Sticky residue is an issue for the recycling industry since it results in low-quality goods, clogged water systems, and even damaged recycling equipment.
Though now degradable polymers developed by researchers at the University of Surrey have made it possible to dissolve adhesive residue that has been left on recyclable materials like glass and cardboard.
Adhesives are composed of a web of polymer molecules that resemble chains that have been permanently joined together, which is what causes the residue buildup on recycled materials like glass and cardboard. On an industrial scale, network residues are a vexing issue, and the effects of insoluble adhesives on the quality of recycled products are even more worrisome. With our approach, recycling will be less difficult and more affordable.
The recently developed adhesive contains the chemical additive thionolactone, which accounts for 0.25% of its composition. The additive offers a novel way to make recycling processes residue-free by forming what we refer to as degradable thioester linkages in the polymer network. Due to this addition, it is now possible to dissolve the adhesive during the recycling process, which was not previously conceivable. It is quite similar to the adhesive found in conventional packaging tape. In comparison to a non-degradable adhesive, labels can be removed up to 10 times faster.
As stated by the developing teams, there are other degradable adhesives, but none of them are chemically similar to the ones that are currently in widespread use. The discovery is demonstrating the viability of using comparable adhesives and demonstrates the possibility of a straightforward addition to improving the quality of recycled materials like glass and cardboard.
Up until now, the adhesive has undergone testing on various surfaces, including glass, steel, plastic, paper, and even cardboard. The following procedures would be to assess the additive’s commercial viability and sustainability impact.
University of Surrey. 2023. PyhsOrg; Solving industry’s sticky recycling issues. Retrieved from https://phys.org/news/2023-07-industry-sticky-recycling-issues.html#google_vignette
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