Autoxidation of tissue lipids. II. Monocarbonyl compounds formed by the autoxidation of methyl eicosapentaenoate,methyl docosahexaenoate,and cod-liver oil

Fatty acid analysis of autoxidized cod-liver oil with a peroxide value of 192 showed significant degradation of only eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids of the linolenate family. Purified, mildly autoxidized cod-liver oil with a peroxide value of 28, methyl eicosapentaenoate, and methyl docosahexaenoate produced carbonyl patterns in agreement with the accepted mechanism for olefinic autoxidation. In all cases the major products were propanal andn-pent-2-enal as predicted, andn-hex-2-enal andn-hept-2-enal as reported in the literature for linolenate. In addition, the same cod-liver oil, which had been heated to 188C in vacuum for 1 hr to decompose completely the hydroperoxides before carbonyl analysis, showed the presence ofn-hepta-2,4-dienal as predicted.     

Interface modification and characterization in three‐component polymer blends

The effect of interface characteristics on the properties of three‐component polymer blends comprising PP/EVOH/mica and PP/EVOH/glass beads (GB) was investigated (polypropylene‐PP, ethylene‐vinylalcohol‐EVOH). The systems selected are based on the binary PP/EVOH immiscible blend representing a semi‐crystalline apolar polymer (PP) and a semi‐crystalline highly polar copolymer (EVOH), where PP serves as the matrix. A series of the binary and three‐component blends with varying compositions was chosen to study the effect of the molding procedure, i.e. compression versus injection molding. The structures observed by SEM analysis consisted of the filler particles engulfed by the EVOH phase, with some of the minor EVOH component dispersed within the PP matrix. The effects of silane treatment (GB/EVOH interface) and compatibilization, using a maleated‐PP compatibilizer (PP/EVOH interface), were studied in relation to the generated structured and properties. The compatibilizer was added in a unique procedure by which the encapsulated GB/EVOH structures were preserved. The characterization methods used included morphology by Scanning Electron Microscopy, thermal properties and crystallization behavior by Differential Scanning Calorimetry, mechanical properties by tensile testing, and dynamic characteristics by Dynamic Mechanical Thermal Analysis. The work has shown that structure‐performance relationships in the three‐component blends can be varied and controlled.     

Autoxidation of fats. II. Preparation and oxidation of methyl oleate-maleic anhydride adduct

Summary The adduct of maleic anhydride and methyl oleate has been prepared and characterized. The physical and chemical properties of the adduct indicate that it is composed of one mole of each of the reactants and that the double bond of methyl oleate has not been saturated. Oxidative fission of the adduct showed that the adduct consisted of a mixture of four isomers which yielded octanoic, nonanoic, suberic, and azelaic acids on ozonolysis. Isolation of these four acids from the fission products indicates that the addition reaction probably proceeds by a mechanism analogous to that proposed by Farmer, Koch, and Sutton for autoxidation. In view of the similarity between the reactions of maleic anhydride and oxygen with unsaturated compounds, the foregoing observations appear to support the free radical chain mechanism for the autoxidation of fats. One of the laboratories of the Bureau of the Agricultural and Industrial Chemistry Agricultural Research Administration, U. S. Department of Agriculture.     

The creation of the 3107 cm hydrogen absorption peak in synthetic diamond single crystals

The 3107 cm⁻¹ hydrogen related local mode was produced in HPHT grown diamonds after annealing at temperatures above 2100°C. A correlation was found between the intensity of the peak and the concentration of nitrogen at different locations of the same specimen. The peak position did not shift in ¹⁵N doped samples.