GB928920A - Nitroacetal compounds - Google Patents

Abstract

Nitro-acetals of general formula <FORM:0928920/IV(a)/1> wherein R and R1 are hydrogen or alkyl radicals, R2 and R3 are hydrogen, alkyl, halogen, nitroalkyl, nitro, aryl, alkylaryl, alkaryl, aralkyl, cycloalkyl, haloalkyl, or nitrazoalkyl radicals, and A is an alkylene radical (see Group IV(b)) are used as plasticizers in the preparation of polyurethane binders for high energy solid rocket propellants, in an amount of up to about 15% by weight.ALSO:The invention comprises nitro-acetals of general formula <FORM:0928920/IV(a)/1> wherein R and R1 represent a hydrogen or an alkyl radical; R2 and R3 a hydrogen, alkyl, halogen, nitroalkyl, nitro, aryl, alkaryl, aralkyl, arylalkyl, cycloalkyl, haloalkyl, or nitrazoalkyl radical; and A is an alkylene radical, and their preparation by reacting a compound <FORM:0928920/IV(a)/2> with a nitro-alcohol of formula <FORM:0928920/IV(a)/3> Aldehydes such as formaldehyde and acetaldehyde may be used and other aldehydes and ketones are listed and they may be prepared in situ, for example by the depolymerisation of paraformaldehyde or paraldehyde in the presence of a catalyst, e.g. sulphuric, hydrochloric, hydrofluoric, p-toluene sulphonic and m-benzene disulphonic acids, zinc chloride, boron trifluoride and boron trifluoride complexes. Nitro alcohols mentioned are 2,2-dinitropropanol, 2-nitrobutanol, 2-chloro-2,4,4,trinitro-1-butanol, 5,5-dinitro-5-phenyl-1-pentanol, 2-nitro- 4-phenyl-2-n-propylphenyl-1- butanol, 3-nitro-3-cyclohexyl-5-bromo-1-pentanol, 7-aza-5,5,7-trinitro-3-octanol, 2,2,2-trinitroethanol, 2,2,4,4-tetra-nitro-n-pentyl, 4-nitraza-2-nitro-, 4-nitraza-2-chloro-, 4-nitraza- 2-phenylmethyln-pentanols, 4-chloro- 2-methyl-2-nitro, 4-chloro- 2,2-dinitro and 4-chloro-2-cyclohexyl- 2-nitro-n-butanols, 2-nitro- 2-p-tolyln-hexanol, 2,5-dinitro-2-ptolyl-n-pentanol, 2-chloro- 2-nitro- 3-phenylpropanol, 3,3-dinitro-3-phenyl-propanol and 3,3-dinitro-1-butanol. The reaction may be performed in an inert solvent such as benzene, toluene chloroform, carbon tetrachloride, methylene chloride and ethylene dichloride, or in an excess of reactant and a catalyst such as the above mentioned or calcium chloride may be used. The products are suitable for use as plasticizers for polyurethanes, nitrocellulose or nitro polymers which may be used as propellants.