Thiokol liquid

TABLE II Solubility of Solvents in Thiokol Liquid Polymers"... 

The concentration of the splitting salts regulates the average molecular weight of the liquid polysulfides. For example, Thiokol liquid polymer LP-2 has the following average formula ... 

The results are reported of a study of the disparate swell behaviour in hot water of polysulphide sealants produced with different curing agents (manganese dioxide and ammonium dichromate). Sealants tested were commercial aircraft sealants PR-1750, Pro-Seal 899 and PR-1422 and laboratory formulations prepared using Thiokol liquid... 

R.K. Lund, Encapsulated Liquid Monopro-pellant Ammunition Feasibility Study , Thiokol... 

Prepare a saturated solution of sodium sulphide, preferably from the fused technical sodium polysulphide, and saturate it with sulphiu the sulphiu content should approximate to that of sodium tetrasulphide. To 50 ml. of the saturate sodium tetrasulphide solution contained in a 500 ml. round-bottomed flask provided with a reflux condenser, add 12-5 ml. of ethylene dichloride, followed by 1 g. of magnesium oxide to act as catalyst. Heat the mixture until the ethylene dichloride commences to reflux and remove the flame. An exothermic reaction sets in and small particles of Thiokol are formed at the interface between the tetrasulphide solution and the ethylene chloride these float to the surface, agglomerate, and then sink to the bottom of the flask. Decant the liquid, and wash the solid several times with water. Remove the Thiokol with forceps or tongs and test its rubber-like properties (stretching, etc.). 

A liquid produced by the addition of chlorine to the ethylene double bond. It is reacted with sodium polysulphide to produce polysulphide polymers, trade name Thiokol. 

Thiokol (structure 4.70), which was the first synthetic elastomer, was synthesized by Patrick in the 1920s, by the condensation of alkylene dichlorides and sodium polysulfides. These solvent-resistant elastomers have limited uses because of their foul odor. They can be reduced to liquid polymers that can be reoxidized to solid elastomers, which is used in caulking material and some rocket propellant formulations ... 

Lund, Encapsulated Liquid Monopropellant Ammunition Feasibility Study , Eglin AFB Tech Rept AFATL-TR-61-27 by Thiokol Chemical Corp, Wasatch Division, Brigham City, Utah (1968) 26) R.F. Fletcher, Ann-... 

Chemistry of Polysulfide Polymers. Propellant chemistry based on chemically crosslinked binders had its beginning at the Jet Propulsion Laboratory in the winter of 1946 when potassium and/or ammonium perchlorate were mixed into Thiokol LP-3 polysulfide liquid polymer, to which had been added an oxidative curative, p-quinone dioxime. This polysulfide polymer, as described by Jorczak and Fettes (13), is prepared... 

As there is no certainty that common solid thiokol produced in the form of latex should give a sufficiently homogeneous mass, Thiokol Corporation have worked out a method of starting with liquid thiokol which is then cured . 

As a rule, the liquid thiokol, mixed with an oxidant and an accelerator is poured into a prepared rocket chamber and cured in situ when the charge is solidified. 

According to descriptions published by the Thiokol Chemical Corporation [9] and Gobel [10] liquid thiokol is obtained in the following way ethylene chloro-hydrin is condensed into dichlorodiethylformal (I) which is then treated with sodium polysulphide to form the polymer (II) ... 

The curing of liquid thiokol is based on the reaction of the liquid polymer with lead dioxide or peroxides. Dehydrogenation of the terminal groups of the mercaptan chains of the polymer then takes place followed by elongation of the chains. This reaction may be depicted as ... 

It is characteristic of the technology of the manufacture of rocket charges containing composite propellants with thiokol that the semi-liquid mixture is poured directly into the rocket chamber lined from within with an insulating layer to which the charge adheres tightly ( case-bonded charge). This is a very cheap and rapid method of manufacture. 

Thiokol Chemical Corporation, Trenton 7, New Jersey, Liquid Polymer LP-31 and Liquid Polymers LP-2 and LP-32. 

O) R.C, Kopituk, A New Impact Detonability Tester for Evaluating Materials with Highly Reactive Oxidizers , Reaction Motor Div, Thiokol Chem Corp, Denville, NJ. Paper 1707-61 presented at the American Rocket Society Conference on Propellants, Combustion and Liquid Rockets, Palm Beach, Fla (26-28 April 196l)... 

Thiokol Rubber P G G G G A P G G Applied as the liquid monomer to magnesium powder and cured after incorporation of the other ingredients... 

If a liquid polysulfide (LP) polymer is desired, a chenucal reduction of some ofthe polysulfide groups to thiol terminals is carried out, after which the polymer is cleaned, coagulated, and dried to its final liquid form. The thiol-terminated version is by far the most common form of polysulfide polymers (molecular mass 700-8000 trade name LP Thiokol). A mixture of NaSH and Na2S03 is used to generate terminal SH groups from disulfane structural units (equation 162). 

The properties of polysulphide polymers are summarised in Table 7.2. Cured polysulphide systems possess excellent resistance to most solvents and mild inorganic acids. The solvent resistance depends on the sulphur content of the polymer. Table 7.3 compares the resistance of various liquid polysulphide polymers to a variety of solvents and chemical solutions. However, these data cannot be considered as absolute because the resistance is to some extent dependent on the efficiency of cure. Volume swell values below 40% illustrate excellent resistance. Those between 40% and 90% illustrate fair to good resistance whereas values above 90% may be only fair or even unsatisfactory (Thiokol Chemical Co., 1969). 

Thiokol Chemical Co. (1969) Solvent Resistance of LP Liquid Polysulphide Polymers, bulletin 565 M, May, Thiokol Chemical Corporation, Trenton, NJ. 

A method, using differential scanning calorimetry, has been developed to estimate quantitatively orthorhombic and monoclinic sulfur in sulfur materials. Sulfur cooled from the melt at 120°C immediately gives monoclinic sulfur which reverts to orthorhombic sulfur within 20 hr. Limonene, myrcene, alloocimene, dicyclopentadiene, cyclododeca-1,5,9-triene, cycloocta-1,3-diene, styrene, and the polymeric polysulfides, Thiokol LP-31, -32, and -33 each react with excess sulfur at 140° C to give a mixture of poly sulfides and unreacted sulfur. In some cases substantial amounts of this unreacted sulfur may be held indefinitely in a metastable condition as monoclinic sulfur or S8 liquid. Limonene, myrcene, and dicyclopentadiene are particularly effective in retarding sulfur crystallization. 

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