Cationic polymerization of 1,3-pentadiene in the presence of vanadium oxychloride

Розенцвет, В. А.; Козлов, В. Г.; Korovina, Nelly A.; Monakov, Yu. B.

doi:10.1134/s1560090410090095

Cited by 10 publications

(43 citation statements)

References 7 publications

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“…It is known that the cationic polymerization of 1,3‐pentadiene is co‐initiated by a wide range of Lewis acids such as AlCl 3 , FeCl 3 , SnCl 4 , BF 3 OEt 2 , VOCl 3 , and TiCl 4 . The main feature of TiCl 4 ‐based initiating systems is their low activity in the polymerization of 1,3‐dienes in the absence of purposely added initiators such as water, hydrochloric acid, organic acids, and so on, while the addition to the system of protic compounds or cationogens allowed to increase the rate of polymerization of 1,3‐dienes significantly .…”

Section: Introductionmentioning

confidence: 99%

“…The TiCl 4 ‐co‐initiated cationic polymerization of 1,3‐dienes in conjunction with water, acetone, trichloroacetic acid, trifluoroacetic acid, tert ‐butyl esters of these acids, cumyl acetate, cumyl methyl ether, dimethylallyl bromide, and dimethylallyl alcohol has been investigated. The obtained poly(1,3‐diene)s are characterized by reduced unsaturation that was explained either by intramolecular cyclization or branching due to the chain transfer to polymer . The unsaturated part of the polymer chain consists mainly of trans ‐1,4‐structures …”

Section: Introductionmentioning

confidence: 99%

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A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization I: Polymerization of 1,3‐Pentadiene with ^tBuCl/TiCl₄ Initiating System: Kinetic and Mechanistic Study

Розенцвет

Козлов

Korovina

et al. 2013

Macro Chemistry & Physics

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The cationic polymerization of 1,3-pentadiene using a tert -butyl chloride ( t BuCl)/TiCl 4 initiating system in CH 2 Cl 2 at different reaction conditions is reported. It is shown that the reaction rate increases with the increase of the t BuCl/TiCl 4 molar ratio, while the molecular weight distribution becomes narrower. Well-defi ned oligo(1,3-pentadiene)s (M n ≤ 3500 g mol − 1 ; M w /M n ≤ 3.0) are obtained at high t BuCl/TiCl 4 molar ratio (340) and low temperature (-78 °C). 1 H and 13 C NMR spectroscopy studies reveal the presence of tert -butyl head and -CH 2 -Cl end groups. The number-average functionalities ( F n s) at the α -and ω -ends are calculated to be F n ( t Bu) > 1 and F n (Cl) < 1, respectively. The general mechanism of 1,3-pentadiene polymerization is proposed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization I: Polymerization of 1,3‐Pentadiene with ^tBuCl/TiCl₄ Initiating System: Kinetic and Mechanistic Study

Розенцвет

Козлов

Korovina

et al. 2013

Macro Chemistry & Physics

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“…Moreover, the cationic polymerization of 1,3 dienes as a rule has a pronounced non stationary character [2][3][4][5]. This feature hinders the correct use of known methods for the calculation of propagation rate con stants [1,6,7] based on the measurement of number average polymerization degree.…”

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confidence: 99%

“…This work deals with the development of a new method for the determination of propagation rate constants for the cationic polymerization of 1,3 dienes. The cationic polymerization of 1,3 pentadi ene catalyzed by TiCl 4 -CF 3 COOD is used as an example.Preparation of initial reagents and polymerization procedure are described in [4,5]. The catalyst was deactivated with a mixture of propylene oxide and methanol [5].…”

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On the issue of the propagation rate constant for the cationic polymerization of 1,3-dienes

et al. 2013

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A characteristic feature of the cationic polymeriza tion of conjugated dienes is the ability of the double bonds of a macromolecule to undergo further trans formations, which result in branched structures and a decrease in the unsaturation of polydienes [1,2]. Moreover, the cationic polymerization of 1,3 dienes as a rule has a pronounced non stationary character [2][3][4][5]. This feature hinders the correct use of known methods for the calculation of propagation rate con stants [1,6,7] based on the measurement of number average polymerization degree. At the same time, there is no information in the literature on the propa gation and termination rate constants of the cationic polymerization of 1,3 dienes. This work deals with the development of a new method for the determination of propagation rate constants for the cationic polymerization of 1,3 dienes. The cationic polymerization of 1,3 pentadi ene catalyzed by TiCl 4 -CF 3 COOD is used as an example.Preparation of initial reagents and polymerization procedure are described in [4,5]. The catalyst was deactivated with a mixture of propylene oxide and methanol [5]. Deuterated trifluoroacetic acid (DTFA, Fluka, >99%) and deuterated dimethyl sulfoxide (Fluka, >99.9%) were used without additional purifi cation. The synthesized polymers prior to analyses were purified from catalyst residues by column chro matography on silica gel (Silica Gel 60, Fluka), using chloroform as an eluent. The 1 H and 2 H NMR spectra of the polymer (CDCl 3 solvent) were recorded on a Bruker Avance 600 spectrometer with a scan number of at least 800 and a repetition time of 5 s. Deuterium content in the polymer was calculated relative to the known weight of internal reference introduced into a polymer solution.The polymerization of 1,3 pentadiene in the pres ence of the TiCl 4 -DTFA catalytic system in a methyl ene chloride medium proceeds at a high initial rate (Fig. 1, curve 2). The polymerization rate decreases when the monomer conversion reaches 45-50 wt %, and further polymerization of 1,3 pentadiene pro ceeds at a rather low constant rate until complete monomer consumption. In the absence of DTFA in the catalytic system, the polymerization under the action of TiCl 4 proceeds at a very low rate (Fig. 1, curve 1). The prepared poly(1,3 pentadiene) (PPD) has a molecular weight of 3.7-3.8 × 10 3 g/mol and a dispersity of 2.5-2.6.The formation of the active center can be thought to result from the reaction of DTFA and TiCl 4 fol lowed by the insertion of deuterium into the first 1,3 pentadiene molecule (Scheme 1). 80 0 3 0 Time, s Conversion, wt % 60 40 20 20 10 2 1 Fig. 1. Time dependence of 1,3 pentadiene conversion upon polymerization in the presence of (1) TiCl 4 and (2) TiCl 4 -DTFA catalytic system. Polymerization condi tions for all figures: [DTFA]/[TiCl 4 ] = 2.0, [TiCl 4 ] = 1.5 × 10 -2 mol/L, [C 5 H 8 ] = 4.0 mol/L, -78°C, CH 2 Cl 2 .

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Cationic polymerization of 1,3‐pentadiene coinitiated by zinc halides

Розенцвет¹,

Козлов²,

Korovina³

et al. 2012

J of Applied Polymer Sci

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Technology of industrial production of liquid rubber under trademark ''SKOP'' is based on the cationic polymerization of 1,3-penadiene (piperylene) in the presence of TiCl 4 or AlCl 3 -based catalytic systems. The disadvantage of these catalytic systems is the high probability of formation of branched and insoluble fractions due to the chain transfer to polymer. This deteriorates the useful qualities of SKOP. Here we propose the new initiating systems for the cationic polymerization of 1,3-pentadiene based on the homogeneous (dissolved in a minimal amount of diethyl ether) zinc halides (ZnCl 2 and ZnBr 2 ) as coinitiators and hydrochloric acid, tertbutyl chloride or trichloroacetic acid as initiators. These initiating systems allow to synthesize fully soluble low molecular weight (M n ¼ 1000-3000 g mol À1 ) poly(1,3-pentadiene)s with relatively narrow molecular weight distribution (M w /M n < 2.0), which do not contain any high molecular weight and insoluble fractions in the whole range of monomer conversion. The polymers synthesized in the presence of zinc halides possess the same microstructure that those prepared with TiCl 4 as coinitiator.

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Cationic polymerization of 1,3-pentadiene in the presence of vanadium oxychloride

Cited by 10 publications

References 7 publications

A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization I: Polymerization of 1,3‐Pentadiene with ^tBuCl/TiCl₄ Initiating System: Kinetic and Mechanistic Study

A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization I: Polymerization of 1,3‐Pentadiene with ^tBuCl/TiCl₄ Initiating System: Kinetic and Mechanistic Study

On the issue of the propagation rate constant for the cationic polymerization of 1,3-dienes

Cationic polymerization of 1,3‐pentadiene coinitiated by zinc halides

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Cationic polymerization of 1,3-pentadiene in the presence of vanadium oxychloride

Cited by 10 publications

References 7 publications

A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization I: Polymerization of 1,3‐Pentadiene with tBuCl/TiCl4 Initiating System: Kinetic and Mechanistic Study

A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization I: Polymerization of 1,3‐Pentadiene with tBuCl/TiCl4 Initiating System: Kinetic and Mechanistic Study

On the issue of the propagation rate constant for the cationic polymerization of 1,3-dienes

Cationic polymerization of 1,3‐pentadiene coinitiated by zinc halides

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A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization I: Polymerization of 1,3‐Pentadiene with ^tBuCl/TiCl₄ Initiating System: Kinetic and Mechanistic Study

A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization I: Polymerization of 1,3‐Pentadiene with ^tBuCl/TiCl₄ Initiating System: Kinetic and Mechanistic Study