Adhesives specialist Henkel has been working in partnership with researchers from the Leibniz Institute for Catalysis in Rostock (LIKAT Rostock) to develop new bio-based adhesives that can be removed after use, according to a report on the Federal Ministry of Education and Research’s bioökonomie.de website.
As part of the three-year Biovin project, the project partners developed new synthetic building blocks for releasable adhesives based on carbohydrates and vegetable oils, the 16 October report said.
Funded by the German Federal Ministry of Food and Agriculture (BMEL), the Biovin project produced new diols and polyols from bio-based platform chemicals.
LIKAT developed a catalytic synthesis method to convert almost any bio-based polyol or phenol into vinyl ether – monomers used in the production of polymer adhesives, the report said.
“With a yield of up to 98% and a significantly lower formation of undesirable by-products, the process is more selective, efficient and environmentally friendly than the most important commercial technique to date,” the researchers were quoted as saying.
In the project, the new polyols were tested as reactive components in polyurethane adhesives.
In addition, diols and polyols were processed into new, bio-based, multifunctional divinyl ethers (DVE), which were used to produce de-adhesive adhesives.
These new bio-based adhesive compounds were found to adhere particularly well to plastics, but less well to metals.
They also featured lower toxicity, and a more pleasant odour compared to petroleum-based compounds, the research team said.
The new adhesives could also be de-bonded using heat, light or acid, according to the team.
“De-adhesion was achieved under mild test conditions through both thermal and chemical decomposition and was verified by spectroscopic analyses,” the researchers were quoted as saying.
The use of debonding adhesives could make it easier to repair many electronic products or household appliances and make them more recyclable, the report said.
Although improvements were still needed, the newly developed vinyl ether-based polymers had potential for new, recycling-friendly adhesive systems, the researchers wrote.
Prototype tests to create adaptations for a wider range of materials were being conducted by Henkel and if the results were positive, the company said it planned to produce selected vinyl ethers on a commercial scale.
