CIRCADH II Development of advanced and sustainable polyurethane adhesives
Reactive hot-melt polyurethane adhesives are becoming increasingly popular in the footwear industry due to their advantages over conventional adhesives. However, their low initial adhesion and the toxicity caused by the presence of residual isocyanate monomer are slowing down the expansion of this type of adhesive in the sector. Furthermore, the industry is looking for reversible adhesives that make it easier to separate components, as well as to reuse or recycle them, in order to address the environmental and regulatory challenges posed by the management of discarded footwear waste. For this reason, INESCOP, within the framework of the CIRCADH II project funded by IVACE, seeks to develop adhesives that are more environmentally sustainable, with greater initial adhesion, and that lose their adhesive properties after their useful life in order to facilitate recycling.
During the first year of the CIRCADH project, a protocol was established to implement ecodesign in footwear and adhesive companies based on the life cycle analysis of products. The research carried out by INESCOP enabled the introduction of bio-based raw materials into polyurethane adhesive formulations. The aim is to implement these results in this second year of the project to help the industry reduce its carbon footprint.
On the one hand, footwear and adhesive companies require more sustainable formulations that eliminate the presence of residual isocyanate monomers in order to comply with European legislation on the safe use of isocyanates. On the other hand, the sector needs innovative solutions to reduce the toxicity of these products and improve their environmental and occupational safety. Improving initial adhesion will also make these adhesives competitive compared to those currently used in the industry.
Adhesion on demand through the incorporation of reversible bonds in formulations is another key advance sought by the project, that could help closing the loop of the circular economy.
In this context, INESCOP, with funding from IVACE, is developing the CIRCADH II project to provide reactive hot-melt polyurethane adhesives with advanced and sustainable properties.
CIRCADH II OBJECTIVE
The overall objective of CIRCADH II is to obtain environmentally sustainable polyurethane adhesives that also help to meet the new legislative requirements regarding the toxicity of isocyanates and waste management in the footwear industry.
EXPECTED RESULTS
CIRCADH II aims to develop a methodology for the formulation of polyurethane adhesives by incorporating additives and optimising reaction conditions to produce adhesives based on sustainable raw materials. These adhesives must also exhibit initial adhesion and contain less than 0.1% residual isocyanate monomer. In addition, reversible polyurethane adhesives based on Diels–Alder chemistry will be developed, capable of reducing adhesive strength by at least 50% at the end of the product’s life cycle.
Start date: 01/01/2024
End date: 31/12/2024
Reference: IMDEEA/2024/43
Digital leaflet Results report and Dissemination report (deliverables)
Collaborating companies:
The CIRCADH II project contributes to the following SDGs:
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