Mobility of Phosphorescent Solutes in Polymethylmethacrylate

1971 ◽  
Vol 49 (3) ◽  
pp. 515-519 ◽  
Author(s):  
R. J. Woods ◽  
J. F. Manville
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Methyl Methacrylate ◽  
Room Temperature ◽  
Polymer Solutions ◽  
Significant Proportion ◽  
Nuclear Magnetic

Nuclear magnetic resonance measurements upon polymerizing methyl methacrylate solutions show that a significant proportion of the solute molecules (naphthalene, phenanthrene) remain untrapped when the material becomes solid (60–30% residual unsaturation), complete rigid trapping of the solute occurring only as the unsaturation present is reduced to near zero.Phosphorescence measurements show increasing phosphorescence from solid polymethylmethacrylate containing phenanthrene as the residual unsaturation in the polymer is reduced from about 4% to zero, which is attributed to the gradual immobilization of an increasing fraction of the solute molecules as the unsaturation is reduced. Methyl isobutyrate reduces the phosphorescence from solutions of phenanthrene in polymethylmethacrylate at room temperature, but polymer solutions containing methyl isobutyrate and those containing residual unsaturation phosphoresce strongly at 77 °K.

ChemInform Abstract: Quantum Discord in Nuclear Magnetic Resonance Systems at Room Temperature

ChemInform ◽  
2013 ◽  
Vol 44 (9) ◽  
pp. no-no
Author(s):  
J. Maziero ◽  
R. Auccaise ◽  
L. C. Celeri ◽  
D. O. Soares-Pinto ◽  
E. R. deAzevedo ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Quantum Discord ◽  
Room Temperature ◽  
Nuclear Magnetic

scholarly journals The Chemical Shift of the 29Si Nuclear Magnetic Resonance in a Synthetic Single Crystal of Mg2SiO4

1985 ◽  
Vol 40 (2) ◽  
pp. 126-130 ◽  
Author(s):  
N. Weiden ◽  
H. Rager
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Single Crystal ◽  
Angular Dependence ◽  
Room Temperature ◽  
Bond Distance ◽  
Chemical Shift Tensor ◽  
The Individual ◽  
Nuclear Magnetic

The angular dependence of the chemical shift of the 29Si nuclear magnetic resonance has been measured in a synthetic single crystal of Mg2SiO4 (space group Pbnm, Z = 4). The measurements were performed at room temperature at a frequency of 39.758 MHz using the FT-NMR technique. The eigenvalues of the shift tensor with respect to 29Si in TMS are δx = - 38.8 ppm, δv = -55.3 ppm and δz = - 95.4 ppm, with the eigenvector y parallel to c and the eigenvector z forming an angle of 7.5° with a. The results show clearly the influence of the individual S i - O bonds on the chemical shift tensor. The chemical shift along the S i -O bond depends in good approximation exponentially on the S i - O bond distance.

Proton Nuclear Magnetic Resonance Spectroscopic Detection and Determination of Ethylene Glycol Dimethacrylate as a Contaminant of Methyl Methacrylate Raw Material

1995 ◽  
Vol 78 (4) ◽  
pp. 954-958
Author(s):  
George M Hanna ◽  
Cesar A Lau-Cam
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Ethylene Glycol ◽  
Methyl Methacrylate ◽  
Spectroscopic Method ◽  
Ethylene Glycol Dimethacrylate ◽  
Raw Material ◽  
Proton Nuclear Magnetic Resonance ◽  
Glycol Dimethacrylate ◽  
Nuclear Magnetic

Abstract A simple, specific, and accurate proton nuclear magnetic resonance (1H NMR) spectroscopic method is presented for detection and assay of ethylene glycol dimethacrylate dimer as a contaminant of methyl methacrylate monomer. In addition to minimizing exposure of the analyst to the irritant and toxic methacrylic acid esters, the proposed method requires no sample preparation. Quantitations are based on integrals for signals of methylene protons of ethylene glycol dimethacrylate at 4.37 ppm and methyl protons of methyl methacrylate at 3.70 ppm. Analysis of 10 synthetic mixtures of the monomer with 1–11% of dimer yielded a dimer recovery of 100.5 ± 2.05% (mean ± standard deviation). Correspondence (correlation coefficient, r=0.9999) between the amount of dimer added and the amount found was excellent. The proposed method measures as little as 1% of dimer.

Nuclear magnetic resonance studies of ionomers. 5. Spectra of poly (methyl methacrylate-co-4-vinyl pyridine), poly (methyl methacrylate-co-2-methyl-5-vinyl pyridine), and their quaternized derivatives

1987 ◽  
Vol 65 (8) ◽  
pp. 1873-1881 ◽  
Author(s):  
Almeria Natansohn ◽  
Adi Eisenberg
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Methyl Methacrylate ◽  
Pyridine Ring ◽  
Main Chain ◽  
Structural Units ◽  
Poly Methyl Methacrylate ◽  
Nuclear Magnetic Resonance Spectra ◽  
Vinyl Pyridine ◽  
Nuclear Magnetic

Proton and carbon nuclear magnetic resonance spectra in solution of poly (methyl methacrylate-co-4-vinyl pyridine), poly(methyl methacrylate-co-2-methyl-5-vinyl pyridine), and of their derivatives obtained by quaternization with methyl iodide are presented. The vinyl pyridine structural units content of the samples is ca. 10%. In different solvents, the spectra provide information about the sequence distribution and configuration of the copolymers. A "coisotactic" alternating addition, defined as the probability of finding a methoxy group and a pyridine ring neighboring each other on the same side of the main chain, can be estimated as about 0.5 in both cases. This information arises from the splitting of the aromatic and of the methoxy signals (both in proton and carbon spectra). As expected, quaternization does not affect the copolymer configuration. Heteronuclear-correlated two-dimensional spectra can help in assigning the spectra.

Sign in / Sign up

Export Citation Format

Share Document