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[摘要]：Styrene/maleic anhydride (S/MA) copolymerizations at initial molar MA feed concentrations integral(MA,0) = 0.10-0.55 were done at 80-110 degrees C in 50 wt % 1,4-dioxane using 5 mol % {tert-butyl-[1-(diethoxyphosphoryl)-2,2-dimethylpropyl]amino}oxidanyl (SG1) relative to -2-({tert-butyl-{1-(diethoxyphosphoryl)-2,2-(dimethylpropyl)amino}oxy)-2-methylpropionic acid (BlocEluilder). As integral(MA,0) increased, the apparent rate constants increased dramatically. Copolymerizations performed with nearly equimolar feeds integral(MA,0) = 0.45-0.55 at 110 degrees C had apparent rate constants similar to 20 times that of styrene at the same temperature. S/MA copolymerizations performed at 110 degrees C with practically equimolar feeds resulted in nearly alternating S/MA/S structures while those performed with integral(MA,0) = 0.1-0.4 possessed little to no S/MA/S alternating structures as indicated by C-13 NMR spectroscopy. However, NMP of S/MA done at 90 degrees C with a styrene-rich feed composition (integral(MA,0) = 0.2) resulted in a poly(S-alt-MA)-block-poly(S) diblock in a single step. C-13 NMR revealed two significant populations of triads corresponding to S/MA/S alternating sequences and to S/S/S homopoly(styrene) sequences. BlocBuilder enabled the polymerization of these one-step block copolymers with a strictly alternating S/MA first block by NMP, thus permitting NMP to join reversible addition-fragmentation transfer polymerization as another controlled radical polymerization method to attain alternating S/MA microstructures. |
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