In the latest app-exclusive article, ILM Consultant Technical Editor Karl Flowers explores the dangers of microplastics, an issue so ubiquitous that the leather industry is also part of the problem.

Most leather is biodegradable and, therefore, industrial composting could be a sustainable method for leather disposal in the future. Although most leathers do biodegrade, samples that are finished with polymeric finishing agents often leave the finish residue behind during biodegradability laboratory tests.

The heavy crosslinking in these finishes make them very resistant to degradation. Over time, chemical and physical methods are likely to fragment these polymers into smaller pieces (i.e. microplastics).

Chemical degradation includes oxidation (such as photooxidation and thermolysis) and acid or alkaline-mediated hydrolysis, whereas physical degradation involves changes in the polymer structure.

Plastic degradation is generally onset by oxidation, which then results in mechanical destruction as the polymer becomes brittle and fragments into smaller pieces. In a composting environment, these microplastics can contaminate the resulting compost and subsequently the soils where the compost may be applied.