Crosslinked poly(methyl methacrylate) with perfluorocyclobutyl aryl ether moiety as crosslinking unit: thermally stable polymer with high glass transition temperature.

Crosslinked poly(methyl methacrylate) (PMMA) with high glass transition temperature ( ) and thermal decomposition temperature was prepared by simple thermal crosslinking of PMMA-containing random copolymers bearing aryl trifluorovinyl ether (TFVE) moieties. A methacrylate monomer consisting of aryl TFVE moiety, 4-((1,2,2-trifluorovinyl)oxy)phenyl methacrylate (TFVOPMA), was first synthesized followed by radical copolymerization with methyl methacrylate (MMA) initiated by AIBN, providing the random copolymer containing aryl TFVE moieties, poly(4-((1,2,2-trifluorovinyl)oxy)phenyl methacrylate)--poly(methyl methacrylate) (PTFVOPMA--PMMA). Finally, crosslinked PMMA polymer with perfluorocyclobutyl (PFCB) aryl ether moieties as crosslinking units was obtained by [2π + 2π] cycloaddition reaction of aryl TFVE moieties in PTFVOPMA--PMMA copolymer. Thermal properties of both PTFVOPMA--PMMA and crosslinked PTFVOPMA--PMMA were examined by TGA and DSC. Compared to pure PMMA, of PTFVOPMA--PMMA increased by 15.1 °C and no was found in the DCS test of the crosslinked PTFVOPMA--PMMA. Thermal decomposition temperature ( ) of crosslinked PMMA was 47 °C higher than that of pure PMMA. Furthermore, the water absorption of crosslinked PMMA film greatly reduced in comparison with that of pure PMMA.