Thiokols

Polysulphide rubbers. Ethylene dichloride and excess of sodium tetrasulphide when heated together give a polymeric polysulphide, Thiokol A, with properties resembling those of rubber ... 

PP -dichloroethyl ether 0(CH2CH2C1)2 (Thiokol B), and glycerol ay-dichlorohydrin C1CH2CH(0H) CH2CI (Vulcaplas). 

Prepare a saturated solution of sodium sulphide, preferably from the fused technical sodium polysulphide, and saturate it with sulphur the sulphur content should approximate to that of sodium tetrasulphide. To 50 ml. of the saturated 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 hquid, and wash the sohd several times with water. Remove the Thiokol with forceps or tongs and test its rubber-like properties (stretching, etc.). 

TTiokol A [14807-96-6] TTiokol FA [68611-48-3] Thiokol solid rubbers TTiokol ST [9065-29-6] Thiol... 

R. A. McKay,M Study of Selected Parameters in S olid Propellant Processing,]et Propulsion Lab, Pasadena, Calif., Aug. 1986 J. L. Brown and co-workers. Manufacturing Technologyfor SolidPropellantIngredients/Preparation Reclamation, Morton Thiokol, Inc., Brigham City, Utah, Apt. 1985 W. P. Sampson, Eow Cost Continuous Processing of Solid Rocket Propellant, Al-TR-90-008, Astronautics Laboiatoiy/TSTR, Edwards AEB, Oct. 1990. 

J. L. Blown and co-workeis. Manufacturing Technologyfor SolidPropellant Ingredients/Preparation Reclamation, Moiton Thiokol, Inc., Brigham City, Utah,... 

Magnesium hydroxide is white, has an average particle size of 1—10 p.m, density of 2.36 g/mL, refractive index of 1.58, and Mohs hardness of 2.00. Water loss on ignition is 31.8 wt %. Magnesium hydroxide contains 1.0 wt % Ca(OH)2 and is made by Solem Industries and Morton Thiokol (25). 

During the 1930s gradual improvements in the product and processing overcame some of the drawbacks of this material. Nonetheless, the apphcations were limited and Thiokol Corp. stmggled to remain solvent. The first year Thiokol reported a profit was in 1941, 13 years after its foundation. This was realized when the U.S. Air Force discovered that the aUphatic polysulftdes were usehil as a fuel-resistant sealant for aircraft tanks and hoses. Polysulftdes also began to be used as sealants for boat hulls and decks. 

Some of the early Thiokol soHd mbbers are stiU made and used in printing roUs, solvent-resistant spray hose, gaskets, and gas-meter diaphragms. Many of the polysulfide products have been in use since the 1940s with an exceUent track record. Continuing improvements in technology keep these products competitive. 

The commercial polysulfldes are made from bis-chloroethylformal (formal) as shown later in equation 11. In some products trichloropropane is added as a branching agent. Table 1 shows typical properties of polysulfldes available from Morton International. These products were acquired from Thiokol Corp. in 1983. 

The solid polysulfide products are light brown mill able mbbers. Thiokol ST [9065-29-6] (2) is made as in equation 11 with 2% branching agent added. Its... 

Water Dispersions. Polysulftde products are offered as aqueous dispersions (Thiokol WD-6). These are useful for applyiag protective coatings to line fuel tanks, and for concrete, wood, and ia some cases fabrics, felt, leather (qv), and paper (qv). It has been found that a stable emulsion can be made that contains both LP and manganese oxide curing agent. The emulsion can be thinned and appHed as a spray coating. After it is appHed, water evaporates and the LP cures to form a soHd mbber (13). 

Rubber Articles. The soHd polysulftde mbber products, Thiokol FA and Thiokol ST, are used ia the manufacture of printing roUers, printing blankets, gas meter diaphragms, O-rings, and specialty molded items. 

Polysul des. Polysulfides are also called Thiokol s (T) after the company that originally made them. They were discovered in 1927 (see... 

Thiokol elastomers possess fairly low tensile and tear properties. However, they have exceUent resistance to both aHphatic and aromatic solvents at room temperature and slightly elevated temperatures. The Thiokol division of Morton International Corporation is the suppHer of polysulftde elastomers in the United States. It is estimated that 1360—1600 t are used aimually in the United States. The primary use of polysulftde is in seals, gaskets, roUs, and diaphragms where solvent resistance and low permeabiHty are useful. 

ThaUous sulfate, thaUous nitrate, and thaUous and thaUic oxide are the main compounds produced in bulk quantities by Noah Chemical. Approximately 20 other thallium compounds are also available commercially from Noah Chemical, Cooper Chemical, and Alfa Products, Ventron Division, Thiokol Corporation, in research and production quantities. However, demand for thallium compounds is small and limited to such appHcations as synthetic or analytical reagents. 

---