Heat-Resistant Poly(methyl methacrylate) by Modification with Perfluorocyclobutyl Methacrylamide Monomers

Abstract

Poly(methyl methacrylate) (PMMA) is widely studied for its attractive properties, including good processability, excellent optical characteristics and low cost. Nevertheless, a persistent challenge for PMMA-based materials is their limited thermal stability. Herein, a series of PMMA copolymers containing perfluorocyclobutyl (PFCB) aryl ether groups were prepared to enhance the heat resistance of PMMA-based materials via the introduction of rigid PFCB aryl ether moieties and the formation of a cross-linked network. PFCBMA, a methacrylamide monomer consisting of PFCB aryl ether moiety, was firstly synthesized and copolymerized with MMA to give PFCB-containing PMMA copolymers (PPFCBMA-co-PMMA), which exhibit higher glass transition (Tg) and thermal decomposition (Td) temperature than PMMA. Subsequently, a dimethacrylamide monomer bearing PFCB aryl ether moiety (MAPFCBMA) was synthesized and copolymerized with MMA to afford crosslinked PMMA copolymers (Cross-PFCB-PMMA) with PFCB units serving as crosslinking points. These Cross-PFCB-PMMA polymers show much higher thermal decomposition temperatures than pure PMMA and PPFCBMA-PMMA. Furthermore, no glass transition was observed below 250°C in DSC analysis of Cross-PFCB-PMMA polymers. This work demonstrates that incorporating PFCB aryl ether moieties, introducing amide bonds and constructing a crosslinked network are effective strategies for improving the thermal stability of PMMA-based polymers.