Bisphenol Fluorenone Carbonate-Simethyl Siloxane Block Polymers: Transparent, Tough, Heat- and Flame-Resistant Thermoplastics.
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1975
- Accession Number
- ADA017383
Entities
People
- G. E. Niznik
- J. E. Corn
- R. P. Kambour
- Scott T. Miller
Organizations
- General Electric