The Copolymerization of the Vinyl Monomer with a Cyclic Compound. III. The Cationic Copolymerization of Styrene with Substituted Ethylene Oxides
01 Apr 1966-Bulletin of the Chemical Society of Japan (The Chemical Society of Japan 公益社団法人 日本化学会)-Vol. 39, Iss: 4, pp 729-733
TL;DR: In this article, the copolymerization of styrene with substituted ethylene oxides catalyzed by boron trifluoride - diethyl ether has been investigated.
Abstract: The copolymerization of styrene with substituted ethylene oxides catalyzed by boron trifluoride - diethyl ether has been investigated. In all cases, rather low-molecular-weight copolymers were obtained. The copolymerization reactivity of the substituted ethylene oxides with styrene varied with the substituents, in the order of: isobutene oxide>propylene oxide>styrene oxide>epichlorohydrin. This has been explained in terms of cross-propagation or the reaction of the growing oxide cation with styrene. The styrene unit content of the copolymer of styrene and epichlorohydrin increases with an increase in the solvent polarity and with an increase in the temperature. It has been concluded from the experimental results that the copolymerizability of alkylene oxide toward styrene is increased by the introduction of electron-releasing substituents into the oxide and by the use of a polar solvent at a moderate temperature.
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TL;DR: Alkyl vinyl ethers and isobutylene oxide were concurrently copolymerized through cationic vinyl addition and ring opening using B(C6F5)3 as a catalyst to yield multiblock-like copolymers.
Abstract: Alkyl vinyl ethers and isobutylene oxide were concurrently copolymerized through cationic vinyl addition and ring opening using B(C6F5)3 as a catalyst. NMR analyses and acid hydrolysis of the products demonstrated that the copolymerization successfully proceeded through crossover reactions between vinyl and cyclic monomers to yield multiblock-like copolymers. Appropriate catalyst and monomer combinations with suitable reactivities were key for copolymerization.
56 citations
TL;DR: In this article, the authors demonstrate that the structural design of oxirane monomers is highly conducive to crossover reactions in the concurrent cationic vinyl-addition and ring-opening copolymerization of alkyl vinyl ethers and oxiranes.
Abstract: Rational structural design of oxirane monomers is demonstrated here to be highly conducive to crossover reactions in the concurrent cationic vinyl-addition and ring-opening copolymerization of alkyl vinyl ethers and oxiranes. The key to the efficient crossover reactions was the smooth transformation of the once-formed oxirane-derived oxonium ion into the ring-opened carbocation, which then reacted with a vinyl monomer. For example, oxiranes that form resonance-stabilized, allyl-type carbocations (i.e., isoprene monoxide and butadiene monoxide) were polymerized through efficient crossover reactions in copolymerization with isopropyl vinyl ether, yielding copolymers composed of relatively short monomer sequences. In particular, the copolymerization of isoprene monoxide and isopropyl vinyl ether generated random or alternating-rich copolymers. The reaction using an oxirane that forms tertiary carbocations (isobutylene oxide) also proceeded via crossover reactions; however, the crossover frequency was lower, ...
32 citations
TL;DR: In this paper, the authors demonstrated that cyclic acetals and cyclic monomers can copolymerize with sufficient crossover propagation reactions in a controlled manner via the generation of long-lived species.
Abstract: Vinyl monomers and cyclic acetals were demonstrated to copolymerize with sufficient crossover propagation reactions in a controlled manner via the generation of long-lived species. Such unusual propagation reactions, mediated by the active species derived from different types of monomers, were shown to require an appropriate dormant–active equilibrium, achieved via the elaborate design of the initiating systems. The controlled copolymerization of 2-chloroethyl vinyl ether (CEVE) and 1,3-dioxepane (DOP) proceeded using SnCl4 as a catalyst in conjunction with ethyl acetate and 2,6-di-tert-butylpyridine, yielding multiblock-like copolymers as a result of several rounds of crossover reactions per chain. Under the same conditions, when 2-methyl-1,3-dioxolane (MDOL) was used instead of DOP, the polymerization proceeded in a highly controlled manner and involved more frequent crossover reactions. In addition, MDOL underwent almost no homopropagation reactions, unlike DOP. The nature of the cyclic acetal-derived ...
23 citations
TL;DR: In this article, a logarithm of the relative reactivity of cyclic ethers with different basicity and free energy of polymerization was derived for epoxide, oxetane and tetrahydrofuran.
Abstract: Relative reactivity of cyclic ethers, including epoxide, oxetane, tetrahydrofuran, and tetrahydropyran, was evaluated with their basicity and free energy of polymerization The logarithm of relative reactivity, 1/rn , of m-membered ring ethers with i substituents to n-membered ring monomers with j substituents can be expressed by a linear combination of the differences in basicity, Δ(pKb)m·i-n·j, and in free energy, Δ(ΔG)m·i-n·j + γ where, α, β, and γ are constants The changes in basicity and free energy of these compounds can be obtained as Here ak and bk (k = m, n) are constants, σ* is the polar substituent constant by Taft, and Δ(X)(m-n)·2(CH3) (X = ΔG, pKb) are the differences in basicity and free energy between dimethyl-substituted compounds of m- and n-membered rings, respectively
15 citations
TL;DR: In this paper, a review on concurrent cationic vinyl-addition and ring-opening copolymerization of vinyl ethers and oxiranes is presented, with particular emphasis on the strategies required to generate crossover reactions between different types of monomers.
Abstract: In this review, our recent results on the concurrent cationic vinyl-addition and ring-opening copolymerization of vinyl ethers (VEs) and oxiranes are summarized, with particular emphasis on the strategies required to generate crossover reactions between different types of monomers. Most importantly, carbocation generation via the ring-opening reaction of the oxirane-derived oxonium ion is indispensable for the crossover reaction from oxirane to VE. Specifically, oxiranes with substituents that contribute to stabilizing these carbocations are suitable for concurrent copolymerization. Moreover, weak Lewis bases have been found to affect the frequency of crossover reactions through the promotion of the ring-opening reaction. This article also summarizes concurrent cationic vinyl-addition, ring-opening and carbonyl-addition terpolymerization via the one-way cycle of crossover reactions, the copolymerization of an alkoxyoxirane with VEs through the alkoxy group transfer mechanism, and the long-lived species-mediated cationic polymerization of vinyl monomers and cyclic formals. Our recent results in the concurrent cationic vinyl-addition and ring-opening copolymerization of vinyl ethers (VEs) and oxiranes are summarized with particular emphasis on the strategies required to generate crossover reactions between different types of monomers. Most importantly, carbocation generation via the ring-opening reaction of the oxonium ion is indispensable for the crossover reaction from oxirane to VE. This article also summarizes concurrent cationic vinyl-addition, ring-opening and carbonyl-addition terpolymerization, the copolymerization using an alkoxyoxirane through the alkoxy group transfer mechanism and the long-lived species-mediated polymerization using cyclic formals.
8 citations
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TL;DR: In this article, the copolymerization of several vinyl monomers, such as styrene, α-methylstyrene and isobutyl vinyl ether, with 3,3-bis(chloromethyl)oxetane catalyzed by Lewis acids (boron trifluoride-diethyl etherate, stannic chloride and triethylaluminum-water) in methylene chloride at 0°C has been investigated.
Abstract: The copolymerization of several vinyl monomers, such as styrene, α-methylstyrene and isobutyl vinyl ether, with 3,3-bis(chloromethyl)oxetane catalyzed by Lewis acids (boron trifluoride-diethyl etherate, stannic chloride and triethylaluminum-water) in methylene chloride at 0°C has been investigated. In these copolymerizations, the copolymers were not obtained, though a mixture of the corresponding homopolymers was obtained in some cases. The results have been explained on the basis of the differences in reactivity resulting from the structures of the two propagating chain ends.
8 citations
7 citations
TL;DR: In this article, the copolymerization of several vinyl monomers, such as styrene (St), α-methylstyrene and isobutyl vinyl ether, with β-propiolactone (β-PL) as catalyzed by Lewis acids has been investigated in methylene chloride at 0°C.
Abstract: The copolymerization of several vinyl monomers, such as styrene (St), α-methylstyrene and isobutyl vinyl ether, with β-propiolactone (β-PL) as catalyzed by Lewis acids has been investigated in methylene chloride at 0°C. In the copolymerization of β-PL and St using boron trifluoride-diethyl etherate or stannic chloride as a catalyst, the copolymer was obtained. The apparent monomer reactivity ratios were estimated to be as follows:r(β−PL)=0.2; r(St)=20In the other copolymerization systems, the copolymer was not obtained. The mechanism of these copolymerizations has been discussed.
5 citations