摘要:
The invention relates to a new class of alkoxy silane compounds of the following general formula: ##STR1## wherein R is aliphatic or aromatic having from 1 to about 15 carbon atoms and R'comprises a hydrolyzable alkoxy functionality. These compounds are particularly useful as adhesion promoters when used with adhesives such as, for example, phenylethynyl terminated polyimide or polysulfide adhesives. The invention also relates to a method of synthesizing the alkoxy silane compounds defined above.
摘要:
The invention relates to a new class of alkoxy silane compounds of the following general formula: wherein R is aliphatic or aromatic having from 1 to about 15 carbon atoms and R' comprises a hydrolyzable alkoxy functionality. These compounds are particularly useful as adhesion promoters when used with adhesives such as, for example, phenylethynyl terminated polyamide or polysufide adhesives. The invention also relates to a method of synthesizing the alkoxy silane compounds defined above.
摘要:
Hexabenzylhexaazaisowurtzitane is converted to tetracetyl, dibenzyl azaisowurtzitane. The benzyl groups are removed by catalytic transfer hydrogenolysis leaving a pair of available nitrogens. The available nitrogens are acetylated, and the resulting intermediate is converted to CL-20 with a strong nitrating agent.
摘要:
A thermoplastic, elastomeric block copolymer comprises at least one poly(butadiene) and at least one pair of poly(lactone) blocks flanking the poly(butadiene) block. Each poly(lactone) block is derived from a lactone having between 8 and 18 carbon atoms in the lactone ring, such as &lgr;-laurolactone and 10-hydroxyl decanoic acid lactone. Alternative methods of making these block polymers are also disclosed. In the first procedure diethyl zinc reacts with the hydroxyl end group of a butadiene polymer to form an intermediate zinc alkoxide-tipped polybutadiene which functions as the active initiating species. The laurolactone polymer then grows off the hydroxyl end groups of the butadiene to form the desired ABA block copolymer. In another related procedure for making ABA block polymers, previously prepared difunctional hydroxyl-terminated polybutadiene blocks are linked with monofunctional poly(&lgr;-laurolactone) blocks using a diisocyanate and a catalyst. The poly(&lgr;-laurolactone) is prepared from &lgr;-laurolactone, diethyl zinc and a suitable mono-functional alcohol. Another procedure describes the direct linking of hydroxyl-terminated poly(butadiene) with a poly(&lgr;-laurolactone) with a difunctional isocyanate producing a polymeric material having an (AB)n structure. Also disclosed are chemically uncured high-energy compositions, such as explosives, gasifiers, and especially solid rocket motor propellants, wherein between about 70-91 wt. % of solid particulates, including fuel material and/or oxidizer, and between about 9-30 wt. % of a binder system comprising a thermoplastic, elastomeric block copolymer system as above described and optionally a plasticizer.
摘要:
A process for synthesizing 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo-[5.5.0.0.sup.5,9 0.sup.3,11 ]-dodecane ("TEX") involves combining at least one hexa-substituted piperazine derivative with a medium containing at least one nitronium anion source and at least one acid sufficiently strong to generate nitronium anions from the nitronium anion source. According to this invention, TEX yield is significantly improved by pre-heating the medium to 55.degree. C. to about 70.degree. C. and maintaining the medium from 55.degree. C. to about 70.degree. C. to permit the hexa-substituted piperazine derivative and nitronium anions to react and form the TEX. At least one NO.sub.x scavenger is added to the medium, preferably before the addition of the hexa-substituted piperazine derivative, to increase TEX yield.
摘要:
Composite propellant formulations are disclosed having a dinitramide salt oxidizer, such as ammonium dinitramide, an energetic binder, such as energetically substituted oxetane and oxirane polymers, a reactive metal, such as aluminum, and other typical propellant ingredients such as curatives and stabilizers. Propellant formulations useful for minimum smoke or reduced smoke applications, preferably include little or no reactive metal. The disclosed propellant formulations are able to combust the reactive metal efficiently, possess high burn rates, and produce little or no HCl exhaust gases.
摘要:
Polymers are produced from 4 and 5 member cyclic ethers, which polymers have hydroxyl functionalities of 4. The cyclic ethers are polymerized with an acid catalyst and a tetraol initiator having the general formula: ##STR1##
摘要:
The present invention provides cyclic nitro compounds, pharmaceutical compositions of cyclic nitro compounds and methods of using cyclic nitro compounds and/or pharmaceutical compositions thereof to treat or prevent diseases or disorders characterized by abnormal cell proliferation, such as cancer, inflammation, cardiovascular disease and autoimmune disease.
摘要:
High solids pressable explosive compositions containing a liquid energetic polymer and a high performance explosive oxidizer are disclosed. The pressable explosive compositions contain a solids content between 91 and 99 weight percent, with an energetic polymer content less than 9 weight percent. The energetic polymer has a weight average molecular weight greater than 10,000, determined using a polystyrene standard, sufficient to use the polymer precipitation technique in preparing the pressable explosive compositions. Chain-extended PGN (polyglycidyl nitrate) is a preferred energetic polymer. The pressable explosives disclosed herein produce extremely high detonation pressure, high detonation velocity, and excellent metal accelerating capability.
摘要:
A method of preparing a thermoplastic elastomer having A blocks and at least one B block, wherein said A blocks are crystalline at temperatures below about 60.degree. C. and said B block is amorphous at temperatures above about -20.degree. C., said A blocks each being polyethers derived from monomers of oxetane and its derivatives and/or tetrahydrofuran and its derivatives, the method comprising:providing monofunctional hydroxyl terminated A blocks which are crystalline at temperatures below about 60.degree. C. and separately providing di-, tri- or tetrafunctional hydroxyl terminated B blocks which are amorphous at temperatures above about -20.degree. C.,end-capping said A blocks by separately reacting said A blocks with a difunctional diisocyanate in which one isocyanate moiety is at least about five times as reactive with the terminal hydroxyl group of the A blocks as the other isocyanate moiety, whereby the more reactive isocyanate moiety tends to react with the terminal hydroxyl group of the A blocks, leaving the less reactive isocyanate moiety free and unreacted, andadding di-, tri- or tetrafunctional B block to the end-capped A blocks at approximately the stoichiometric ratios that they are intended to be present in the thermoplastic elastomer such that the free and unreacted isocyanate moiety on the end-capped A block reacts with a functional moiety of the B block to produce ABA or A.sub.n B thermoplastic elastomers.