0
Article Tier 2 Environmental Sources Remediation Sign in to save

Effect of Polymer Properties on the Biodegradation of Polyurethane Microplastics

Environmental Science & Technology 2022 63 citations

AI summary Read the abstract

Researchers investigated biodegradation of different thermoplastic polyurethane formulations in compost, finding that the ester bond chemistry of polyurethanes enables some degree of hydrolytic degradation. The rate and extent of biodegradation varied substantially with polymer chemistry, with ester-based polyurethanes degrading faster than ether-based types.

Polymers

The release of fragments from plastic products, that is, secondary microplastics, is a major concern in the context of the global plastic pollution. Currently available (thermoplastic) polyurethanes [(T)PU] are not biodegradable and therefore should be recycled. However, the ester bond in (T)PUs might be sufficiently hydrolysable to enable at least partial biodegradation of polyurethane particles. Here, we investigated biodegradation in compost of different types of (T)PU to gain insights into their fragmentation and biodegradation mechanisms. The studied (T)PUs varied regarding the chemistry of their polymer backbone (aromatic/aliphatic), hard phase content, cross-linking degree, and presence of a hydrolysis-stabilizing additive. We developed and validated an efficient and non-destructive polymer particle extraction process for partially biodegraded (T)PUs based on ultrasonication and density separation. Our results showed that biodegradation rates and extents decreased with increasing cross-linking density and hard-segment content. We found that the presence of a hydrolysis stabilizer reduced (T)PU fragmentation while not affecting the conversion of (T)PU carbon into CO2. We propose a biodegradation mechanism for (T)PUs that includes both mother particle shrinkage by surface erosion and fragmentation. The presented results help to understand structure-degradation relationships of (T)PUs and support recycling strategies.

More Papers Like This

Article Tier 2

Microbial and Enzymatic Biodegradation of Polyurethane: From Depolymerization to Monomer Valorization

AI summary Read the abstract

A review covered microbial and enzymatic degradation of polyurethane, summarizing the microorganisms and enzymes capable of breaking down this widely used plastic. Identifying effective biodegradation pathways is key to developing biological solutions for polyurethane waste management.

Article Tier 2

Understanding visible light and microbe-driven degradation mechanisms of polyurethane plastics: Pathways, property changes, and product analysis

AI summary Read the abstract

Researchers found that polyurethane plastics break down in water through a combination of microbial action and light exposure, producing secondary microplastics as they degrade. This study reveals a previously underappreciated source of microplastic pollution, since polyurethane is widely used in coatings, foams, and other products that often end up in waterways.

Article Tier 2

Solving the plastic dilemma: the fungal and bacterial biodegradability of polyurethanes

AI summary Read the abstract

This review examined the biodegradability of polyurethane by fungi and bacteria, identifying promising microbial species and enzymes capable of breaking down this widely used but environmentally persistent plastic polymer.

Article Tier 2

Long-term localization experiments reveal aging degradation mechanisms of biobased and petroleum-based polyurethanes in natural environments: degradation characteristics, product assessment and degradation cycle prediction

AI summary Read the abstract

Researchers conducted a 807-day field localisation experiment to study the degradation mechanisms of biobased and petroleum-based polyurethanes used as polymer coatings on controlled-release fertilisers in natural soil environments. The study characterised the degradation products, assessed environmental risk, and developed a predictive model for the degradation cycle, finding that both polyurethane types fragment into microplastic residues at different rates.

Article Tier 2

Review on the Biological Degradation of Polymers in Various Environments

AI summary Read the abstract

This review provides an overview of how biodegradable plastics degrade under different environmental conditions including soil, freshwater, marine, and composting environments. It finds that biodegradability is a material property strongly dependent on environmental conditions, and that many so-called biodegradable plastics degrade far more slowly in nature than in controlled test conditions.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper