On the Degradation and Electron Spin Resonance Spectra of Irradiated Methacrylate Polymers<sup>1</sup>

Kircher, J.F.; Sliemers, F. A.; Markle, R. A.; Gager, W.B.; Leininger, R. I.

doi:10.1021/j100885a028

Cited by 42 publications

(8 citation statements)

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“…The results indicate a G-value of 1.31 ± 0.04 for PMMAs with M n > 55000 which is in agreement with the 1.2 reported by Todd [20). The lower molecular weight PMMAs (G 1.04), however, agree more closely with the 1.1 reported by Kircher et at [21]. These results imply that the G-value is independent of the molecular weight (M n > 55000) [26] and the tacticity of the polymer.…”

Section: Molecular Weight Stereochemistry Effectssupporting

confidence: 90%

Parameters Affecting the Electron Beam Sensitivity of Poly(methyl methacrylate)

et al. 1977

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Poly(methyl methacrylate), PMMA, is used as a model polymer to determine quantitatively the effect of molecular weight, molecular weight distribution, and tacticity on electron beam sensitivity. The heterotactic, syndiotactic, and isotactic stereoforms of PMMA were synthesized with molecular weights ranging from 10 4 to 10 7 and dispersivities from 1.2 to about 10. The G-values as determined by gamma radiation are about 1.3 and are independent of the three parameters. However, the solubility rate of PMMA is very dependent on the tacticity, and the relative solubility rates are in the order syndiotactic < heterotactic-s isotactic. The weightaverage molecular weight ratio was found to give a better correlation with solubility rate ratio than the number-average molecular weight ratio. The molecular size of the developer solvent was shown to have a much greater effect on the solubility rate than the molecular weight of the resist. An optimal developer solvent for PMMA can be systematically selected from a homologous series of nalkyl acetates which enhance the resist sensitivity.

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Section: Molecular Weight Stereochemistry Effectssupporting

confidence: 90%

Parameters Affecting the Electron Beam Sensitivity of Poly(methyl methacrylate)

et al. 1977

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“…[VIlMl = [7?12M2 (2) [v] = K M a Table I1 shows the calculated relative and absolute viscosity average molecular weights of PMMA from GPC and intrinsic viscosity data. A comparison between the results of the two techniques shows relatively good agreement.…”

Section: Discussion Of Resultsmentioning

confidence: 99%

Chain scission efficiency of some polymers in γ‐radiation

Ouano

Johnson

Dawson

et al. 1976

J. Polym. Sci. Polym. Chem. Ed.

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The G values of poly(methyl methacrylates) (PMMA), polycarbonates, and a polylactone for γ‐radiation were determined by using a computer‐assisted GPC as the primary tool for the measurement of the number‐average molecular weights M̄n. The accuracy and precision of the automated GPC were found to have a normalized standard deviation (σ/M̄n) of less than 7%. The G value of PMMA was determined to be essentially independent of molecular weight. For low molecular weight polymers, some nonlinearity in the I/M̄n versus dosage plot was observed at low dosage, i.e., about 1 Mrad.

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“…Both polymers give a nine-line spectrum which consists of an intense five-line and a weak four-line component l37 , 354,387,422,441,845,1035,1131,1206,1207,1466,1471,1480,1672,1685,1682,2050,2054,2123,2125,2171,2339,2428) This nine-line spectrum (Fig. Both polymers give a nine-line spectrum which consists of an intense five-line and a weak four-line component l37 , 354,387,422,441,845,1035,1131,1206,1207,1466,1471,1480,1672,1685,1682,2050,2054,2123,2125,2171,2339,2428) This nine-line spectrum (Fig.…”

Section: Poly(methyl Acrylate) and Poly(methyl Methacrylate)mentioning

confidence: 99%