Vinyl polymerization. 120. Mutual copolymerization of <i>p</i>‐substituted styrenes through radical mechanism

Imoto, Minoru; Kinoshita, Masayoshi; Nishigaki, Masahiko

doi:10.1002/macp.1966.020940124

Cited by 39 publications

(8 citation statements)

References 12 publications

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“…DPPS shows a strong tendency to homopolymerize, while St preferentially copolymerizes with DPPS. This tendency is probably due to the electron‐withdrawing character of the diphenylphosphine substituent, and is in line with the reactivity of other p ‐substituted styrenes with electron‐withdrawing substituents, such as p ‐cyanostyrene ( r StCN = 1.2, r St = 0.19) or p ‐chlorostyrene ( r StCl = 1.1, r St = 0.55) …”

Section: Resultssupporting

confidence: 70%

Phosphorus‐Containing Gradient (Block) Copolymers via RAFT Polymerization and Postpolymerization Modification

Sykes

Harrisson

Keddie

2016

Macro Chemistry & Physics

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Reversible addition-fragmentation chain transfer (RAFT) copolymerization of styrene (St) and 4-(diphenylphosphino)styrene (DPPS) is explored to establish the statistical distribution of the phosphine-functional monomer within the copolymer. RAFT copolymerization of St and DPPS at a variety of feed ratios provides phosphine-functional copolymers of low dispersity at moderate monomer conversion (Ð <1.2 at conv. >60%). In all cases the fraction of DPPS in the resulting polymers is greater than that in the monomer feed. Estimation of copolymerization reactivity ratios indicates DPPS has a strong tendency to homopolymerize whilst St preferentially copolymerizes with DPPS (r DPPS = 4.4; r St = 0.31). The utility of the copolymers as macro-RAFT agents in block copolymer synthesis is demonstrated via chain extension with hydrophilic acrylamide (N,N-dimethylacrylamide (DMAm)) and acrylate a Supporting Information is available online from the Wiley Online Library or from the corresponding author.-2 -(poly(ethylene glycol) methyl ether acrylate (mPEGA); di(ethylene glycol) ethyl ether acrylate (EDEGA)) monomers. Finally access to polymers containing phosphine oxide and phosphonium salt functionalities is shown through post-polymerization modification of the phosphine-containing copolymers.

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Section: Resultssupporting

confidence: 70%

Phosphorus‐Containing Gradient (Block) Copolymers via RAFT Polymerization and Postpolymerization Modification

Sykes

Harrisson

Keddie

2016

Macro Chemistry & Physics

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“…11 Relative reactivity of p-substituted p-methylstyrenes toward maleic anhydride radical were related to p-a + relation and a reaction constant p=-1.13 was reported. 12 Since the maleic an-162 hydride radical probably has a more electrophilic character than the acrylonitrile radical, the polar effect of alkyl substituents may be much smaller than the actual difference in reactivity.…”

Section: Ch3 »Et N-pr N-bu»i-pr>s-bu»t-bumentioning

confidence: 99%

Steric Effects in the Radical Copolymerization of α- and β-Alkylstyrenes

Inaki

Hirose

Nozakura

et al. 1972

Polym J

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ABSTRACT:The effect of alkyl substituents in the radical copolymerizations of aand /3-alkylstyrenes with acrylonitrile was investigated. For a-and /3-methylstyrenes, the radical copolymerizations with methyl acrylate and methacrylonitrile were also carried out. It was shown that when Q and e values are tentativively assigned to these methylstyrenes, the steric effect of the methyl substituent is mainly included in Q values.The relative reactivities within each series of a-alkyl-, cis-p-alkyl-, and trans-/3-alkylstyrenes toward the acrylonitrile radical are related to the steric repulsion effect and the hyperconjugation effect of alkyl substituents. Differences in reactivities among these isomer series are attributed to the resonance factor. KEY WORDSSteric Effect / Radical Copolymerization / a-Alkylstyrene / /3-Alkylstyrene / Acrylonitrile / Methyl Acrylate / Methacrylonitrile / Hyperconjugation / Reactivity / 1, 2-Disubstituted ethylenes are in general reluctant to undergo homopolymerization by the radical mechanism.This low reactivity of internal olefins has been explained by Alfrey, et al., 1 to be due to the steric interaction in the transition state between substituents of the reacting monomer and of the propagating polymer end.The present authors have investigated some aspects of the low reactivity. 2 However, few detailed papers on the steric effect have been reported probably because of the difficulty of separating the steric effect from other factors.It is reported in the study of the radical copolymerization of methyl a-alkylacrylate with styrene that monomer reactivities toward the styryl radical have a linear correlation with Taft's steric substituent constant E 8 • 3 It is also reported that in the case of alkyl methacrylates relative reactivities of the monomers toward the styryl radical are controlled only by the polar effect of substituents of the monomers and have no relation to the steric effects of the substituents. 4 On the other hand, relative reactivities of p-alkylstyrenes toward the acrylonitrile radical were shown to have a linear relation-The steric effect may involve not only the steric interference between the substituent of the monomer and that of the propagating polymer end (ultimate unit), but also interactions between the substituent of the monomer and that of the penultimate unit. It seems necessary to separate the ultimate and the penultimate unit effects in the process of analyzing the copolymerization data in order to discuss the steric effect in detail. The presence of the penultimate unit effect in the radical copolymerization of a-and ,B-alkylstyrenes with acrylonitrile has been shown in the preceding paper. 6 In the present paper, the steric interaction of the substituent of the reacting monomer with that of the ultimate unit in the transition state of the radical copolymerization will be dealt with.In one of our papers, the steric effect in the silver ion complex formation of styrene derivatives was investigated. 7 It was concluded that the equilibrium constant K is deter...

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“…These results suggest that some synergistic dipole-dipole interaction between captive and dative moieties of MAA and EAA monomers and polymers seems to play an important role, not only in the termination but also in other elemental reaction processes, including the propagation. It has been reported that the polarity of styrene derivatives affects the copolymerization reactivity 18 and also the homopolymerization rate 19 even in a radical mechanism. However, there is little work concerning the dependence of the molecular weight on monomer polarity in the field of normal radical polymerization in a homogeneous solution.…”

Section: Resultsmentioning

confidence: 99%

Conversion-Dependent Molecular Weight of the Polymer in Free Radical Polymerization of Captodative Substituted (Acyloxy)acrylates

1997

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The radical homopolymerization of captodatively substituted methyl R-acetoxyacrylate (MAA) is studied by comparing it with that of the R-trifluoroacetoxy, the R-butyryloxy, and the ethyl ester analogs at 40 °C. The yield of the polymer is much influenced by the acyloxy substituents, and the polymer molecular weight increases with conversion in bulk MAA and ethyl ester polymerizations in contrast to other polymerizations. Dilution of the MAA polymerization system, however, results in no increase in the polymer molecular weight during the polymerization. Some polymer-polymer interactions between captive and dative moieties in MAA polymer are discussed on the basis of the measurement of the viscosity of the polymerization system and the polymer solution.

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Vinyl polymerization. 120. Mutual copolymerization of p‐substituted styrenes through radical mechanism

Cited by 39 publications

References 12 publications

Phosphorus‐Containing Gradient (Block) Copolymers via RAFT Polymerization and Postpolymerization Modification

Phosphorus‐Containing Gradient (Block) Copolymers via RAFT Polymerization and Postpolymerization Modification

Steric Effects in the Radical Copolymerization of α- and β-Alkylstyrenes

Conversion-Dependent Molecular Weight of the Polymer in Free Radical Polymerization of Captodative Substituted (Acyloxy)acrylates

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