Effect of Almond Shell Waste on Physicochemical Properties of Polyester-Based Biocomposites

Abstract

Polyester-based biocomposites containing INZEA F2® biopolymer and almond shell powder (ASP) at 10 and 25 wt % contents with and without two different compatibilizers, maleinized linseed oil and Joncryl ADR 4400®, were prepared by melt blending in an extruder, followed by injection molding. The effect of fine (125–250 m) and coarse (500–1000 m) milling sizes of ASP was also evaluated. An improvement in elastic modulus was observed with the addition of< both fine and coarse ASP at 25 wt %. The addition of maleinized linseed oil and Joncryl ADR 4400 produced some compatibilizing effect at low filler contents while biocomposites with a higher amount of ASP still presented some gaps at the interface by field emission scanning electron microscopy. Some decrease in thermal stability was shown which was related to the relatively low thermal stability and disintegration of the lignocellulosic filler. The added modifiers provided some enhanced thermal resistance to the final biocomposites. Thermal analysis by differential scanning calorimetry and thermogravimetric analysis suggested the presence of two different polyesters in the polymer matrix, with one of them showing full disintegration after 28 and 90 days for biocomposites containing 25 and 10 wt %, respectively, under composting conditions. The developed biocomposites have been shown to be potential polyester-based matrices for use as compostable materials at high filler contents.

Effect of Lemon Waste Natural Dye and Essential Oil Loaded into Laminar Nanoclays on Thermomechanical and Color Properties of Polyester Based Bionanocomposites

“…Figure 6 c,d shows the DSC thermograms obtained during the DSC cooling and second heating scans for all formulations. Two different peaks were observed for neat INZEA, indicating the presence of two main polyesters in the polymer matrix, in agreement with the behavior previously observed by Ramos et al [ 58 ]. The analysis of the experimental curves indicated that no substantial variations were introduced in the glass transition temperatures, while the main effect was related to the shift of melting and crystallization temperatures, in parallel with the evidence or disappearance of multiple melting peaks.…”

“…In particular, the curves related to mass loss (a) and derivative weight loss (b) for the system containing 7 wt% of nanopigments (representative of the same trend observed for the formulations containing 3 and 5 wt% of nanopigments) are reported in Figure 6 a,b. As it has been reported [ 58 ], a double degradation peak can be found for the INZEA neat matrix, with two main steps centered at 350 and 400 °C, that could match with the possible degradation temperatures of PLA and poly(butylene succinate) (PBS) polyesters, respectively. It is also important to note that at 900 °C, unmodified INZEA matrix maintained a residual mass of ca.…”

Anthocyanin Hybrid Nanopigments from Pomegranate Waste: Colour, Thermomechanical Stability and Environmental Impact of Polyester-Based Bionanocomposites

“…5 wt% at 900 • C, which was increased when the nanofillers were introduced. This behaviour is in accordance with the possible presence of an inorganic filler in the formulation of the commercial product, as it has been reported in other work [62].…”

Effect of Mineral Fillers on the Mechanical Properties of Commercially Available Biodegradable Polymers

“…Although the main academic focus of biodegradable polymer reinforcement in recent years has been on the use of organic natural fillers [18][19][20], the use of inorganic mineral fillers such as talc [21,22], calcium carbonate [23,24], kaolin [25,26], and mica [27,28] and their impact on the biodegradability of these polymers [29][30][31] has been investigated as well. As the properties of particulate polymer composites can highly fluctuate strongly, due to variations in additional polymer additives, processing techniques, and the applied test methods, it is generally complex to compare individually reported results [32][33][34]. Therefore, this work is a comparative study on the effect of various particulate fillers (talc, calcium carbonate, kaolinite, mica) on the most important mechanical properties of a selected number of industrially available biodegradable polymers (PBS, PBSA, PHBH, and PBAT) while keeping all other factors constant.…”