The photo‐oxidation products of ethyl N‐phenyl‐carbamate (EPC) were identified as ethyl o‐aminobenzoate, ethyl p‐aminobenzoate, aniline, water, carbon dioxide, azo compounds, and other colored material. The ethylaminobenzoates, formed by intramolecular rearrangement of EPC, were precursors of the azo and colored products. Diethyl 4,4′‐azobenzenedicarboxylate was produced by the ultraviolet irradiation of the precursor, ethyl p‐aminobenzoate, in the presence of oxygen. Benzophenone and anthraquinone, as the triplet donors, sensitized the photo‐oxidation of EPC. Quantum yields of photolysis of EPC were measured. The photorearrangement reaction was inhibited by the polar solvent (ethanol). The presence of metal ions and phenyl isocyanate in EPC showed no effect on the oxygen consumption rate.

synopsisNuclear magnetic resonance, infrared, and ultraviolet spectroscopy were used to elucidate the structure of oxidized polystyrene. To identify the nuclear magnetic resonance peaks of the degraded polystyrene, deuterated polystyrenes were synthesized and degraded. The primary structure present in the degraded polystyrene was found to be an aromatic carbonyl group. It was shown that this structure was formed regardless of the presence of ultraviolet light and was also present when polystyrene was degraded in carbon tetrachloride solution. When polystyrene waa degraded in carbon tetrachloride solution, stable polymeric peroxides were formed in a concentration of 4 peroxide groups for every lo00 styrene units.

The investigation of the thermal degradation or pyrolysis of vinyl polymers has been pursued from the theoretical and the experimental standpoint for polystyrene,' polymethyl methacrylate,2 and polythene.3 The degradation of the first two polymers seems to be predominantly a depolymerization, while that of polythene is a process of random chain scission. The methods have been weight loss, viscosity studies, molecular weight distribution, osmotic measurements, and infrared analysis. The oxidative degradation of vinyl polymers has been extensively studied by Tobolsky,' who emphasizes that a combination of analytical methods is necessary for a complete analysis of such a complex process.This paper presents the oxidative degradation of polyvinyl formal at high temperatures, studied by the infrared method in conjunction with weight loss, color development, and chemical analysis. Polyvinyl formal, like many other materials used in electrical insulation, undergoes severe changes in its physical, chemical, and electrical properties when exposed to high temperatures in the presence of air. It changes from a strawcolored resin of good Electrical properties to a deep brown embrittled material of high dielectric constant. Loss of solubility precludes such methods as viscosity measurements as methods of analysis during degradation. However, the infrared spectrum, because of its sensitivity to molecular structure and structural changes, has been valuable in detecting the changes in the polymer during degradation.. EXPERIMENTAL Materials. Commercial polyvinyl formal resin, or Formvar "E" obtained from Shawinigan Products Corporation, was analyzed by the manufacturers to contain 6% free hydroxyl groups, 12% acetate groups, 0.9% moisture, and 0.14% free hydroxyl acid. The hemi-formal content was believed to be insignificant; the molecular weight was approximate!y 22,000. Osmotic measurementst made in this laboratory on dioxane solutions of * The research described in this paper was carried out under sponsorship by the Office t

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Proton chemical shifts of cyclopentadienyl ring protons in a series of substituted bis(cyclopentadienyl)titanium compounds have been correlated with electronegativities of the ligands on titanium.A similar correlation of ring proton shifts with ligand electronegativities was found for a series of methyl-substituted titanocene halides and titanocene dihalides, and a reverse trend was noted when the chemical shift of the methyl protons was considered in the methyl-substituted series. In a series of substituted diaryltitanocenes the average chemical shift of ortho and meta protons relative to the chemical shift of a reference (bis(cyclopentadienyl)diphenyltitanium) as well as the chemical shifts of the cyclopentadienyl ring protons give a linear correlation with Taft's inductive and resonance parameters and a satisfactory Hammett line.

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The infrared spectrum of gaseous dimethylphosphine and the Raman spectrum of the liquid have been obtained. Tentative assignments for the fundamental vibrational frequencies and an interpretation of the observed spectra are given.

The pyrolysis of a polyurethane obtained from tolylene 2,4‐diisocyanate and ethylene glycol was studied in nitrogen, air, and oxygen from the double aspect of structural change and color formation. The dissociation of the polymer into its components followed by further reactions liberates diisocyanate, the corresponding diamine, and the polypseudourea ether, as well as other degradation products. The color is attributed to the yellowing of TDI, the oxidation of the diamine, and the presence of the polypseudourea ether.