The degradation of biodegradable poly(butylene adipate-co-terephthalate) (PBAT) in marine environments presents a significant ecological challenge due to the formation and persistence of microplastics. This study demonstrates that PBAT generates substantially higher quantities of microplastic particles in seawater compared to freshwater, primarily due to accelerated hydrolysis under alkaline conditions. The resulting fragments exhibit distinct morphologies—long, entangled fibers in seawater versus smaller flocculent aggregates in freshwater—indicating that ionic strength and pH strongly influence fragmentation patterns. These microplastics, ranging from 1 to 3 μm in diameter, remain suspended or settle into sediments, where they can interact with microbial communities and aquatic organisms. Notably, despite PBAT’s intended biodegradability, its degradation is markedly slower in cold deep-sea environments, where low temperatures inhibit enzymatic activity and hydrolysis rates. As a result, microplastics may persist for decades, acting as long-term pollutants. Their surface chemistry promotes the adsorption of organic contaminants such as phenanthrene, increasing their potential toxicity.SERCA2 Antibody Protocol Furthermore, ingestion by marine species—including zooplankton and fish larvae—can lead to physical damage, bioaccumulation, and disruption of physiological functions.Cytokeratin 5/6 Antibody web Although PBAT is considered non-toxic in its pristine form, the photooxidation products formed during UV exposure, including carboxylic acids and aldehydes, are toxic and contribute to water pollution. These findings underscore a critical gap: while biodegradable plastics reduce macroplastic waste, they introduce new risks through microplastic release and chemical leaching. Effective environmental risk assessment must therefore extend beyond material composition to include lifecycle behavior in diverse aquatic habitats.
Impact of Polymer Degradation on Microplastic Characteristics and Ecotoxicity
The degradation of PBAT in different aquatic environments leads to profound changes in microplastic characteristics and associated ecotoxicological risks. As the polymer undergoes hydrolysis and photooxidation, it transforms from a continuous film into a heterogeneous mixture of microplastic particles with varying shapes, sizes, and surface chemistries. In seawater, the formation of long, fiber-like microplastics results from selective degradation of amorphous regions, leaving behind crystalline structures that resist further breakdown.PMID:35137437 These fibers, some exceeding 20 mm in length, pose a high risk of entanglement and ingestion by marine life. In contrast, freshwater produces shorter, aggregated floccules that are more prone to sedimentation. Surface analysis reveals the presence of carbonyl groups and hydroxyl functionalities, indicating oxidative modifications that enhance the particle’s ability to bind pollutants. Size-exclusion chromatography confirms molecular weight reduction, while thermogravimetric analysis shows progressive loss of thermal stability. Mechanical testing reveals embrittlement and reduced ductility, particularly after UV exposure, which facilitates fragmentation. Despite PBAT being classified as non-toxic, the degradation byproducts—such as adipic acid, 1,4-butanediol, and low-molecular-weight esters—are environmentally hazardous and may disrupt endocrine systems or impair microbial metabolism. Moreover, studies indicate that PBAT microplastics exhibit sorption capacity for organic pollutants three times greater than PE microplastics, amplifying their role as vectors for contaminant transport. While no acute toxicity was observed in marine zooplankton, sublethal effects such as reduced feeding efficiency and reproductive impairment have been documented in other organisms. These findings highlight that the environmental safety of biodegradable polymers cannot be assumed solely based on their origin; their degradation products and microplastic fate must be rigorously evaluated across diverse ecosystems.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com