6533b833fe1ef96bd129c057

RESEARCH PRODUCT

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Axel H. E. MüllerLubomír LochmannJiří Trekoval

subject

chemistry.chemical_compoundAnionic addition polymerizationMonomerTetramerChemistryDepolymerizationDimerPolymer chemistryfood and beveragesDisproportionationTrimerDegree of polymerization

description

The decomposition reactions of the lithiated dimer, trimer, and tetramer of methyl methacrylate (MMA) in THF at 25°C were investigated. The decomposition of the lithiated dimer proceeds via depolymerization to lithiated monomer and MMA, addition of MMA to residual lithiated dimer, resulting the trimer (“disproportionation” of the dimer), and subsequent autocondensation of the products. The lithiated trimer almost exclusively undergoes cyclo-autocondensation, whereas for the lithiated tetramer both reactions proceed simultaneously to a remarkable degree. It is shown that the relative rate of autocondensation, which is highly dependent on the degree of polymerization of the oligomer, controls the distribution of products formed. The results indicated that the depolymerization of living PMMA is an important factor even at room temperature, potentially affecting the MWD of the polymers.

https://doi.org/10.1002/macp.1984.021850904