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Styrene polymerization inhibition constants

The monomers as well as undent era ted styrene were polymerized in sealed glass tubes, in the absence of catalysts, in a constant temperature bath at 80° C. The mean molecular weight of the obtained polymers was in the range of 1,000,000 except for the jg-deuterio- and the , )8-dideuteriopolystyrenes. In this case the molecular weight was much lower even after a polymerization time of several weeks. The reason for this inhibition lies perhaps in the presence of impurities in the samples from the Grignard or the bromide. The polymers were reprecipitated from methanol and dried overnight in a vacuum oven at 60° C. [Pg.169]

The rate constant for propagation of (polystyrene) Na+ in tetrahydrofinan for 25°C was found to be 400 1-mol s. The rate constants for proton transfer to the anion from water and ethanol were 4000 l-moT s and 4 1-mol sr, respectively. Which of these impurities (water or ethanol) is more likely to inhibit high polymer formation in sodium-catalyzed anionic polymerization of styrene in tetrahydrofuran ... [Pg.218]


See other pages where Styrene polymerization inhibition constants is mentioned: [Pg.199]    [Pg.366]    [Pg.84]    [Pg.164]    [Pg.176]    [Pg.609]    [Pg.267]    [Pg.250]    [Pg.176]    [Pg.151]    [Pg.260]   
See also in sourсe #XX -- [ Pg.265 ]




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