Anionic Synthesis of Narrow Molecular Weight Distribution Poly(trimethylvinylsilane) (PTMVS), Polystyrene−PTMVS Block Copolymers, and Poly(phenyldimethylvinylsilane). Conversion of Poly(phenyldimethylvinylsilane) into Poly(fluorodimethylvinylsilane)

Gan, Yaodong; Prakash, G. K. Surya; Oláh, George A.; Weber, William P.; Hogen‐Esch, Thieo E.

doi:10.1021/ma960413d

Cited by 10 publications

(3 citation statements)

References 15 publications

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“…The protodesilylation was performed mainly according to Gan et al12 Thirteen grams of the copolymer (run 3, 0.0043 mol PhSi) was placed in a 500‐mL three‐necked round‐bottom flask with a condenser under an argon atmosphere and dissolved in 200 mL of hot toluene (100–105 °C). The reagent (3 mL of HBF 4 in diethylether, 0.0111 mol) was added slowly through a valve and the reaction was continued for 4 h, after which it was allowed to cool.…”

Section: Methodsmentioning

confidence: 99%

Functionalization of polyethylene/silane copolymers in posttreatment reactions

Lipponen

Seppälä

2004

J. Polym. Sci. A Polym. Chem.

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7-Octenyldimethylphenylsilane was copolymerized with ethylene via Et(Ind) 2 ZrCl 2 methylaluminoxane catalyst system without loss of catalyst activity or decrease in molar mass. The comonomer contents in the polymer samples were at a level of 0.15-1.0 mol % and the reactive phenylsilane groups were posttreated to different alcoxy-and halosilane groups, for example, SiOF, SiOCl, SiOOCH 3 , and SiOOCH 2 CH 3 . The posttreatment reactions had no major effect on the molar masses or on the thermal properties (measured with differential scanning calorimetry) of the copolymers. The reaction pathways were nearly independent of the comonomer contents and the reactions reached 70 -100% conversions.

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Section: Methodsmentioning

confidence: 99%

Functionalization of polyethylene/silane copolymers in posttreatment reactions

Lipponen

Seppälä

2004

J. Polym. Sci. A Polym. Chem.

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“…Thus, depending on the initiator type and polymerization conditions, linear, branched, hyperbranched, and cyclic microstructures are possible for polyethylene (Scheme ). Similar irregular H-transfers resulting in complex microstructures can occur for the anionic polymerizations of some vinyl organosilanes, − α-(aminomethyl)acrylates, and acrylonitriles . In contrast, regioregular isomerizations during propagation are exceedingly rare.…”

Section: Introductionmentioning

confidence: 75%

An Addition–Isomerization Mechanism for the Anionic Polymerization of MesP═CPh₂ and m-XylP═CPh₂

et al. 2018

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We report that the anionic polymerization of P-mesityl and m-xylyl-substituted phosphaalkenes follows an unusual addition–isomerization mechanism. Specifically, the polymerization of ArPCPh2 [Ar = Mes (1a), m-Xyl (1b)] involves the hindered nucleophilic anion intermediate, Ⓟ–P(Ar)–CPh2 –, which undergoes a proton migration from the o-CH3 of the Mes/m-Xyl moiety to the −CPh2 moiety to afford a propagating benzylic anion. This mechanism is supported by the preparation of model compounds MeP(CHPh2)-4,6-Me2C6H2–2-CH2–CPh3 (2a) or MeP(CHPh2)-6-MeC6H3–2-CH2–CPh3 (2b), which were both crystallographically characterized. Polymerization of 1a or 1b in THF solution using n-BuLi (2 mol %) revealed 1H and 13C NMR signals assigned to −CH2– and −CHPh2 groups consistent with an addition–isomerization polymerization mechanism to afford poly(methylenephosphine) 3a or 3b. A large kinetic isotope effect (≤23) was determined for the n-BuLi-initiated polymerization of 1a-d 9 compared to 1a in THF at 50 °C, consistent with C–H (or C–D) activation as the rate-determining step. This C–H activation step was modeled using DFT computations which revealed that the intramolecular proton transfer from the o-CH3 of the Mes moiety to the −CPh2 moiety has an activation energy (E a = +18.5 kcal mol–1). For comparison, this computational value was quite close to the experimentally measured activation energy of propagation ArPCPh2 in THF [E a = 14.0 ± 0.9 kcal mol–1 (1a), 15.6 ± 2.8 kcal mol–1 (1b)].

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“…The strategy, which was for the first time proposed by T. E. Hogen-Esch, et al in 1996, 1 had not been realized until we recently demonstrated that copolymers of di(isobutoxy)methylvinylsilane 3 and styrene prepared by radical copolymerization can be transformed into poly[(vinyl alcohol)-co-styrene]s (Scheme 1). 2 In fact, that is the first example of the synthesis of poly [(vinyl alcohol)-co-styrene].…”

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confidence: 99%

Homopolymerization and Copolymerization with Styrene of Various Alkoxyvinylsilanes and Oxidative Transformation of C-Si Bond in the Resulting Copolymers to Afford Poly[(vinyl alcohol)-co-styrene]s

Ihara

Kurokawa

Itoh

et al. 2008

Polym J

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Radical (co)polymerization behavior of alkoxyvinylsilanes [tri(isobutoxy)vinylsilane 1, triethoxyvinylsilane 2, di(isobutoxy)-methylvinylsilane 3, di(isobutoxy)phenylvinylsilane 4, diethoxymethylvinylsilane 5, and diethoxyphenylvinylsilane 6] was systematically investigated. Homopolymerization and copolymerization with styrene of these alkoxyvinylsilanes were performed under various conditions in order to find appropriate initiating systems for the radical polymerizations. Transformation of some of the copolymers into poly[(vinyl alcohol)-co-styrene]s was examined via oxidative cleavage of the Si-C bonds in the alkoxyvinylsilane repeating units.KEY WORDS: Radical Polymerization / Copolymerization / Poly(alkoxyvinylsilane) / Polystyrene / Polymer Reaction / Radical polymerization of vinylsilanes followed by oxidative cleavage of C-Si bonds in the resulting repeating units could be a useful method for preparing poly(vinyl alcohol) (PVA) and its derivatives. The strategy, which was for the first time proposed by T. E. Hogen-Esch, et al. in 1996, 1 had not been realized until we recently demonstrated that copolymers of di(isobutoxy)methylvinylsilane 3 and styrene prepared by radical copolymerization can be transformed into poly[(vinyl alcohol)-co-styrene]s (Scheme 1).2 In fact, that is the first example of the synthesis of poly[(vinyl alcohol)-co-styrene]. Although the copolymer should be prepared by hydrolysis of poly[(vinyl acetate)-co-styrene], the synthesis of the precursor copolymer via radical copolymerization is not practical due to the large difference of the monomer reactivity ratios [r 1 (styrene) = 56, r 2 (vinyl acetate) = 0.01].3 On the other hand, the oxidation of the homopolymer poly3 afforded an insoluble product, whose elemental analysis agreed well with the composition of PVA. 2Although the results are highly promising for further development, the problem with the process is that the copolymerization initiated by 1,1 0 -azobis(cyclohexane-1-carbonitrile) (VAZO) at 130 C did not proceed efficiently, giving rather low molecular weight copolymers in low yields (M n < 8600, yield < 35%). Accordingly, in order to establish this strategy as a practical synthetic method for polymeric materials containing vinyl alcohol (VA) repeating units, we should find more efficient conditions for the polymerization of 3 or other vinylsilanes, which can be polymerized to give higher molecular weight (co)polymers and can provide an appropriate C-Si bond for the following oxidative cleavage.According to the literatures, 4 the requirement for the oxidative cleavage to successfully proceed is the presence of at least one -OR or -NR 2 group on Si. Thus, as for alkoxyvinylsilanes, because we have found that the repeating unit of a monoalkoxyvinylsilane [dimethyl(isobutoxy)vinylsilane] in the copolymer with styrene could not be efficiently transformed into VA repeating unit after oxidation, 2 we have trialkoxyvinylsilane and dialkoxyvinylsilane as candidates. Whereas there have been some reports and patents describing polym...

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Anionic Synthesis of Narrow Molecular Weight Distribution Poly(trimethylvinylsilane) (PTMVS), Polystyrene−PTMVS Block Copolymers, and Poly(phenyldimethylvinylsilane). Conversion of Poly(phenyldimethylvinylsilane) into Poly(fluorodimethylvinylsilane)

Cited by 10 publications

References 15 publications

Functionalization of polyethylene/silane copolymers in posttreatment reactions

Functionalization of polyethylene/silane copolymers in posttreatment reactions

An Addition–Isomerization Mechanism for the Anionic Polymerization of MesP═CPh₂ and m-XylP═CPh₂

Homopolymerization and Copolymerization with Styrene of Various Alkoxyvinylsilanes and Oxidative Transformation of C-Si Bond in the Resulting Copolymers to Afford Poly[(vinyl alcohol)-co-styrene]s

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Anionic Synthesis of Narrow Molecular Weight Distribution Poly(trimethylvinylsilane) (PTMVS), Polystyrene−PTMVS Block Copolymers, and Poly(phenyldimethylvinylsilane). Conversion of Poly(phenyldimethylvinylsilane) into Poly(fluorodimethylvinylsilane)

Cited by 10 publications

References 15 publications

Functionalization of polyethylene/silane copolymers in posttreatment reactions

Functionalization of polyethylene/silane copolymers in posttreatment reactions

An Addition–Isomerization Mechanism for the Anionic Polymerization of MesP═CPh2 and m-XylP═CPh2

Homopolymerization and Copolymerization with Styrene of Various Alkoxyvinylsilanes and Oxidative Transformation of C-Si Bond in the Resulting Copolymers to Afford Poly[(vinyl alcohol)-co-styrene]s

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An Addition–Isomerization Mechanism for the Anionic Polymerization of MesP═CPh₂ and m-XylP═CPh₂