Vinyl polymerization by cobaltic ions in aqueous solution: Part I. Polymerization of methyl methacrylate

Jijie, K.; Santappa, M.; Mahadevan, V.

doi:10.1002/pol.1966.150040210

Cited by 34 publications

(5 citation statements)

References 25 publications

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“…Both systems demonstrate the presence of the Co(II)—Co(III) species which is consistent with the predictions of the Haber–Weiss scheme. The mechanism presented by Jijie et al5, 6 offers a better explanation of the observed behavior: …”

Section: Resultsmentioning

confidence: 97%

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Microstructure and biocompatibility of composite biomaterials fabricated from titanium and tricalcium phosphate by spark plasma sintering

Mondal

Linh

et al. 2012

J Biomedical Materials Res

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Important issues in developing hydroxyapatite (HAp)- and titanium (Ti)-based composite biomaterials for orthopedic or dental devices include the dissociation of HAp during fabrication and its influences in the microstructure and biocompatibility of the final composite. During the densification by sintering of HAp/Ti composites, Ti reacts with -OH freed from HAp to form TiO2 thus dissociated HAp into Ca3(PO4)2, CaO, CaTiO3, TiP, and so forth. To inhibit this reaction, composites were fabricated with Ti and 30, 50, and 70 vol % β-tricalcium phosphate (β-TCP) instead of HAp by spark plasma sintering at 1200°C. It has been observed that after sintering at 1200°C, Ti also reacted with TCP, but unlike HAp/Ti composites, the final TCP/Ti composites contained significant amounts of unreacted TCP and Ti phases. The initial 70 vol % TCP/Ti composite showed compressive strength of 388.5 MPa, Young's modulus of 3.23 GPa, and Vickers hardness of 361.9 HV after sintering. The in vitro cytotoxicity and proliferation of osteoblast cells on the composites surfaces showed that the addition of a higher amount of TCP with Ti was beneficial by increasing cell viability, cell-composite attachment and proliferation. Osteopontin and collagen type II protein expression from osteoblasts cultured onto the 70% TCP-Ti composite was also higher than other composites and pure Ti. In vivo study verified that within 3 months of implantation in an animal body, 70% TCP-Ti had an excellent bone-implant interface compared with a pure Ti metal implant.

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Section: Resultsmentioning

confidence: 97%

“…In addition to the reactions shown above, termination will occur by the usual transfer and disproportionation reactions. The concentration of the metal‐catalysts is a crucial parameter for the radical polymerization processes to occur 5–7. Cobalt complexes are usually used in conjunction with peroxides and tertiary amines.…”

Section: Introductionmentioning

confidence: 99%

Microstructure and biocompatibility of composite biomaterials fabricated from titanium and tricalcium phosphate by spark plasma sintering

Mondal

Linh

et al. 2012

J Biomedical Materials Res

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“…Both systems demonstrate the presence of the Co(II)-Co(III) species which is consistent with the predictions of the Haber-Weiss scheme. The mechanism presented by Jijie et al 5,6 offers a better explanation of the observed behavior:…”

Section: Differential Scanning Calorimetry Measurementsmentioning

confidence: 92%

“…The concentration of the metalcatalysts is a crucial parameter for the radical polymerization processes to occur. [5][6][7] Cobalt complexes are usually used in conjunction with peroxides and tertiary amines. However, tertiary amines can also act as promoters for the dissociation of organic peroxides and aid the initiation of low temperature polymerization processes.…”

Section: Introductionmentioning

confidence: 99%

Redox initiated free radical polymerization of 4‐methylstyrene

Mortamet

Pethrick

2011

J of Applied Polymer Sci

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Studies of the thermally initiated polymerization of 4-methylstyrene using alkylperoxide in conjunction with cobalt and tertiary amine catalysts are reported. Addition of cobalt salts leads to a facile low temperature initiation of the polymerization process. The polymerization process was investigated using differential scanning calorimetry [DSC] and vibrating probe rheological measurements. Color changes which occur when the cobalt complex and peroxide are combined were studied using UV-visible spectroscopy. The kinetics of polymerization was investigated using two different cobalt complexes. The initiation step in the polymerization is the conversion of the cobalt (II) to cobalt (III). The presence of the tertiary amine does not affect the oxidation state of the cobalt complex. The cobalt (III) complex gives a better rate of conversion than the cobalt (II) complex. The polymerization process is discussed in terms of redox reaction between the cobalt complex and the alkyperoxide. At low temperatures, the rate of conversion obeys simple Arrhenius kinetics. At higher temperatures the effects of gelation and catalysts inhibition influence the polymerization process. The polymerization process is sensitive to the level of available oxygen during the initiation step and inhibition by aldehyde is observed

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“…Duplicate runs were mer, MMA (Sisco-Chem.) was purified by the carried out for the determination of the rate of standard procedure, 16 distilled repeatedly in nimonomer disappearance as well as the rate of cetrogen atmosphere, and stored in dark brown botric ion disappearance. tles at 5ЊC.…”

Section: Methodsmentioning

confidence: 99%

Kinetic and mechanistic studies on the block copolymerization of methyl methacrylate initiated by Ce4+-poly (ethylene glycol) redox system

Nagarajan

Kumari

Srinivasan

1997

J. Appl. Polym. Sci.

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SYNOPSISThe kinetic and mechanistic features of tetravalent cerium-poly(ethylene glycol) (PEG, molecular weight 6000) redox couple initiated block copolymerization of methyl methacrylate (MMA) have been investigated in aqueous acidic medium in the temperature range 30-50ЊC. A plausible reaction scheme has been derived and suitable kinetic expressions have been evaluated based on these observations. It has been concluded that by varying the temperature and concentration of the components of the redox system, it is possible to control the rate of polymerization and the molecular weight of the resulting block copolymer.

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Vinyl polymerization by cobaltic ions in aqueous solution: Part I. Polymerization of methyl methacrylate

Cited by 34 publications

References 25 publications

Microstructure and biocompatibility of composite biomaterials fabricated from titanium and tricalcium phosphate by spark plasma sintering

Microstructure and biocompatibility of composite biomaterials fabricated from titanium and tricalcium phosphate by spark plasma sintering

Redox initiated free radical polymerization of 4‐methylstyrene

Kinetic and mechanistic studies on the block copolymerization of methyl methacrylate initiated by Ce4+-poly (ethylene glycol) redox system

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