Hybrid Fluorosilicones for Aircraft Fuel Tank Sealants. Synthesis of Fluorocarbon and Fluorocarbon Ether Hybrid Fluorosilicone Polymers

摘要

The objective of the exploratory development was the synthesis and evaluation of hybrid fluorosilicone sealants for possible use as integral fuel tank sealants and other applications in high performance aircraft. The synthesis of alpha,omega-difunctional fluorocarbon ethers was accomplished from both BrCF2CF2COF and FOC(CF2)3COF in which the functional groups were either bromine or iodine. An additional starting material, FOC CF2OCF2COF was successfully prepared starting with 1,4-hexachlorobutadiene. It was found that these functional fluorocarbon ethers could be coupled to form short polymer chains using mercury. A hybrid fluorosilicone-fluoroether (FES) sealant was prepared containing the ether unit, -CF1CF2O(CF2)2,3- in the polymer backbone. (Author)