Patent GB-1049320-A (GB)
Title: Composite polyether propellants
IPC: C06B45/10
Filed: 1960-03-16
Abstract: A propellant composition comprises an inorganic oxidant and an elastomeric binder, the binder being the reaction product of a polyalkylene ether diol of molecular weight 1500-3000 and a stoichiometric excess of a diisocyanate and cross-linked with a triol of molecular weight 500-3000.  Suitable oxidants are ammonium perchlorate and lithium perchlorate. The diol may be a polyethylene or polypropylene ether diol, a copolymer of tetrahydrofuran and an alkylene oxide, or a blend of polypropylene ether diol with polytetrahydrofuran; the diol should be substantially free from peroxides and carbonyl groups.  Examples of diisocyanates are 2,4- and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate. The triol may be formed by reacting an alkylene oxide with glycerol, trimethylolethane, trimethylolpropane, 1,2,6-hexanetriol, ethanolamine, or propanolamine in the presence of sodium oxide or lithium oxide catalyst.  The propellant composition may also include ferric acetyl acetonate as a polymerization catalyst, di-(2-ethylhexyl) azelate, isodecyl pelargonate, or di-(2-ethylhexyl) sebacate as a plasticizer, phenyl-b -naphthylamine as an antioxidant, the dilauric acid ester of a polyethylene ether glycol as a surface-active agent, and copper, nickel or chromium oxide, lithium fluoride, copper phthalocyanine, or a polyol formed from triethylene glycol and a siloxane as a burning rate modifier. Other optional ingredients are organic boron compounds and pulverized aluminium-magnesium alloy.  The binder may be partly polymerized and the composition then cast into a rocket engine under vacuum and cured in situ.ALSO:A propellant composition comprises an inorganic oxidant and an elastomeric binder, the binder being the reaction product of a polyalkylene ether diol of molecular weight 1500-3000 and a stoichiometric excess of a diisocyanate and cross-linked with a triol of molecular weight 500-3000.  Suitable oxidants are ammonium perchlorate and lithium perchlorate. The diol may be a polyethylene or polypropylene ether diol, a copolymer of tetrahydrofuran and an alkylene oxide, or a blend of polypropylene ether diol with polytetrahydrofuran; the diol should be substantially free from peroxides and carbonyl groups.  Examples of diisocyanates are 2,4- and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate. The triol may be formed by reacting an alkylene oxide with glycerol, trimethylolethane, trimethylolpropane, 1,2,6-hexanetriol, ethanolamine, or propanolamine in the presence of sodium oxide or lithium oxide catalyst. The propellant composition may also include ferric acetyl acetonate as a polymerization catalyst, di(2-ethylhexyl) azelate, isodecyl pelargonate, or di(2-ethylhexyl) sebacate as a plasticizer, phenyl-b -naphthylamine as an antioxidant, the dilauric acid ester of a polyethylene ether glycol as a surface active agent, and copper, nickel or chromium oxide, lithium fluoride, copper phthalocyanine, or a polyol formed from triethylene glycol and a siloxane as a burning rate modifier. Other optional ingredients are organic boron compounds and pulverized aluminium-magnesium alloy.  The binder may be partly polymerized and the composition then cast into a rocket engine under vacuum and cured in situ.