Accession Number:

AD0412835

Title:

INVESTIGATION OF POSSIBLE METHODS FOR PREPARING NOVEL SILICON-BASED MONOMERS AND POLYMERS.

Descriptive Note:

Final technical rept., 1 June 62-31 May 63,

Corporate Author:

YARSLEY RESEARCH LAB LTD (GT BRIT)

Personal Author(s):

• Ross,N.C.

Report Date:

1963-06-28

Pagination or Media Count:

1.0

Abstract:

This programme was initiated to synthessee polymers based on a silicon-carbon backbone which possess elastomeric properties combined with thermal stability. A major part of the programme has been devoted to the synthesis of block copolymers of silcarbane and siloxane structurru. Low molecular-weight silcarbane polymers with functional end-groups were synthesised by silicon hydride-silicon vinyl addition reactions, using the monomers 4,4bis dimethylsilyl diphenyl ether and 4,4 bis vinyldimethylsilyl diphenyl ether, and also by the condensation of 1,2 bis chlorodimethylsilyl ethane with the di-Grignard reagent of diphenylether. The end groups of the polymers were hydrolysed to silanol groups and condensation of the silcarbane chains was effected thermally. The block copolymers did not attain molecular weights greatly in excess of 5,000. Polydiphenyleneethersiloxane was synthe sised in high molecular form by the catalytic condensation of 4,4-bis hydroxydimethylsilyl diphenylether. Silcarbane polymers of various structures have been synthesised by reactions oo the silicon-hydride addition type or by the reaction of chlorosilanes with difunctional Grignard reagents. The diphenylene-ether siloxane polymer, -SiCH32 - C6H4OC6H4 SiCH32-O-, showed outstanding stability. Author

Descriptors:

• *ELASTOMERS
• SILICON COMPOUNDS
• POLYMERS
• SYNTHESIS
• STABILITY
• TEMPERATURE
• GRIGNARD REAGENTS
• MOLECULAR WEIGHT
• THERMAL RESISTANCE

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE