Living polymerization of alpha-methylstyrene in tetrahydrofuran followed by dynamic light scattering near its polymerization temperature

We followed the polymerization reaction of living poly-alpha-methylstyrene in a solution of tetrahydrofuran as a function of temperature, near its cei ling temperature, using dynamic light scattering. We obtained three differe nt relaxation times revealing three kinds of macromolecular species in the solution. One of the relaxation times corresponded to the formation of livi ng polymer chains. In this particular case, we found that the average relax ation time increased as temperature was lowered due to polymer growth. Neve rtheless, it did not follow the same track along a cooling-heating cycle. T hese results are consistent with an incomplete depolymerization reaction. F or the other two species, we propose that they were the result of ionic agg regation. (C) 1999 American Institute of Physics. [S0021-9606(99)52722-0].