Mechanisms and kinetics of the anionic polymerization of acrylates, 2. Polymerization of tert‐butyl acrylate in a flow tube reactor and effect of lithium chloride and lithium tert‐butoxide

摘要: The kinetics and the molecular weight distributions (MWD) in anionic polymerization of tert-butyl acrylate (tBuA) tetrahydrofuran at 23 ± 3°C were investigated. Tert-butyl α-lithioisobutyrate (tBiB-Li) was used as initiator absence presence additives lithium chloride tert-butoxide (tBuOLi). A flow tube reactor which allowed very rapid mixing reagents, within milliseconds. is extremely fast, half-lives being 0,01 s for system without additive, 0,05 LiCl 3 tBuOLi an additive. rate termination estimated from strong UV absorption enolized β-oxoester end group formed. number-average degree a linear function conversion, absolute values, however, demonstrate efficiencies only ca. 30%. MWD's polymers formed are narrow (Mw/Mn = 1,35 M/Mn 1,08 Mw/Mn 1,77 tBuOLi). After precipitation these values reduced to 1,17; 1,06 1,32, respectively. Experiments stirred tank ampoules lead much broader MWD's. This shows that has effect on MWD substantial importance polymerizations.