A series of novel, well-defined triblock and pentablock terpolymers (Scheme 1) of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiEGVE) were synthesized by sequential base-assisted living cationic polymerization. [1] The living character of the homopolymerization of the three VE monomers and the crossover reaction resulting in the formation of well-defined block copolymers were investigated in various solvents (toluene, dichloromethane and n-hexane) using either a monofunctional [nBVE-acetic acid adduct (nBEA), CEVE-acetic acid adduct (CEEA) and SiDEGVE-acetic acid adduct (SiDEGEA)] or a difunctional [1,4-cyclohexane-1,4-diyl bis(2-methoxyethyl acetate) (cHDMEA)] initiator. All initiators are structurally equivalent to the dormant species of the corresponding monomers in order to achieve fast initiation. The optimal conditions of polymerizations were achieved in n-hexane at -20°C, solvent in which PCEVE is hardly soluble, in the presence of 1 M AcOEt (base). Good control over the number average molecular weight (Mn) and the molecular weight distribution (MWD) were obtained only at [Et3Al2Cl3]0 = [Chain-end]0 ≤ 10 mM. 2,6-di-tert-butylpyridine (DtBP) was used as a non-nucleophilic proton trap to neutralize any protonic initiation from moisture (i.e., Et3Al2Cl3.H2O complex). The thermal properties of the synthesized materials were examined by differential scanning calorimetry. References H. Bouchekif, A. I. Al-Sulami, Y. Gnanou, N. Hadjichristidis Polym. Chem. 2014, submitted.

Triblock and pentablock terpolymers of functionalized vinyl ethers by base-assisted living cationic polymerization

249th National Meeting (2015)

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