DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
SYNTHESIS OF ORGANOMETALLIC POLYMERS
NAVAL APPLIED SCIENCE LAB BROOKLYN N Y
Pagination or Media Count:
In connection with a program to synthesize new siloxane polymers with superior resistance to attack by heat, studies were undertaken to determine the molecular structure of a thermally resistant resinous product obtained from Ph3SiOH and AlCl3, which showed a weight loss of only 9 when heated to 500 C at a rate of 180 Chr. Efforts were also made to obtain information about the reaction mechanism. Results indicate that the material is probably a branched open-chain silicone polymer with attached cyclic siloxane trimer groups. Such materials are more thermally stable than siloxanes with only open-chain or non-cyclic branched molecular configurations. When the polymer is crosslinked through phenyl-silicon bond cleavage and transfer reactions, the thermal resistance is markedly reduced. The course of the catalytic polymer reaction involves a partial scission of the phenyl g oups bonded to the central Si atom, accompanied by a redistribution of groups, to form siloxane polymers of branched structure with attached cyclic trimer units. Exploratory studies were initiated to synthesize open-chain copolymers with SiO and M-O backbone units and branches consisting of Si-O and M-O cyclic rimer groups. Under similar catalysis conditions, Ph3SnOH is disproportionated to give Ph2SnOn and Ph4Sn. Author
APPROVED FOR PUBLIC RELEASE