Combining isosorbide and lignin-related benzoic acids for high-Tg polymethacrylates

The insertion of rigid aliphatic or aromatic building blocks in polymer structures is an efficient synthetic strategy towards high -Tg polymer materials. In the present work, we have functionalized isosorbide 5-methacrylate with various aromatic lignin-inspired esters to yield a series of isosorbide-2-aryl carboxylate-5-methacrylate mono-mers (ArIMAs) as single regioisomers. The selection of phenyl carboxylate side groups included benzoate, p-cyanobenzoate, meta/para-methoxybenzoates, and different vanillic acid esters. This afforded a range of seven bio-based monomers with different size, polarity, and substitutions. Polymerizations were carried out by con-ventional free radical initiation to obtain the corresponding high molecular-weight poly(aryl carboxylate iso-sorbide methacrylate)s (PArIMAs). The polymerizations were evaluated in different solvents, including toluene, EtOAc, gamma-valerolactone, 2-MeTHF, and DMSO to identify the most suitable conditions. The polymers exhibited high glass transition temperatures in a broad range, from 80 to 168 degrees C, and were thermally stable up to 268 degrees C. Furthermore, dynamic rheology experiments indicated that the polymers were sufficiently stable for melt pro-cessing. The availability of the building blocks combined with the high stability of the polymers make these materials attractive for use as high-performance plastics and coatings.

Automated summary

The insertion of rigid aliphatic or aromatic building blocks in polymer structures is an effective way to synthesize high -Tg polymer materials. In this study, a series of isosorbide-2-aryl carboxylate-5-methacrylate monomers (ArIMAs) were synthesized by functionalizing isosorbide 5-methacrylate with various aromatic lignin-inspired esters. These monomers were polymerized to obtain high molecular-weight poly(aryl carboxylate isosorbide methacrylates) (PArIMAs). The resulting polymers showed high glass transition temperatures and thermal stability, making them suitable for use as high-performance plastics and coatings.