2,2,4,4-Tetramethyl-1,3-cyclobutane dimethacrylate 2,2,4,4-Tetramethyl-1,3-cyclobutanediyl bismethacrylate 2-Propenoic acid, 2-methyl-, 2,2,4,4-tetramethyl-1,3-cyclobutanediyl ester 52892-98-5 EINECS 258-240-9