Accession Number : ADA017383
Title : Bisphenol Fluorenone Carbonate-Simethyl Siloxane Block Polymers: Transparent, Tough, Heat- and Flame-Resistant Thermoplastics.
Descriptive Note : Final rept. 14 Jan 74-13 Jun 75,
Corporate Author : GENERAL ELECTRIC CORPORATE RESEARCH AND DEVELOPMENT SCHENECTADY N Y
Personal Author(s) : Kambour,R. P. ; Corn,J. E. ; Miller,S. ; Niznik,G. E.
Report Date : JUL 1975
Pagination or Media Count : 101
Abstract : Synthesis on the 100g scale of BPF carbonate-dimethyl siloxane block polymers containing minor amounts of silicone has been improved to the point that resins of the desired silicone content and molecular weight can be closely reproduced. A number of simplifying changes have been made in the synthesis procedure during subsequent scale-up. Extrusion and injection molding of these resins into articles of good clarity and mechanical integrity have been mastered. Color varies from light straw to brownish-yellow currently. The two mechanisms of toughening are observed-stress whitening and shear flow; the former is favored by lower silicone contents and complex stress configurations. Flame resistance is paramount among transparent thermoplastics containing no halogen. Limiting oxygen index is 48-51. Char formation is rapid and extensive. No dripping and little smoke are observed. A synergism between the organic and silicone blocks is suggested to be the cause of the superb flame resistance, which is better than in either corresponding homopolymer.
Descriptors : *Silicone plastics, *Block polymers, Injection molding, Synthesis(Chemistry), Manufacturing, Mechanical properties, Flammability, Molecular weight, Casting, Extrusion
Subject Categories : Industrial Chemistry and Chemical Processing
Atomic and Molecular Physics and Spectroscopy
Distribution Statement : APPROVED FOR PUBLIC RELEASE