6533b861fe1ef96bd12c421e
RESEARCH PRODUCT
false
G. V. SchulzN. CardonaM. Chmelirsubject
chemistry.chemical_compoundMonomerChain-growth polymerizationBulk polymerizationPolymerizationChemistryPolymer chemistryPrecipitation polymerizationSolution polymerizationChain transferIonic polymerizationPhotochemistrydescription
The solution polymerization of styrene in methylene dichloride catalysed by trifluoromethanesulfonic acid takes place at a high rate even at low catalyst concentration. The S-shaped course of the conversion curves is explained by a reaction mechanism, in which the catalyst rapidly forms an inactive complex with one monomer molecule, and this monomer-acid complex is in equilibrium with the free catalyst molecule from which the propagating species are formed. Therefore, the formation of active initiating species becomes a slow process which depends also on the change of monomer concentration during polymerization. It is assumed that the active initiating species are formed from two or three molecules of acid and this process is supposed to be a determining step in the mechanism of the styrene polymerization. The conductivity of the polymerizing system is caused probably by at least two species: firstly by the 1-aralkyl-3-phenylindanyl cation which was found by means of UV spectroscopy and which is formed during and after the polymerization as product of termination reaction; secondly by another species, which takes part, as we assume, in the propagating process, probably as polystyryl carbcation.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1977-01-01 | Die Makromolekulare Chemie |