Cyclopolymerization of metalloid-containing .alpha.,.omega.-dienes. 1,3-Divinyltetramethyldisiloxane 1,3-divinyltetramethyldisilazane, and 1,3-divinylpentamethyldisilazane

Seyferth, D.; Robison, Jennifer L.

doi:10.1021/ma00055a001

Cited by 21 publications

(18 citation statements)

References 11 publications

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“…Seyferth and Robison reported the cyclopolymerization of similar monomers of the type (CH 2 = CHSi-( CH 3) 2 ) 2 X (X = 0, NH, N CH 3 ) by a radical mechanism. 3 In the polymers, five-and six-membered cyclic units, and possibly seven-membered cyclic and acyclic units are present.…”

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confidence: 99%

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Cyclopolymerization Behavior of Bis(dimethylvinylsilyl)methane

Suga

Oku

Takaki

1998

Polym J

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ABSTRACT:Anionic cyclopolymerization of bis(dimethylvinylsilyl)methane (BVSM) in hexane, which affords a polymer having six-membered rings as repeating cyclic units, is investigated. Low polymer yields in the polymerization of BVSM with n-butyllithium (n-BuLi) in the absence of N,N,N',N'-tetramethylethylenediamine (TMEDA) are attributed to cross-linking reactions and association of the propagating ends at -lO'C and elimination of lithium hydride from the propagating end at 40°C. Polymerization with n-BuLiiTMEDA is accompanied, though not frequently, by the abstraction of the methylene proton interposed by two silicon atoms, which forms an inactive anion. This abstraction is caused by the propagating end in the six-membered ring. At high monomer concentration, 0.5 moll-1 , cross-linking reaction is not negligible even in the presence of TMEDA. As initiators, n-, s-, t-BuLi are examined, and only s-BuLi/TMEDA is found to cause the proton abstraction from the methylene interposed by two silicon atoms. The effects of the initiator are explained by the nucleophilicity of BuLi and the steric hindrance in the abstraction. The effects of three amines on the polymerization arc evaluated. TMEDA is the most suitable for the cyclopolymerization of BVSM among them.

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confidence: 99%

“…3 In the polymers, five-and six-membered cyclic units, and possibly seven-membered cyclic and acyclic units are present. Anionic cyclopolymerization has been ever reported solely on 1 ,3-divinylpentamethyldisilazane (X= NCH 3 in the above formula) by Stober and coworkers.…”

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confidence: 99%

Cyclopolymerization Behavior of Bis(dimethylvinylsilyl)methane

Suga

Oku

Takaki

1998

Polym J

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“…In addition, by using the telechelic functionalized siloxane oligomers, a crosslinking of the organic polymer occurs. The free‐radical copolymerization of the styrene and its derivatives with α,ω‐unsaturated siloxane polymers was previously reported 3, 34, 35…”

Section: Resultsmentioning

confidence: 94%

Organic–inorganic polymer hybrids and porous materials obtained on their basis

Cazacu¹,

Drăgan²,

Vlad³

2003

J of Applied Polymer Sci

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Tetramethoxysilane (TMOS) or tetraethoxysilane (TEOS), an organic monomer [methylmethacrylate (MMA) or styrene (St)] and either ␣-propylmethacryloxy--trimethylsiloxy-oligo(dimethylsiloxane) (OMS), as a compatibilizing agent, or ␣,-bis(vinyl) oligo(dimethylsiloxane) (OVS), as compatibilizing and crosslinking agent, were allowed to undergo a sol-gel reaction under acidic condition and in the presence of 2,2Ј-azoisobutyronitrile (AIBN) as a free-radical initiator. The hydrolysis-condensation and in situ free-radical polymerization occur independently, to give a hybrid consisting of both inorganic and organic components. The conversion of the monomers to the proper polymers was monitored by IR spectroscopy and TGA. The resistance of the organic polymers to solvent extraction was also studied. The hybrids were pyrolyzed in an oxidative atmosphere. By decomposition, the organic polymer generated pores in the inorganic matrix. A quantitative evaluation of the characteristics for the resulting porous material was made by determination of the specific area, pore volume, and average radius.

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“…3. The resonance near À41.0 ppm that is shifted far downfield from the monomer is attributed to a 5-atom cyclic structure formed by the condensation between the silicon sites at both ends of the bridge [49,53,54]. Even though the formation of a siloxane bond normally causes an upfield shift, the distortions in electron density and shielding caused by ring formation lead to strong downfield shifts [13,41,55].…”

Section: Characterization Under Nmr-favorable Conditionsmentioning

confidence: 99%