Keele Research Repository

The interaction of styrene with HCl04 has been studied in
CCl4, CHCl3, CH2Cl2, EtN02 and PhN02.
No polymerisation occurs in CCl4 at 0 degrees.
The polymerisation in CHCl3 at 0 degrees, -30 degrees and -60 degrees is complicated by side reactions of the acid with the solvent. At 0 degrees and low acid concentrations, however, the reaction is of first-order with respect to monomer.
The polymerisation in CH2Cl2 at 0 degrees appears to follow first-order kinetics up to about the first half-life of the reaction, after which the reaction rate increases continuously. Attempts have been made to determine the nature of the propagating species. To this end, the polymerisation in CH2Cl2 has also been carried out in the presence of ethanol and triethylamine, and in the presence of an electric field. The effect of the "scavengers" on the polymerisation depends on the sequence of addition of the reagents involved. The electric field increases the reaction rate continuously.
The polymerisations in EtN02, and PhN02, at 0 degrees are complicated by side reactions of the acid with the solvent.
The interaction of styrene with CF3SO3H in CH2Cl2 has been carried out at 0 degrees, -30 degrees, -60 degrees and -90 degrees. The acid, when mixed with CH2Cl2 alone, reacts with the solvent and something in the glass forming at least two products. The rates of the polymerisation increased with the age of the acid solutions.
An improved extraction method has been developed to
prepare anhydrous HClO4/CH2Cl2 solutions safely.