Polymers oxidation with VO(acac)2 complex

Gerbase, Annelise Engel; Gregório, José Ribeiro; Martinelli, Márcia; Holleben, Maria Luiza Ambros von; Jacobi, Marly Antônia Maldaner; Freitas, L. de Lucca; Calcagno, Carmen Iara Walter; Mendes, Ana Néry Furlan; Pires, Marcia Lopes

doi:10.1016/s0920-5861(99)00332-6

Cited by 17 publications

(7 citation statements)

References 19 publications

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“…Also, epoxides are one of the most important intermediate groups for the synthesis of oxygen-containing organic compounds both in industry and in academic laboratories. 1 There are several experimental methods for the epoxidation of C¼C bonds in the structure of polymers such as polybutadiene and hydroxyl terminated polybutadiene (HTPB): thermal oxidation, 2 oxidation with Vo (acac) 2 complex, 3 epoxidation with peroxides and hydro peroxides 4 such as tert-butyl hydro peroxide (TBHP), 5 and epoxidation with peracids 6 such as m-chloroperbenzoic acid (m-CPBA). 7 However, these methods are not without their disadvantages.…”

Section: Introductionmentioning

confidence: 99%

Performance of dimethyl dioxirane/nano-TiO₂ on epoxidation of polybutadiene and hydroxyl terminated polybutadiene

Nikje

Hajifatheali²

2012

Journal of Elastomers & Plastics

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Polybutadiene and hydroxyl terminated polybutadiene (HTPB) were epoxidized using in situ-generated dimethyl dioxirane (DMD) as an oxidant in the presence of nano-TiO 2 at 25 C. Reaction time and different percentages of catalyst/Oxone 1 (w/w) were also examined. The capability of different kinds of double bonds to be epoxidized was studied in detail at various reaction times, and the products were characterized using nuclear magnetic resonance ( 1 HNMR), 13 CNMR, and Fourier transform infrared (FT-IR) techniques, with no side reaction being detected. The results indicate that using nano-TiO 2 as a catalyst increases the epoxidation yield, especially of cis double bonds.

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Section: Introductionmentioning

confidence: 99%

Performance of dimethyl dioxirane/nano-TiO₂ on epoxidation of polybutadiene and hydroxyl terminated polybutadiene

Nikje

Hajifatheali²

2012

Journal of Elastomers & Plastics

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“…The polymers containing functional groups are used for the production of materials having such important characteristics as high adhesion, chemical and thermal stability, etc 1–4. Such polymers are commonly synthesized by the copolymerization of dienes with the monomers containing functional groups or by the chemical modification of suitable initial polymers 2–6. The latter approach is most widely used with polydienes containing CC bonds.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of functionalized liquid rubbers from polyisoprene

Дубков

Семиколенов

Иванов

et al. 2009

J of Applied Polymer Sci

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Noncatalytic transformation of cis-1,4-polyisoprene rubber (M n ¼ 320,000) into functionalized liquid rubbers containing various amounts of carbonyl groups was studied. The process is performed via selective carboxidation of the polymer C¼ ¼C bonds by nitrous oxide (N 2 O) in the temperature range of 180-230 C and under 3-6 MPa pressure. The carboxidation proceeds by the nonradical type mechanism involving the 1,3-dipolar cycloaddition of N 2 O to the C¼ ¼C bond. The main route of the reaction (ca. 65%) proceeds without cleavage of the internal C¼ ¼C bonds and leads to the formation of ketone groups in the polymer backbone. The second route (ca. 35%) includes the cleavage of C¼ ¼C bonds, yielding the molecules of a smaller size. This route results in a manifold decrease of the molecular weight, which, depending on the carboxidation degree, may be more than two orders of magnitude less than that of the parent rubber. A series of functionalized liquid rubbers having M n value from 1000 to 19,000, and the oxygen content from 0.3 to 3.9 wt % was obtained in the form of the liquid unsaturated polyketones. Similar polyketones can also be prepared by carboxidation of the natural rubber.

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“…The methods for preparing functionalized polymers and their properties and applications have been considered in a number of recent books and reviews 4–7. Such materials are generally synthesized by the copolymerization of dienes with monomers containing functional groups or by chemical modification via postpolymerization reactions over double bonds 7–9…”

Section: Introductionmentioning

confidence: 99%

New reaction for the preparation of liquid rubber

Дубков¹,

Семиколенов²,

Babushkin³

et al. 2006

J. Polym. Sci. A Polym. Chem.

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The article reports on the noncatalytic transformation of a polybutadiene (number‐average molecular weight = 128,000) into a functionalized liquid rubber via the carboxidation of the polymer CC bonds by nitrous oxide. The reaction was conducted in a benzene solution at 160–230 °C and a pressure of 3–6 MPa. The carboxidation mechanism was determined. The main route (95%) of the reaction proceeded without cleavage of CC bonds and led to the formation of ketone groups in the polymer backbone. A minor route (5%) of the reaction proceeded with the cleavage of CC bonds, yielding two smaller fragments containing aldehyde and vinyl end groups. The availability of the cleavage route could lead to a dramatic decrease in the molecular weight, which, depending on the carboxidation degree, could be 1–2 orders of magnitude less than that of the initial material. Thus, the carboxidation of more than 15% of the polybutadiene CC bonds transformed it into a CO‐functionalized liquid rubber with a narrow molecular weight distribution. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2510–2520, 2006

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Polymers oxidation with VO(acac)2 complex

Cited by 17 publications

References 19 publications

Performance of dimethyl dioxirane/nano-TiO₂ on epoxidation of polybutadiene and hydroxyl terminated polybutadiene

Performance of dimethyl dioxirane/nano-TiO₂ on epoxidation of polybutadiene and hydroxyl terminated polybutadiene

Synthesis of functionalized liquid rubbers from polyisoprene

New reaction for the preparation of liquid rubber

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Polymers oxidation with VO(acac)2 complex

Cited by 17 publications

References 19 publications

Performance of dimethyl dioxirane/nano-TiO2 on epoxidation of polybutadiene and hydroxyl terminated polybutadiene

Performance of dimethyl dioxirane/nano-TiO2 on epoxidation of polybutadiene and hydroxyl terminated polybutadiene

Synthesis of functionalized liquid rubbers from polyisoprene

New reaction for the preparation of liquid rubber

Contact Info

Product

Resources

About

Performance of dimethyl dioxirane/nano-TiO₂ on epoxidation of polybutadiene and hydroxyl terminated polybutadiene

Performance of dimethyl dioxirane/nano-TiO₂ on epoxidation of polybutadiene and hydroxyl terminated polybutadiene