Selective atom transfer radical polymerization of 1,2,3,6-tetrahydrobenzyl methacrylate (THBMA) and demonstration of thiol–ene addition reaction in the pendant cycloalkenyl functional group

• 1,2,3,6-Tetrahydrobenzyl methacrylate was polymerized via ATRP.
• NMR and MALDI-TOF-MS analyses confirmed the presence of cycloalkenyl functionality.
• Cycloalkenyl group in the polymer was modified via thiol–ene reaction.
• Thiol-modified polymer showed improved mechanical properties.

A tailor-made polymethacrylate bearing reactive pendant cycloalkenyl group was prepared by atom transfer radical polymerization using CuBr as catalyst in combination with N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) ligand. NMR spectroscopy, matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and gel permeation chromatography (GPC) analyses showed the presence of cycloalkenyl functionality and well-defined molecular weight in the prepared polymer. This reactive cycloalkenyl group was modified by thiol–ene chemistry. The thiol–ene modified polymer showed significantly improved adhesion strength, as determined by lap shear test using a UTM. Nanoindentation experiment showed better surface hardness of the UV-cured thiolated polymer.

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