Cellulose esters storage

The advanced applications for nitrocellulose plastisol propellants require that they be integrally bonded to the motor case. Successful case bonding for the multiyear storage life of a rocket calls for special adhesives and liners which are completely compatible with these highly plasticized propellants. Best results have been obtained with a combination of an impervious rubber liner and a crosslinked adhesive system with a limited affinity for the plasticizers used in the propellants. Examples of effective liners are silica-filled butyl rubber and chlorinated synthetic rubber. Epoxy polyamides, isocyanate-crosslinked cellulose esters, and combinations of crosslinked phenol-formaldehyde and polyvinyl formal varnishes have proved to be effective adhesives between propellant and impervious liners. Pressure curing of the propellants helps... 

Polyesters from propylene glycol and dicarboxylic acids, especially adipic and sebacic acid, are commercial products suggested for PVC as well as for cellulose esters. The well known Paraplex resins of Rohm Haas, which are compatible with nitrile and GRS rubber, belong to this group. Other products are the Ultramolls of Farbenfabriken Bayer. Some polyesters of this type have a tendency to exude on storage, especially if esterification is not complete. 

Table III. Moisture Regain of Cellulose Esters upon Storage ...

NFPA Health 1, Flammability 3, Reactivity 0 Storage Store in tightly closed containers in cool, well-ventilated area separate from work place limit quantities in use Uses Solvent for natural and syn. resins, cellulose esters and ethers, paints, printing inks, waxes, veg. oils, pharmaceuticals organic synthesis chemical intermediate in polishes brake fluids degreasing solvent antiseptic antifoam, solvent in cosmetics synthetic flavoring agent in foods and pharmaceuticals in food-pkg. adhesives in cellophane for food pkg. 

Hazardous Decomp. Prods. Heated to decomp., emits toxic fumes of NOx NFPA Health 3, Flammability 2, Reactivity 0 Storage Store in a cool, dry, well-ventilated area, out of direct sunlight limit quantities in storage Uses Anticorrosion agent for ferrous metals solvent for oils, resins, some cellulose esters raw material for vulcanization accelerators, lubricant additives, antioxidants flotation reagents dyestuffs... 

Aluminium alloys have an excellent resistance to the action of reagents used for the fabrication of cellulose acetate acetic anhydride, concentrated acetic acid, butyric anhydride, and cotton. Many pieces of equipment in various aluminium alloys are used in production units for cellulose esters 3003, 5052, A-S13 (44100), etc., for storage tanks, reaction vessels, dryers, evaporators, and valves. 

The first examples of thickened cyanoacrylate adhesives were described by Coover and Shearer in a U.S. Patent. The thickeners cited and claimed were polyalkyl cyanoacrylates, polyacrylates, polymethacrylates, cellulose nitrate, and cellulose organic acid esters, such as cellulose acetate butyrate. Several years later. Wicker and Shearer improved the process for thickening cyanoacrylates. Instead of adding the thickener directly to the monomer, the thickener was first dissolved in a volatile solvent and then added to the ester. The solvent was then vacuum stripped to give the thickened adhesive. The authors claimed that this process gave adhesives having better clarity, better storage stability, and faster cure speed than adhesives prepared by the older method. 

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