Crystalline Polymers of Methyl Methacrylate

Fox, Thomas; Garrett, B. S.; Goode, William E.; Gratch, Serge; Kincaid, John; Spell, Aldenlee; Stroupe, J. D.

doi:10.1021/ja01540a068

Cited by 353 publications

(124 citation statements)

References 4 publications

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“…1, No. 1,1970 toluene at lower temperatures may be attributed somewhat to this stereoregulation mechanism.…”

Section: Discussionmentioning

confidence: 96%

“…1, No. 1,1970 tion by the AIBN catalyst had about 60 % isotacticity in triads. These results indicate that the mechanism of stereoregulation in this polymerization is different from that in the polymerization of MMA.…”

Section: Discussionmentioning

confidence: 99%

“…1, No. 1,1970 and chloroform were purified and dried in the usual manner. 15 n-BuLi was prepared in n-hexane according to Ziegler's method 16 from n-butyl chloride and metallic lithium under argon atmosphere and was used as a 0.5 mol/1 solution.…”

Section: Methodsmentioning

confidence: 99%

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Stereospecific Polymerization of Trityl, Diphenylmethyl and Benzyl Methacrylates

Yuki

Hatäda

Niinomi

et al. 1970

Polym J

128

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ABSTRACT:Polymerizations of trityl (TMA), diphenylmethyl (DMA) and benzyl (BMA) methacrylates were carried out mainly by n-butyllithium (n-BuLi) and the tacticities of the polymers were studied by NMR spectroscopy. Polymerization of TMA by n-BuLi gave a highly isotactic polymer in toluene as well as in tetrahydrofuran (THF). The polymer obtained in radical polymerization by AIBN catalyst had about 60 % isotacticity in triads.From these results the growing-chain-controlled mechanism was proposed to this polymerization. In the polymerization of DMA by n-BuLi a highly isotactic polymer was obtained in toluene at lower temperatures and a highly syndiotactic one in THF. The radical polymerization gave a predominantly syndiotactic polymer. Temperature dependence of the NMR signal-width of the isotactic polymer indicates that the conformational arrangement of the polymer chain in solution is much rigid up to a fairly higher temperature. These results suggest that the growing-chain-controlled mechanism may contribute to some extent to the stereoregulation of DMA in toluene. BMA behaved very similarly to methyl methacrylate in the polymerization by n-BuLi. Probably the same polymerization mechanisms can be applied for both monomers. Polymerization ofTMA, DMA and BMA by phenylmagnesium bromide or diethylaluminum diphenylamide was also investigated.KEY WORDS Stereospecific Polymerization / Poly (Trityl Methacrylate) / Poly (Diphenylmethyl Methacrylate) / Poly (Benzyl Methacrylate) / Poly (Methyl Methacrylate) / n-Butyllithium / Phenylmagnesium bromide / Diethylaluminum Diphenylamide / Growing-Chain-Controlled Mechanism of Stereoregulation / NMR Spectroscopy / Stereospecific polymerizations of methyl 1 -3 and other alkyl methacrylates 4 -9 by anionic initiator have been extensively studied. However there have been few systematic studies 10 concerning the effect of the ester group on the tacticity of polymer. EXPERIMENTAL MaterialsTMA was prepared from silver methacrylate and trityl chloride in diethyl ether. 12 The crude product was purified by recrystallization from petroleum ether. mp 102-103°C (lit. 12 101-1030C), Anal. Found: C, 84.00; H, 6.08%. Calcd for C23H 200 2 : C, 84.12; H, 6.14%. The NMR spectrum (10 % CC14 solution) showed peaks at 1.90 ppm (singlet, 2.95H) assigned to the methyl protons, 5.49 and 6.13 ppm (two singlets 2.00H) assigned to the p-protons of the vinyl group and about 7.20 ppm (multiplet, 15.2H) assigned to the phenyl protons.In a previous communication 11 we briefly reported the polymerization of trityl methacrylate by anionic and radical initiators and found that this monomer gave a highly isotactic polymer regardless of the polymerization medium, the temperature and the type of initiator. In the present work the polymerizations of trityl (TMA), diphenylmethyl (DMA) and benzyl (BMA) methacrylates were carried out mainly by n-butyllithium (n-BuLi) and the effect of the bulkiness of the ester group on the tacticity of the polymer was investigated. 36DMA was prepared by the reaction of 45 g of silve...

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“…1, No. 1,1970 toluene at lower temperatures may be attributed somewhat to this stereoregulation mechanism.…”

Section: Discussionmentioning

confidence: 96%

Section: Discussionmentioning

confidence: 99%

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Stereospecific Polymerization of Trityl, Diphenylmethyl and Benzyl Methacrylates

Yuki

Hatäda

Niinomi

et al. 1970

Polym J

128

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“…Since the discovery by Fox [1] that syndiotactic poly(methyl methacrylate) (sPMMA) could crystallize in the presence of some solvents, self-aggregation of sPMMA has been extensively studied [2][3][4][5][6][7][8][9]. Spevacek et al [5,6].…”

Section: Introductionmentioning

confidence: 99%

Triblock copolymer based thermoreversible gels. 1: Self-association of sPMMA end-blocks in o-xylene and viscoelasticity of the gels

Jérôme

Teyssié

1997

Polymer

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Syndiotactic poly(methyl methacrylate) (sPMMA)-polybutadiene (PBD)-sPMMA triblock copolymers, or MBM, have been studied in the presence of o-xylene which is a selective solvent for the central PBD block. Syndiotactic PMMA is known to self associate in o-xylene. The central PBD sequence does not prevent the selfassociation of sPMMA from occurring. Actually, this phenomenon contributes to the stability of the gels formed at room temperature. An endotherm is observed at 35°C, which is responsible for a gel-sol transition. The original solutions have been heated up to 80°C and then rapidly cooled down below 35°C and maintained at 10, 20 and 25°C respectively. The self-association of the sPMMA outer blocks, and thus the liquid-solid transition, have been studied at each of these temperatures. Dependence of the gel viscosity on frequency and temperature effects on viscoelasticity has also been investigated.

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“…The melting temperature of the stereocomplex is close to 190°C, which is a very interesting upper service temperature. Stereocomplexation of iPMMA and sPMMA has been extensively investigated since the first report by Fox et al [9] on anomalous WAXS patterns for the related blends. These studies have recently been reviewed by Spevacek and Schneider [10].…”

Section: Introductionmentioning

confidence: 99%

Stereocomplexation of sPMMA-PBD-sPMMA triblock copolymers with isotactic PMMA: 1. Thermal and mechanical properties of stereocomplexes

Dubois

et al. 1997

Polymer

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A novel thermoplastic elastomer consisting of a triblock copolymer (MBM) with outer syndiotactic poly(methyl methacrylate) (sPMMA) blocks associated to an inner polybutadiene (PBD) block has been modified by stereocomplexation with isotactic PMMA (iPMMA). Solution cast films of stereocomplexes have been analysed by thermal analysis as a function of the iPMMA/sPMMA (i/s) mixing ratio and the solvent used for the film casting. Although self-aggregation of iPMMA is currently observed, this phenomenon does not occur in solvent cast films of iPMMA with the MBM copolymers. Extent of complexation depends on the i/s mixing ratio and the casting solvent. At a constant i/s ratio, molecular weight of iPMMA has no significant effect on the extent of stereocomplexation. Thermal stability of the stereocomplexes is only affected by the casting solvent, in contrast to tensile strength which is greatly influenced by the mixing ratio of the two PMMA stereoisomers. Tensile strength is increased when increasing amounts of iPMMA are blended with a triblock copolymer of low PMMA content (e.g. 12%). In case of triblocks of high PMMA content (ca. 30% or higher), a low i/s ratio (

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Crystalline Polymers of Methyl Methacrylate

Cited by 353 publications

References 4 publications

Stereospecific Polymerization of Trityl, Diphenylmethyl and Benzyl Methacrylates

Stereospecific Polymerization of Trityl, Diphenylmethyl and Benzyl Methacrylates

Triblock copolymer based thermoreversible gels. 1: Self-association of sPMMA end-blocks in o-xylene and viscoelasticity of the gels

Stereocomplexation of sPMMA-PBD-sPMMA triblock copolymers with isotactic PMMA: 1. Thermal and mechanical properties of stereocomplexes

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