o-Terphenyl is used as a plasticizer for polystyrene for thermoplastic recording. Terphenyl mixtures are used industrially as heat storage and transfer agents, as textile dye carriers, and as intermediates in the production of nonspreading lubricants. From 1960-1970, technical grade terphenyls were used as coolants for nuclear reactors, whereas contemporary use has been in solar-heating systems.
Colorless or light-yellow solid. Mp 58-59°C; bp: 337°C. Density: 1.16 g cm-3. Insoluble in water. Usually shipped as a solid mixture with its isomers m-terphenyl and p-terphenyl that is used as a heat-transfer fluid.
O-TERPHENYL is non-flammable but combustible (flash point 339°F). Extremely stable thermally. Incompatible with strong oxidizing agents but not very reactive at room conditions.
Combustible. Eye and upper respiratory
tract irritant.
Moderately toxic by ingestion. Combustible when exposed to heat or flame. To fight fire, use water, CO2, dry chemical. When heated to decomposition it emits acrid smoke and irritating fumes.
Crystallise o-terphenyl from EtOH. Also purify it by chromatography of CCl4 solution on alumina, with pet ether as eluent, followed by crystallisation from pet ether (b 40-60o) or pet ether/*C6H6. It also distils under vacuum. [Beilstein 5 III 2292, 5 IV 2478.]
