Aliphatic expanding agents

Expandable grades of polystyrene are manufactured by steeping volatile polystyrene granules in a low boiling hydrocarbon solvent until the polymer becomes saturated with the solvent. When the granules are put in a mould and are treated with steam, they imdergo an expansion to many times their original volume and the expanded 

Styrene added to polystyrene (%w/w) No phenolic antioxidant addition 0.5% phenolic antioxidant added on polymer No phenolic antioxidant addition 0.5% phenolic antioxidant added on polymer 

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Crosslinked Polystyrene. Polystyrene lightly crosslinked during polymerization by 0.01-0.25% divinylbenzene provides foams, expanded by carbon dioxide or other gases, with greater expandability and resistance to collapse at elevated temperatures (102, 103). Other divinylbenzene copolymers are reported, employing as blowing agent saturated aliphatic or fluoroaliphatic volatile liquids, tetramethylsilane, and azobis-isobutyronitrile (99,106, 108). 

AMMONIO (DICROMATO DI) (Italian) (7789-09-5) Combustible solid. A strong oxidizer. Reacts violently with reducing agents, combustibles, bases, sodium nitrite. Decomposes at about 356°F/180°C, self-sustaining at about 1300°F/704°C heat causes material to expand dramatically with evolution of heat and nitrogen oxides swelling may cause closed container to burst explosively. Solution is acidic. Acids are incompatible with sulfuric acid, caustics, ammonia, aliphatic amines, alkanolamines, amides, organic anhydrides, isocyanates, vinyl acetate, alkylene oxides, epichlorohydrin. Attacks metals in the presence of moisture. 

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