Synthetic approaches to atactic poly(methyl methacrylate)

Graham, Roger; Dunkelberger, David L.; Panchak, John R.

doi:10.1002/pol.1962.1205916824

Cited by 5 publications

(2 citation statements)

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“…This assumption is justified, for example, in radical polymerization of methyl methacrylate. For this case there are two rate constants k i and ks for the two chain-growth reactions, and ·See literature [16,192,193,202,210,244,256,293,327,391,392,403,436,477,479,510,511,701,707,711].…”

Section: Study Of Polymerizationmentioning

confidence: 99%

“…In a study of the anionic polymerization of methyl methacrylate, it was found [210] that the fraction of isotactic links is greatest in polymers obtained with organolithium initiators and falls with a change to sodium and potassium compounds; polymers of higher isotacticity are formed in nonpolar solvents, while the effect of temperature is insignificant. By controlling the synthesis through NMR measurements it was possible to select polymerization conditions which yield a purely atactic polymethyl methacrylate [327] with 1* ::::; 0; H * = 0.51; S* = 0.49.…”

Section: (V-i)mentioning

confidence: 99%

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The NMR of Polymers

Slonim¹,

Lyubimov²

1995

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Section: Study Of Polymerizationmentioning

confidence: 99%

Section: (V-i)mentioning

confidence: 99%

The NMR of Polymers

Slonim¹,

Lyubimov²

1995

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Glass transition temperatures of poly(methyl methacrylate) plasticized with low concentrations of monomer and diethyl phthalate

Dudek

Lohr

1965

J of Applied Polymer Sci

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SynopsisThe effect of low plasticizer concentrations on the glass transition temperature of poly(methy1 methacrylate) (PMMA) has been studied experimentally for diethyl phthalate (DEP) and methyl methacrylate (MMA) as plasticizers. Volume dilatometry, differential thermal analysis, and a torsional pendulum were used to determine glass transition temperatures. The monomer-plasticized PMMA samples were prepared by polymerizing MMA to a limiting conversion which was found to depend primarily on temperature. At temperatures slightly above the glass transition temperature of a MMA-PMMA system, a polymerization reaction occurred at a rate rapid enough to complicate the interpretation of the dilatometric and differential thermal analysis methods for determining the glass transition temperature. However, the torsional pendulum method could be used since it did not require measurements to be made at temperatures where polymerization could occur. The differential thermal analysis resultq showed that the temperature at which the polymerization reaction was first detectable was related to the glass transition temperature of the MMA-PMMA solution. The measured glass transition temperatures were compared with the predictions of the theories of Fox, Kelley, and Bueche, and Dimarioz and Gibbs on the effect of plasticizer concentration on the depression of the glass transition temperature. * Present address: Lord Manufacturing Company, Erie, Pennsylvania. 3795 3796 T. J. DUDEK AND J. J. LOIIHaccepted dilatometric method were complicated by polymerization in the region of the glass transition temperature. This made the determination of T , from the dilatometric data potentially unreliable. For this reason, differential thermal analysis (hereafter referred to as DTA) and torsional pendulum methods of measuring glass transition temperatures were also evaluated. Glass transition temperatures measured by these two methods were related to the dilatometrically determined T , for a PMMA-DEP system which is free of the complications of polymerization.This relation is then used to determine the "true" dilatometric To of the PMMA-MMA system from the glass transition temperatures measured by the torsional pendulum method and by DTA. Finally, the FOX,^,^ Kelley-Bueche,' and Dimarzio-Gibbs5 relations of glass transition temperature depression due to plasticizer content are compared with the measured T,. EXPERIMENTAL MaterialsMethyl methacrylate (MMA) obtained from the Rohm and Haas Company was washed with 5% NaOH and with water to remove the inhibitor and was then dried and distilled. A middle fraction was collected for use in the preparation of polymer samples. -Gas chromatography showed that the distilled monomer was free of impurities.Diethyl phthalate (DEP) (Eastman, White Label) was used as received, as was cY,a'-azobisisobutyronitrile (AIBN) (duPont's Vazo).

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The interpretation of tacticity measurements

Miller¹

1963

Polymer Engineering & Sci

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To date, quantitative stereochemical data are available for a few polymers only. A convenient and graphic representation of this data has been developed. Analysis of this data yields two parameters characterizing a polymer, one representing the tacticity and the other representing the nature of the tactic sequence distribution. The statistical parameters obtained may be related to the polymerization conditions and, hence, to the mechanism of stereoregulation. Furthermore they may be related to a number of physical properties, such as melting point, equilibrium crystallinity, and melting curve. Thus, the proper analysis of the NMR data supplies a link between polymerization conditions and the properties of the resulting polymer.

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Synthetic approaches to atactic poly(methyl methacrylate)

Cited by 5 publications

References 10 publications

The NMR of Polymers

The NMR of Polymers

Glass transition temperatures of poly(methyl methacrylate) plasticized with low concentrations of monomer and diethyl phthalate

The interpretation of tacticity measurements

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