Production of detergent-free PET and biodegradable PBAT micro- and nanoplastics

Microplastics comprise a heterogeneous group of polymer particles that vary in chemical properties, size, and shape, that may influence their environmental and in vivo behavior. Numerous in vitro and in vivo studies show induction of oxidative stress and metabolic disturbances. Valid critique regarding unrealistically high concentrations or additives within standard materials calls some results into question. Here, we present a novel protocol for the detergent-free production of polyethylene terephthalate (PET) and biodegradable poly(butylenadipat-co-terephthalat) (PBAT) micro- and nanoplastic particles (MNPs) as model microplastics for research. The particles were produced by dissolution precipitation from trifluoroacetic acid (TFA) for PET or tetrahydrofuran (THF)/ethanol for PBAT. Different PET sources were investigated for MNPs production. PET MNPs in the size range of 170-1000 nm with up to 80 % yield were produced from pellets as starting material. Particle size can be adjusted by ultrasounding. The non-toxic concentration range for two commonly used detergents was assessed by means of MTT assay. PET particles with a Zeta-potential of -45 were stable in aqueous suspension with and without detergents at neutral pH. Biodegradable PBAT particles in the micro- and nanometer range were produced by adapting the PET precipitation protocol. These high-yield production protocols provide additive-free authentic PET and PBAT MNPs for research.