Abstract: The compound m-tetramethylxylene diisocyanate (m-TMXDI), is a domestically, commercially produced aliphatic diisocyanate process produced by a non-phosgenation process for the polyurethane industry with suggested applications in reaction injection molding, surface coatings, and in soft polyurethanes with specialty applications (e.g. as solar cell encapsulants). Applicant's discovery relates to the use of m-TMXDI in an amount from about 0.5 to about 2.0 weight percent for curing a composite rocket propellant composition comprising other ingredients in weight percentages of a high solids loading of aluminum metal fuel (0-20%) and ammonium perchlorate oxidizer (65-88%), hydroxy-terminated polymer binder (7-15%) with antioxidant (0.15 to 1.0% of polymer), plasticizer (0-4%), burn rate catalyst (0.05-6%), and quick cure catalyst system of about 0.02% maleic acid (MA) or maleic anhydride (MAN) and 0.02% triphenyl bismuthine (TPB).

Abstract: This disclosure identifies certain dicarboxylic acids (e.g., maleic and oic) and methods of use to obtain extended pot life in diisocyanate cured polymer systems such as hydroxy terminated polybutadienes, polyesters etc. These compounds also prevent catalysis of the urethane reaction by cure inducing materials such as catocene, iron oxide, ferric floride, etc. without interfering with the function of the cure catalyst triphenylbismuthine.With use of one of these compounds, TPB catalyst can be used even with the more reactive isocyanates. This can be highly desirable since TPB appears to promote the urethane reaction and hence because of this selectivity potentially reduces undesirable side reactions.Typically pot life is changed from 0-2 hours to 12-15 hours.The acids must be preblended with the curing agent 30 minutes to 1 hour for more reactive diisocyanates, and 30 minutes to 3 hours for slow reacting diisocyanates such as IPDI to prevent gassing in the propellant.

Abstract: A method of determining tensile bond strength and lap shear strength betw a liner/insulation material and a propellant composition which is cured to portions of the liner/insulation material.The liner/insulation material is bonded to a propellant composition in a dogbone configuration by positioning a predetermined size of the liner/insulation material in a groove that is constructed in a mold in a transverse direction for a tensile bond strength specimen whereby the propellant is bonded to each side of the exposed liner/insulation material. The lap shear specimen is formed in a mold wherein a predetermined size of the liner/insulation material is longitudinally positioned in a groove that is constructed in a mold.

Abstract: Amine salts which are adducts of an ammonium ion donor selected from ammom perchlorate, ammonium sulfate, ammonium formate, and equal molar mixture of ammonium perchlorate and ammonium formate and cyanoethyl substituted tetraethylene pentamine (TEPAN) or the glycidol reaction product of cyanoethyl substituted tetraethylene pentamine (TEPANOL) are employed as a bonding agent in a solid propellant composition employing a polyester binder of polydiethyleneglycoladipate.Unlike hydroxy-terminated polybutadiene wherein a bonding agent is solubilized and still can function as a bonding agent for inorganic ammonium oxidizer salts in the propellant matrix, polyester binders that solubilize the bonding agent renders the bonding agent ineffectual as a bonding agent. Therefore, with a polyester binder it was found that the bonding agent could not be soluble in the prebinder to be effective in improving mechanical properties.

Abstract: The polyamine compound, TEPAN, a partially cyanoethylated tetraethylene pamine, is reacted with a selected ammonium salt to form an adduct of TEPAN and the selected ammonium salt. The ammonium salt is selected from ammonium perchlorate (AP), ammonium nitrate (AN), ammonium sulfate (AS), and ammonium formate (AF). The process for preparation of the adduct comprises reacting a water solution of the selected ammonium salt with TEPAN while stirring at room temperature. A TEPAN-glycidol derivative product is also reacted with the selected oxidizer salt to form an adduct of the TEPAN-glycidol derivative product.The disclosed adducts (having adduct ratios of 1.0 to 1.8 equivalents of ammonium salt per mole of TEPAN or TEPAN-glycidol derivative product, TEPANOL) improve mechanical properties and processiblity of composite propellant composition containing about 88 weight percent solids (ammonium perchlorate, aluminum, and Fe.sub.2 O.sub.

Abstract: A stoichiometric amount of a polyamine compound selected from the group cisting of cyanoethyl substituted tetraethylene pentamine (TEPAN), or the glycidol reaction product of cyanoethyl substituted tetraethylene pentamine (TEPANOL) is reacted with a stoichiometric amount of perchloric acid to yield an amine salt bonding agent useful in propellant compositions.This improved method prevents the generation of ammonia (as in prior art method) which has to be removed prior to use of amine salt bonding agent in a propellant composition. Also, a lesser amount of diluent water is involved in this method which offers an advantage by not having to strip an excessive amount of water by heat, purge, or vacuum means.The amine salt bonding agents prepared by this improved method are shown to be of like identity and quality as shown by IR spectroscopic examination and their testing in a propellant composition.

Abstract: Maleic anhydride, MAN, as an adjunct to triphenylbismuthine (TPB) yields roved benefits to the mechanical properties of isophorone diisocyanate cured hydroxy terminated polymer binders. Results from several propellant mixes indicate that both pot life and mechanical properties are affected not only by the concentration of TPB catalyst used, but also by the ratio of TPB to MAN. The ratio of TPB to MAN from about 1 to 0.5 to about 1 to 1.5 produces interesting results in the values of stress, strain, and modulus as shown in the data set forth in the specification and as graphically depicted in the drawing. The weight percent of MAN ranges from about 0.0125 percent to about 0.0375 percent, and the weight percent of TPB ranges from about 0.015 percent to about 0.035 percent.