Of the 30 million tons of plastic produced each year, about two percent end up in the oceans. Eighty percent of this plastic waste enters via rivers and twenty percent is discharged directly into the oceans. The surface of microplastics act like a sponge that also absorbs environmental toxins such as polychlorinated biphenyls (PCBs). Since fish mistake it for plankton and eat it, the microplastic particles enter the human food chain along with the enriched pollutants and eventually end up on our plates . The sources of microplastics in seawater are diverse and come from various applications such as (data are in g/per capita per year: i) abrasion from car tires - 1228.5; ii) waste disposal - 302.8; iii) abrasion from asphalt - 228; iv) plastic granules - 182; v) sports and playgrounds - 131.8; vi) construction sites - 117.1; vii) abrasion from shoe soles - 109; viii) plastic packaging - 99 g; ix) road markings - 91; x) Textile washing - 76.8 .
One approach to reduce the ecological footprint is the use of biodegradable and – where possible – also bio-based plastics in packaging, textile fibers and shoe soles. The EU project Waste2Biocomp focuses on the development of polyhydroxyalkanoates (PHAs) from biomass streams with different and possibly lower degrees of crystallinity. Chemical and biotechnological methods will be used to produce bio-based and biodegradable polyesters for the manufacture of plastics for packaging, textile fibers and nonwovens, and foams for shoe soles and insoles. In all of these applications, abrasion during washing, wearing, or decomposition by weathering can produce PHA microplastics that are biodegradable and do not remain in soil or water for long periods of time.
However, to avoid premature degradation of PHAs and growth of bacteria and fungi, IVW will chemically modify the developed PHAs and use these modifications for nano-encapsulation of the bio-based antimicrobial/antifungal (AM/AF) agents. The nanocapsules produced will be incorporated into packaging materials, textile coatings, and sole/insole foams. The controlled release of AM/AF substances will also provide protection of the consumer against infection during use over a long period of time. Another important step toward circularity is the recycling of plastic waste and the reuse of recyclates in new products. The chemical recycling of PHAs at the end of life will be realized at IVW in the following approaches: i) hydrolysis to monomers/oligomers for further use in PHA synthesis by chemical and/or biotechnological routes and ii) chemolysis to PHA-diols for further use in the development of polyurethane (PU) foams for soles/insoles or other materials. Sustainability (LCA) and toxicity assessments for the developed materials and products will be performed at all stages of development. At the end of the project, three demonstrators will be produced and presented: bio-based films for packaging, textiles/nonwovens for clothing/ face masks, and foams for shoe soles (including sandwich shoe insoles). The project "Waste2BioComp - Conversion of organic waste into sustainable bio-based components" is funded by the Horizon Europe program. Project no.: 101058654.