Accession Number : ADA134286

Title :   Hybrid Fluorosilicones for Aircraft Fuel Tank Sealants. Part 4. Synthesis of Fluorocarbon and Fluorocarbon Ether Hybrid Fluorosilicone Polymers.

Descriptive Note : Final rept. 25 Jan 73-25 Jan 74,


Personal Author(s) : Pierce,Ogden R ; Kim,Yung K ; Riley,Michael O

PDF Url : ADA134286

Report Date : May 1974

Pagination or Media Count : 73

Abstract : Two fluoroether silicone (FES) elastomeric polymers were synthesized, and cured research samples were delivered to AFML for evaluation. These polymers were based on the -(CF2)2O(CF2)NO(CF2)2- (n = 2,5) backbone unit. A one-step synthesis of I(CF2)2O(CF2)2O(CF2)2I from commercially available starting materials was demonstrated: about 110 g of this fluoroether was prepared, and over 500 g of I(CF2)2O(CF2)5O(CF2)2I was synthesized. Coupling studies of the alpha, omega-diiodoperfluoroethers have shown: (1) A good yield (71%) of dimer and trimer is produced by photolysis of I(CF2)2O(CF2)5O(CF2)2I/Hg/C7F16; (2) Fair yields (ca. 40%) of dimer and trimer are produced by heating copper-bronze powder with the ether, but some hydrogen endblocked materials are also produced; (3) Heating with Hg or Cu(Hg) produces mercury-inserted fluoroether oligomers. The following samples of LS/FCS-210 copolymer sealants were prepared and submitted to AFML for evaluation: 1 pound LS/FCS-210 (0.9/1.0), unformulated, 1 pound LS/FCS-210 (0.9/1.0), formulated, Research sample LS/FCS-210 (1-1.2/1.0), unformulated, Research sample LS/FCS-210 (1.5/1.0) unformulated. In addition, Dow Corning Corporation has attempted to prepare samples of alternating LS/FCS-210 copolymers having the following ratios: 1/1, 1.5/1, 2/1. Analyses are pending.

Descriptors :   *Silicone plastics, *Synthesis(Chemistry), *Fluoropolymers, *Sealing compounds, *Fuel tanks, Block polymers, Halocarbon plastics, Heat resistant plastics, Polymers, Silicones, Fluorine compounds, Copolymerization, Curing, Coupling(Interaction), Chemical reactions, Aircraft, Ethers, Elastomers, Physical properties, Ratios, Photolysis, Heating

Subject Categories : Aircraft
      Polymer Chemistry
      Adhesives, Seals and Binders

Distribution Statement : APPROVED FOR PUBLIC RELEASE