PLA/PHB-Based Materials Fully Biodegradable under Both Industrial and Home-Composting Conditions

Abstract

In order to make bioplastics accessible for a wider spectrum of applications, ready-to-use plastic material formulations should be available with tailored properties. Ideally, these kinds of materials should also be “home-compostable” to simplify their organic recycling. Therefore, materials based on PLA (polylactid acid) and PHB (polyhydroxybutyrate) blends are presented which contain suitable additives, and some of them contain also thermoplastic starch as a filler, which decreases the price of the final compound. They are intended for various applications, as documented by products made out of them. The produced materials are fully biodegradable under industrial composting conditions. Surprisingly, some of the materials, even those which contain more PLA than PHB, are also fully biodegradable under home-composting conditions within a period of about six months. Experiments made under laboratory conditions were supported with data obtained from a kitchen waste pilot composter and from municipal composting plant experiments. Material properties, environmental conditions, and microbiology data were recorded during some of these experiments to document the biodegradation process and changes on the surface and inside the materials on a molecular level.

The Potential of Bio-Based Polylactic Acid (PLA) as an Alternative in Reusable Food Containers: A Review

“…However, these laboratory-scale assessments have yielded promising results for the future. LCA studies show mechanical recycling of PLA waste supports the reduction in environmental impacts such as climate change, human toxicity, and fossil fuel depletion [156]. Depending on the quality of PLA waste and regional conditions, all investigated recycling alternatives, namely mechanical recycling, solvent-based recycling, and chemical recycling, are suitable EoL options [157].…”

“…There are, however, a series of standards regarding the labelling of compostable products. They specify tests and requirements that must be carried out and met before a product can be certified as compostable, whether it be in terms of home composting or industrial Once these conditions are met, the process continues at a milder temperature range [156]. The control of both moisture and temperature is a key factor in the degradation of PLA [160].…”

“…Material must not have a negative impact on the compost quality. Once these conditions are met, the process continues at a milder temperature range [156]. The control of both moisture and temperature is a key factor in the degradation of PLA [160].…”

“…Composting studies have been undertaken with PLA blends. PLA/PHB blends at various wt.% were determined to be fully biodegradable under industrial composting conditions [156]. It was found that the disintegration and mineralisation processes could occur in parallel, particularly for thicker pieces of PLA/PHB material, and it was concluded that this blend does not leave microplastics in the compost at the end of the process.…”

Photocatalytic Microplastics “On‐The‐fly” Degradation via Motile Quantum Materials‐Based Microrobots

“…Biodegradable polymers show not only enhanced degradation abilities typically when exposed to enzymatic activity, but the degradation products are also environmentally friendly materials, such as methane, water, biomass, and carbon dioxide. [12,13] Biodegradable polymers can be divided into two main groups: 1) natural biodegradable polymers that are extracted directly from biomass (polysaccharides, polypeptides, or lipids) or directly from microorganisms, for example, polyhydroxyalcanoates, such as poly(3-hydroxybutyrate) (PHB) and 2) synthetic biodegradable polymers, including a huge variety of aliphatic polyesters such as polylactic acid (PLA) and polycaprolactone (PCL). [14] Specifically, PLA is gaining significant attention due to its strength, stiffness, thermoplasticity, biocompatibility, and good processability.…”