Journal of Applied Polymer Science, Vol.71, No.12, 2039-2048, 1999
Anionic polymerization of secondary aminostyrene and characterization of the polymer
Preparation by anionic living technique and characterization of poly(secondary aminostyrene) having narrow molecular weight distribution were investigated. N-isopropyl-N-trimethylsilyl-4-vinylbenzylamine (SBA) was purified by use of sec-butylmagnesium bromide as a purging reagent under high vacuum. SEA was anionically polymerized with n-butyllithium or cumylpotassium in tetrahydrofuran at -78 degrees C under high vacuum to yield the corresponding polymer (PSBA) in 100% yield. Subsequent deprotection of the trimethylsilyl group from PSBA produced poly(N-isopropyl-4-vinylbenzylamine) (PBA) of the desired molecular weights (M-n: 1.3 x 10(4)-17 x 10(4), determined by membrane osmometry) with narrow molecular weight distribution (M-w/M-n: 1.07-1.03, determined by gel permeation chromatography). The living lithium carbanion of PSBA can initiate styrene (St) to yield PSBA-b-PSt block copolymer (M-n = 4.0 x 10(4), M-w/M-n = 1.05), and the polystyryllithium can initiate SEA to yield PSt-b-PSBA (M-n = 3.7 x 10(4), M-w/M-n = 1.25). The deprotection of the trimethylsilyl group from the two block copolymers produced new block copolymers containing poly(secondary aminostyrene) block. Anionic reactivity of SEA and basic properties of PSBA are discussed in terms of the C-13 chemical shift of beta-carbon in the vinyl group of SEA and steric effect.
Keywords:LIVING POLYMERIZATION;COPOLYMERS