A different kind of polymer adhesive
I have already written about the topic of adhesives here a few times. It’s a very interesting topic, and there are always amazing new things to report. This time too.
An adhesive that does not bond materials by mechanical forces (adsorption), as is usually the case, but rather an adhesive that simply cheats its way between a carbon-hydrogen bond and thus holds polymers that are otherwise difficult or impossible to bond together permanently by chemical means.
How does it work?
A Canadian company has developed an adhesive based on bis-diazirines, of which we already know from other sources how reactive these three-ring systems are.
The bis-diazirines each contain a heterocyclic three-ring at two ends, consisting of carbon and a double-bonded nitrogen. When this molecule, which is stable at room temperature, is exposed to moderate heat, UV light or electrical energy, these three rings break open and the resulting highly reactive carbenes (rather unstable compounds of divalent carbon with a free, reactive pair of electrons) push themselves between a C-H, N-H or O-H bond.
If there are 2 diazirines in the molecule, the molecule acts as a crosslinker and can bond 2 polymer chains together. These molecules can thus chemically bond polymers such as polyethylene or polypropylene, which are otherwise difficult to bond together, covalently.
This superglue has already been successfully tested on polyethylene, polypropylene, polystyrene, polycaprolactone, acrylates, polyurethanes, aramid, but also on polymers with glass, ceramics, wood, paper, textiles, etc.
It has been shown that even elastomers and moist surfaces can be bonded, opening up interesting possibilities for new medical and dental applications, for example.
This adhesive can also be applied to polymer textiles to bond and reinforce fibers. This means that fabrics made of ultra-high molecular weight polyethylene can also be used for ballistic protective equipment and wind sports applications.
We will certainly be hearing a lot more about this very innovative small Canadian specialty chemicals company “XlynX Materials Inc.” in the future – it remains exciting. SVP will keep you informed.
Dr. Ronald Hinz, Market Intelligence Senior Expert
Sources:
- XlynX Materials, Kleb- und Dichttechnik, Chemical Science; doi.org/10.1039/D0SC06283A, 2021
