SHOCK REACTION OF HEXANE AT 77, 193, AND 273 K WITH SPECIAL REFERENCETO SHOCK PRESSURE

Shock waves generated by projectile impacts were transmitted into hexa ne and the shocked hexane was analyzed by TCD-GC, FID-GC, GCMS, and FA BMS for produced aliphatic hydrocarbons. The projectile length and its velocity were varied from 10 to 40 mm and from 220 to 1040 m/s; respe ctively. The initial temperature of the hexane was 77, 193 and 273 K. The major products detected throughout the reactions were hydrogen, li ght alkanes from C-1 to C-4, and light alkenes from C-2 to C-3 The min or products were heavy alkanes from C-8 to C-12 and soot-like material s. Experiments with varied projectile length revealed that the shock r eaction occurred only while the shock wave was transmitted through hex ane (about 10(-6) seconds). This short reaction time may be responsibl e for a lower yield of branched products in the shock reaction compare d with yield produced by hexane pyrolysis in previous studies. In the shack reaction of hexane, the dehydrogenation was one of the important reactions and the recombination of hexyl radicals might play a role i n the formation of n-C-12. Experiments with varied initial temperature suggested that the molar yield of products depends not on the shock t emperature but on the shock pressure, and that the reaction mechanisms for solid hexane and for liquid hexane are not identical. As the shoc k pressure increased, the relative yield of heavy products increased w hile that of light products decreased. This could be interpreted mainl y by considering the activation volumes of the reaction involved.