Polyisobutylene Catalog #: 681 Appearance Slab CAS# 9003-27-4 Density 0.93 (23C) Fp (F) >212 Refractive Index (nD) (20) 1.51 Soluble in non-polar organic solvents (i.e. aliphatic, aromatic, cyclic, and halogenated hydrocarbons), THF Tg (C) -64 TSCA TSCA listed Viscosity Average Mw 85,000