2,4,8,10-Tetraoxa-3,9-diphosphaspiro(5.5)undecane, 3,9-diphenyl-, 3,9-dioxide 3,9-Diphenyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro(5.5) undecane, 3,9-dioxide 59609-12-0 71325-79-6 Pentaerythritol spirobis(phenylphosphonate)