New reactions and cross-linking in water / photoactivation

Can you imagine a molecule that is running through your veins being a building block for a coating or paint? This molecule is called lipoic acid or thioctic acid. Lipoic acid is a potent antioxidant, and as such it is being sold in the pharmacies. From the chemical point of view, it is also an interesting molecule as it has a polymerization site that can be used to obtain dynamic materials. The materials obtained with the use of this site can be depolymerized with the use of many triggers (acid, base, light, heat). This molecule however has also another interesting site that can be modified to introduce new chemical functionalities. In my project we did both:

(1) we used the site suitable for modification to anchor the molecule to the polymer and then we used UV light to crosslink that polymer. We also proved that we can reverse the crosslinking process, and recycle the functionalized polymer

(2) we functionalized thioctic acid to obtain derivatives that could enhance material properties. Thanks to that dual monomers have been obtained which polymerized by UV-light in bulk (without any additives) were able to form robust coatings.

Overall, in this project, we used the derivatives of a molecule existing in nature, as well as we developed methods of crosslinking that required only the use of light (and photoinitiator in some of the cases to speed up the curing process).