Biodegradation Behavior of Poly(lactic acid) (PLA)/Distiller’s Dried Grains with Solubles (DDGS) Composites

Abstract

Poly­(lactic acid) (PLA) and distiller’s dried grains with solubles (DDGS) are biobased materials with strong potential for industrial applications. This paper reports the biodegradation behavior of PLA/DDGS (80/20 by weight), a composite material developed for use in high-quality, economical, biodegradable, crop containers for the horticulture industry. Biodegradation experiments were performed in soil under landscape conditions. Surface morphology and thermal properties were evaluated by scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), and differential scanning calorimetry (DSC). We found that adding 20% DDGS to form the PLA/DDGS composite can accelerate the biodegradation rate and enhance the storage modulus compared to pure PLA. The weight loss of the PLA/DDGS composite during 24 weeks of degradation time was 10.5%, while the weight loss of pure PLA was only 0.1% during the same time interval. Cracks and voids caused by erosion and loss of polymer chain length were clearly observed on the surface of the composite material in response to increasing degradation time. The thermal stability of the composite increased with increasing degradation time. The glass transition temperature and melting temperature increased during early stages of biodegradation (up to 16 weeks) and then decreased slightly. We confirm that DDGS can function as a cost-effective biodegradable filler for PLA composites that can provide enhanced mechanical properties with only slight changes in thermal properties when compared to pure PLA.

Preparation and characterization of antistatic packaging for electronic components based on poly(lactic acid)/carbon black composites

“…In Figure (b,e), there is a presence of granules on the surface of the samples; these may be biofilm residues that have rested after washing, or some other material adhered or deposited during the analysis . Figure (c,f) shows the formation of large spots and some small surface cracks, results similar to that found by the neat PLA biodegradation test . Similar structures can be observed in the 0, 90, and 180 days PLA images and the 10% by weight PLA/carbon black composites with them, which may be associated with the formation of biofilms, once the PLA begins to degrade with 180 days.…”

Novel bioresource‐based poly(3‐Hydroxybutyrate‐co‐4‐Hydroxybutyrate)/poly(LacticAcid) blend fibers with high strength and toughness via melt‐spinning

“…The degree of crystallinity (X c ) of the neat P3HB4HB, PLA, and each phase in the P3HB4HB/PLA blend fibers were calculated from the enthalpy of fusion according to eq. : where ∆ H m is the enthalpy of fusion of each phase calculated from the endothermic peak of the heating curve, is the theoretical enthalpy of fusion for 100% crystalline P3HB4HB (146.6 J/g for P3HB) and PLA (93.7 J/g), and W p is the weight fraction of each phase of the blend fibers. For P3HB4HB/PLA blend fibers, it is necessary to consider the interaction of the two phases.…”

“…The WAXD diffraction spectra were recorded in the 2θ range: 10–50° at a scan rate of 3°/min. The degrees of crystallinity (X c ) of the neat P3HB4HB, PLA, and P3HB4HB/PLA blend fibers were calculated by: where I c and I a are the diffracted intensities of the crystalline and amorphous phases, respectively. The diffracted intensity of the crystalline and amorphous peaks was separated using PeakFit software (vision 4.12) by fitting with the Gaussian‐Lorentzian peak (R 2 ≥ 0.997).…”

The intumescent flame‐retardant biocomposites of poly(lactic acid) containing surface‐coated ammonium polyphosphate and distiller's dried grains with solubles (DDGS)

“…The use of the components from natural agricultural products can reduce waste disposal, agricultural residues, and environmental pollution from the burning of them. Distiller's dried grains with solubles (DDGS) is the byproduct of ethanol production by cereal fermentation process, and the main use of DDGS is animal feeding . The output of DDGS is increasing dramatically in the world, and therefore, it is urgent to find new uses for surplus DDGS .…”

“…Distiller's dried grains with solubles (DDGS) is the byproduct of ethanol production by cereal fermentation process, and the main use of DDGS is animal feeding. 20 The output of DDGS is increasing dramatically in the world, and therefore, it is urgent to find new uses for surplus DDGS. 21 The DDGS has the advantages of renewable sources, low density, low cost, and biodegradability, and the main constituents such as protein In this work, the flame-retardant biocomposites of PLA, surfacecoated DDGS, and APP were prepared.…”