Anionic polymerizations of ZV.N-dimethyl-4-vinylbenzenesulfonamide (6a), sulfonyl]piperazine (6c) were carried out at -78 °C in tetrahydrofuran. The initiators included potassium naphthalenide, oligo(a-methylstyryl)dilithium, -disodium, and -dipotassium, (1,1,4,4-tetraphenylbutanediyl)dilithium and -dipotassium, [1,1-bis-[(4,-(trimethylsilyl)phenyl]hexyl]lithium,and [l,l,4,4-tetrakis[4,-(trimethylsilyl)phenyl]butanediyl]dipotassium. These polymerizations gave poly(6)s in quantitative yields. In all cases, the obtained polymers had narrow molecular weight distributions lMjMn < 1.15) and molecular weights predicted from the molar ratio of monomer to initiator, indicating that the anionic polymerizations of these monomers gave stable living polymers. Novel block copolymers, poly(6b-6-styrene-6-6b), poly(6b-6-isoprene-6-6b), poly(6b-b-2-vinylpyridine-6-6b), poly(2-vinylpyridine-6-6b-6-2-vinylpyridine), poly(methyl methacrylate-b-6b-6-methyl methacrylate), poly(terí-butyl methacrylate-6-6b-6-iert-butyl methacrylate), and poly(6c-6-styrene-b-6c) were synthesized using these living systems.
Anionic polymerizations of ZV.N-dimethyl-4-vinylbenzenesulfonamide (6a), sulfonyl]piperazine (6c) were carried out at -78 °C in tetrahydrofuran. The initiators included potassium naphthalenide, oligo(a-methylstyryl)dilithium, -disodium, and -dipotassium, (1,1,4,4-tetraphenylbutanediyl)dilithium and -dipotassium, [1,1-bis-[(4,-(trimethylsilyl)phenyl]hexyl]lithium,and [l,l,4,4-tetrakis[4,-(trimethylsilyl)phenyl]butanediyl]dipotassium. These polymerizations gave poly(6)s in quantitative yields. In all cases, the obtained polymers had narrow molecular weight distributions lMjMn < 1.15) and molecular weights predicted from the molar ratio of monomer to initiator, indicating that the anionic polymerizations of these monomers gave stable living polymers. Novel block copolymers, poly(6b-6-styrene-6-6b), poly(6b-6-isoprene-6-6b), poly(6b-b-2-vinylpyridine-6-6b), poly(2-vinylpyridine-6-6b-6-2-vinylpyridine), poly(methyl methacrylate-b-6b-6-methyl methacrylate), poly(terí-butyl methacrylate-6-6b-6-iert-butyl methacrylate), and poly(6c-6-styrene-b-6c) were synthesized using these living systems.
“…The solubility of poly(l) resembles that of polystyrene, as previously reported. 2 The poly(l) can be cast from its THF solution to give a transparent, colorless, and brittle film. .ß'…”
“…21 Solubilities and Glass-Transition Temperatures of the Polymers. The solubilities of the resulting polymers are summarized in Table 4 with those of poly-(4-vinylbenzoic acid) [10][11][12] and polystyrene as the references. Poly(1) and -(2) were soluble in a variety of organic solvents and showed good solubility similar to polystyrene except for in Et 2 O.…”
Section: Methodsmentioning
confidence: 99%
“…We also successfully demonstrated the synthesis of well-defined poly(4-vinylbenzoic acid) containing an aromatic COOH group in each monomer unit by using the above methodology. For this purpose, three protected monomers, tert -butyl 4-vinylbenzoate, N -(4-vinylbenzoyl)- N ‘ -methylpiperazine, and 2-(4-vinylphenyl)-4,4-dimethyl-2-oxazoline, (Chart ) were employed to protect the COOH function of 4-vinylbenzoic acid. In these polymerizations, we have observed that the nucleophilicity of the resulting living polymers is significantly lowered by the electron-withdrawing effect of three substituents through the extended π -conjugation systems. , 1 …”
Anionic polymerizations of four styrenes protected with bicyclic ortho ester moieties, 1-(4-vinylphenyl)methyl-4-methyl-2,6,7-trioxabicyclo[2.2.2]octane (1), 1-[2-(4-vinylphenyl)ethyl]-4-methyl-2,6,7-trioxabicyclo[2.2.2]octane (2), 1-(3-vinylphenyl)-4-methyl-2,6,7-trioxabicyclo[2.2.2]octane (3), and 1-(4-vinylphenyl)-4-methyl-2,6,7-trioxabicyclo[2.2.2]octane (4), were carried out in THF at -78°C for 0.5 h with oligo(R-methylstyryl)lithium and -dipotassium and potassium naphthalenide. Poly(1)-(3) were quantitatively obtained, and the resulting polymers possessed the predicted molecular weights based on the molar ratios of monomers to initiators and narrow molecular weight distributions (MWDs, M w/Mn < 1.1). By contrast, polymerization of 4 did not go to completion and gave insoluble polymeric product in low yield due to the side reactions under the similar conditions. The substituent position in the monomer was very important for the success of the polymerization, although the bicyclic ortho ester was found to be stable under the polymerization conditions of 1-3. Well-defined block copolymers of 1 and 2 with styrene were synthesized by the sequential block copolymerizations regardless of the order of addition of the monomers. Hydrolyses of bicyclic ortho ester moieties of the resulting polymers were performed at room temperature by treating with 6 N HCl in THF/MeOH for 1 h and subsequently with 10% NaOH-(aq) in THF/MeOH for 12 h. Deprotections of poly(1), poly(2), and poly(3) quantitatively proceeded to afford poly [(4-vinylphenyl)acetic acid], poly [3-(4-vinylphenyl)propionic acid], and poly(3-vinylbenzoic acid) having tailored chain structures, respectively.
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