A facile approach to catechol containing UV dismantlable adhesives

- Photo-labile polymers are synthesized by Passerini multicomponent polymerization.
- These polymers show dual functions, substrate adhesiveness and UV degradation.
- The adhesion performance can be tuned by varying the catechol contents.

We report a facile synthetic approach to a new type of catechol containing UV dimantlable adhesive. A series of linear polymers containing pendent catechol moieties and main chain o-nitrobenzyl ester groups were synthesized by the Passerini multicomponent polymerization (MCP) of a di-o-nitrobenzaldehyde, 1,6-diisocyanohexane, 3-(3,4-dihydroxyphenyl) propionic acid, and undecanoic acid. The content of the catechol moieties was adjusted by varying the molar ratio of 3-(3,4-dihydroxyphenyl) propionic acid to undecanoic acid. The thermal properties of these polymers were investigated, they are stable up to 250 °C, and the glass transition temperatures (Tg) are in the range of 17-70 °C. Increasing the catechol content will increase the Tg and slightly decrease the thermal stability. The pendent catechol groups and the in situ formed o-nitrobenzyl ester linkages in the polymer main chain endow the polymer with dual functions, substrate adhesiveness and UV degradation. The UV degradation process was monitored by 1H NMR, GPC, UV-Vis and FTIR. Lap shear strength tests revealed that the adhesion performance of these polymers could be tuned by varying the catechol contents. UV irradiation could cleave the polymer chains, thus decreasing the adhesion strength.