J. Englert et P. Karges, FLOW-INJECTION ANALYSIS METHOD FOR THE DETERMINATION OF ACTIVE PEROXIDES IN CHLOROPRENE MONOMER, Journal of elastomers and plastics, 26(1), 1994, pp. 11-25
Active chloroprene peroxides have been monitored in polychlorobutadien
e (CR) process by flow injection analysis (FIA). The method measures t
he active chloroprene peroxides which correlate to their effect on pol
ymerization reactivity. It is applicable to samples containing from 0
to 100 ppm peroxide, and is nominally calibrated for 0-15 ppm. The car
rier consists of ferrous thiocyanate dissolved in an acetone/water mix
ture. The organic peroxide oxidizes the ferrous ion to ferric ion whic
h reacts with thiocyanate ion to form a red ferric thiocyanate complex
. The absorbency of the red complex (in the FIB cell) obeys the Lamber
t-Beer law and thus is directly proportional to the peroxide concentra
tion. The analysis cycle is automated to include calibration, analysis
and system flush. This maintains analysis precision and accuracy and
minimizes any problems with plugging due to polymerizable monomer.