(1,1,3,3-Tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl dimethacrylate 1,3-Bis(3-methacryloxypropyl)tetramethyldisiloxane 18547-93-8 2-Propenoic acid, 2-methyl-, (1,1,3,3-tetramethyl-1,3-disiloxanediyl)di-3,1-propanediyl ester EINECS 242-419-3