Influence of Oat Hulls on Biodegradation of Biopolymer from Polylactic Acid

Abstract

The production of biopolymers has been shown to be one of the most viable alternatives for the reduction of the use of conventional plastics. The oat hulls are a by-product with great ability to be incorporated into the production of biopolymers since it is a lignocellulosic compound. The lignin present in its composition can improve the strength of the material, however, it can also hamper its degradation. The aim of this study was to evaluate the degradation levels of composites produced from starch and polylactic acid with absence (T1) and presence of oat hulls (T2) through the Sturm test. In T2 it was a more uniform and smooth biopolymer. In addition, the use of oat hulls favored CO2 production, 8% more than T1. Although the loss of dry mass in T1 was 3% higher, it was possible to observe degradation in T2.

Biodegradable packaging as a suitable protectant for the conservation of frozen pacu ( Piaractus mesopotamicus ) for 360 days of storage at −18°C

“…The same happened with Silva et al. (2020) and Bilck et al. (2021) and this behavior may be due to incomplete gelatinization of the starch present in the films during processing, because the high concentration of starch in the blend.…”

“…The formulations were chosen based on the studies of Silva et al. (2020) with minor modifications. Initially, glycerol (19%) was manually homogenized with PBAT (30%) and cassava starch (51%) (w/w/w).…”

“…Starch is a biodegradable, renewable, and non‐toxic polysaccharide, composed of amylose and amylopectin which varies according to the botanical source (Avérous, 2004; Brandelero et al., 2013). Among the natural starches, cassava starch presents a potential for use in the production of biodegradable films due to its high production and easy access (Campos et al., 2019; Marzano‐Barreda et al., 2020; Medeiros et al., 2019; Silva et al., 2020).…”

Biodegradable Material Formulated With Oat Hulls in the Composting Process of Household Organic Waste and Tree Pruning

“…The formulation of the biodegradable materials (Table 1) was based on Silva et al (2020a) and used cassava starch (General Mills Brasil Alimentos Ltda, Paranavaí, Brazil), poly (lactic acid) (PLA) REVODE® 201-Zhejiang Hisun Biomaterials Co, China), micronized oat hulls (SL Alimentos-Mauá da Serra, Paraná, Brazil) (4.64 g 100 g -1 ash, 3.95 g 100 g -1 protein, 2.12 g 100 g -1 of lipid, 23.13 g 100 g -1 of cellulose, 26.25 g 100 g -1 of hemicellulose and 3.80 g 100 g -1 of lignin) and glycerol (Dinâmica Química Ltda, Brazil). The cassava starch and oat hulls were used because of their low cost compared with pure PLA, and the glycerol was used as a plasticizer (SILVA et al, 2020a). The starch, glycerol, PLA, and oat hull were mixed according to the proportions shown in Table 1 and extruded in a single-screw extruder (BGM,Brazil) to produce cylindrical strands.…”

“…According to the organic waste characterization (Table 2), it was not possible to meet the C/N ratio of 30:1, considered ideal to start the composting process (Kiehl, 1985), because this proportion was impracticable to assembly the reactors and to homogenize the wastes, it means that it would be necessary too much tree pruning. Other studies have also reported good performances in composting organic materials with C/N ratios below 19:1 (Sbizzaro et al, 2017;Silva et al, 2020a). Thus, other C/N ratios were tested, such as 19:1, 18.5:1, and 18:1 (Table 3).…”