ALIPHATIC-AROMATIC COPOLYCARBONATES DERIVED FROM 2,2,4,4-TETRAMETHYL-1,3-CYCLOBUTANEDIOL

The synthesis of copolycarbonates with high aliphatic contents for pos sible applications as optical plastics is described. Copolymers of 2,2 ,4,4-tetramethyl-1,3-cyclobutanediol (TMCBD) with a series of 14 bisph enol derivatives were prepared and characterized. The refractive index of these materials varies from 1.49 for the 2,2-hexafluoropropane sub stituted copolymer to 1.57 for the 9,9-fluorene substituted copolymer; thus, all of the copolymers exhibit lower refractive indices than the bisphenol A homopolycarbonate. The glass transition temperatures of t he copolymers vary from 110 to 210 degrees C; the beta transition temp eratures vary from -70 to 0 degrees C when measured at 10 Hz by dynami c mechanical analysis. The copolymers exhibited good thermal stability (0-3% weight loss) when heated above the glass transition temperature , and only undergo extensive decomposition (80-90%) at 300-360 degrees C. (C) 1995 John Wiley & Sons, Inc.