SBO biochemical, chemical and thermal stability is relatively high.…”

“…The product can be recovered upon acidification of the fermentation digestate in high yields, relatively to the added amounts at the start of fermentation. In the dry state, the SBO is stable up to 200 °C . It can be melt extruded at this temperature to yield poly(ethylene‐co‐vinyl alcohol) composite films .…”

“…They are associated with the SBO properties as surfactants, agents for sequestering or carrying small molecules and mineral ions in solution, photosensitizers and reactive biopolymers. Particularly interesting is previous work reporting the performance of SBO as plant growth biostimulants, biopolymers for the fabrication of mulch films for agriculture use, and animal feed supplement . In this context, assessing the SBO performance in reducing ammonia in the digestate obtained from farm manure fermentation represented a further demonstration that integrated chemical and biochemical technology could effectively realize a virtuous, cost‐effective, environmentally friendly and socially favored renewable organic C cycle involving urban and farm biomass and wastes.…”

Isolation, Characterization, and Environmental Application of Bio-Based Materials as Auxiliaries in Photocatalytic Processes

“…In order to follow the EU dictates, several studies in this topic are involved in the valorization of biowaste as starting materials for the production of new value-added products, such as fine chemicals [15][16][17], polymeric (mostly bioplastics) and composite materials [4,[18][19][20][21], carbonaceous materials and biochars [22][23][24][25], biofuels, and/or biogas [26][27][28][29][30]. In this context, composting consists of an (an)aerobic biological process for decomposing the organic fraction into a more stabilized material with different properties that depend on the initial composition [11] and composting methodologies.…”

Aquatic-Derived Biomaterials for a Sustainable Future: A European Opportunity

“…In general, most of the studies in this topic are involved in the valorization of agricultural and/or municipal wastes (mostly lignocellulosic-and starch-based substrates) as starting materials for the creation of new products, especially as fillers or additives in the development of both polymeric and composite materials [7][8][9][10][11][12][13][14][15][16]. This is, for instance, the case of Mater-Bi, a starch-derived commercially-available bioplastic (produced by Novamont S.p.A., Italy) [17][18][19][20].…”