Quantitative fatty acid analysis of vegetable oils by gas-liquid chromatography

Summary The fatty acid composition of a number of vegetable oils and of two synthetic mixtures of methyl esters are compared by gas-liquid chromatography and by standard methods. The calculated iodine values from G.L.P.C. results are in good agreement with measured iodine values and are indicative of the reliability of the G.L.P.C. values. Standard methods gave lower values for linoleic acid and higher values for linolenic acid than did G.L.P.C. This deviation was particularly evident in oils with a high proportion of linolenic acid,e.g., linseed oil. The results of G.L.P.C. are considered to be accurate to within one unit percentage. Thermal stability of the polyester polymers can be improved by using 1,4-butanediol or ethylene glycol as the polyols instead of diethylene glycol. Issued as N.R.C. No. 5373. Presented at 32nd annual fall meeting, American Oil Chemists' Society, October 20–22, 1958, Chicago, Ill. National Research Council of Canada Postdoctorate Fellow, 1957     

Influence of genetics,environment and admixtures on low erucic acid rapeseed in Canada

Single plant isolates in theBrassica napus andBrassica campestris species of rapeseed yielded glyceride oil containing small amounts of erucic acid. Agronomically suitable varieties were grown commercially in 1971 as the first phase in a changeover of Canadian rapeseed production from varieties with erucic contents of 20–45% to low erucic acid varieties. A program to monitor the erucic content by gas chromatographic analysis in the stages of production, handling and transportation from seed to export shipment was undertaken to evaluate the effects of genetics, environment and admixture. The individual increase in erucic content ranged from 0.5 to 1.0, resulting in total increases of 1–2%. NRCC No. 13471. One of six papers presented in the symposium “Rapeseed Marketing and Breeding,” AOCS Meeting, Ottawa, September 1972.     

Grafting onto polyester fibers. III. Electrokinetic properties of acrylic acid and acrylonitrile-grafted polyester fibers in the presence of cationic dyes

The electrokinetic properties such as zeta potential, surface charge density, and surface conductivity of polyester fibers grafted with acrylic acid and acrylonitrile were measured when cationic dye solutions were streamed through. The presence of the cationic dyes on the surface of the fibers and their specific adsorption at the carboxylic groups in the acrylic acid graft copolymer produce lowering of zeta potential. The decrease in surface charge density as the percent graft increases is due to the decrease in surface area of the fibers due to the adsorption of the cationic dyes. The same trend is observed with acrylonitrile-grafted fibers. The surface conductivity of the acrylonitrile-grafted polyester fibers increases with increase in dye concentration of the streaming solution. The results for the 27.4% grafted sample differed from those of the 7.32% and 12.1% grafts, which is indicative of the formation of a three-dimensional network causing change in both the physical structure as well as the chemical nature of the surface of the substrate.     

Individual activity coefficients of ionic species from electrochemical measurements on non-isothermal systems

While the mean ionic activity of an electrolyte may be experimentally obtained by means of procedures based on equilibrium thermodynamics, reliable values of individual ionic activities are obtainable only by using procedures in which the electrolyte is not in equilibrium. On of these procedures has been developed by Milazzo et al on the basis of electric-tension measurements of non-isothermal galvanic cells. In this paper a further development of Milazzo's procedure , valid for 1:1-valent electrolytes and at least up to 0.05M, is presented. This procedure has the advantage that it does not imply any theoretical hypothesis, being based only on two experimental conclusions concerning the heats of transfer Q^*_tot of 1:1-valent electrolytes in the concentration range up to 0.05M: the additivity rule (Q^*_tot is equal to the sum of characteristic contributions from the separate ions), and Q^*_tot depends linearly on m^{$\text{1}\text{2}$}/(1 + m^{$\text{1}\text{2}$}).     

High-Temperature Thermophysical Properties of Zirconium Carbide

An apparatus based on the method of Jain and Krishnan was developed for property measurements in the temperature range from measurable radiant emission to the thermal stability limit of metallic materials. Apparatus and experimental techniques for cylindrical specimens with length-to-diameter ratios >4 are described. The theory of the method is reviewed, practical formulations are developed, and error sources are analyzed. The following properties were determined for zirconium carbide in the range 1000° to 2500°K: thermal conductivity, spectral thermal emittance at 0.65μ spectral thermal emittance at 0.65μ as a function of time in vacuum, electrical resistivity, and total thermal emittance. A compilation of experimental values for other physical properties of ZrC is given.     

Corrosion-resistant ceramics and polymer composites based on the BaO-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-SiO<Subscript>2</Subscript> system

This paper reports on the results of investigations aimed at synthesizing ceramic materials with a high mechanical strength, as well as with high thermal and chemical resistances to corrosive media. The methods used for one-stage preparation of barite-based ceramic and polymer composites with these properties are considered.     

Frequency distributions of breaking load,tenacity, and ratio of cell wall thickness to ribbon width for single cotton fibers

Analysis of the frequency distributions of breaking load, tenacity, and ratio of cell wall thickness to ribbon width (C/R) for single cotton fibers in this study has indicated that they can all be represented by β-distributions. This suggests that a parallel model of element configurations exists in which there is a uniform distribution of elemental strengths in single cotton fibers before as well as after slack mercerization. In the case of breaking load and tenacity, the distributions are positively skewed and the skewness decreases on slack mercerization, suggesting that quite a few potentially weak places have been either completely removed or at least strengthened. The changes in C/R ratio on slack mercerization for cottons having a range of maturity have been examined and discussed. The dependence of properties such as breaking load, tenacity, and linear density on cell wall to ribbon width ratio (C/R) have also been studied.     

Structure of the BaO – Al2O3 – SiO2 System (A Review)

The results of theoretical calculations and experimental studies of the ternary system BaO – Al₂O₃ – SiO₂ in the subsolidus range at temperatures of 1200 – 1400°C are considered. Complete splitting of this system into elementary polytypes is performed, a topological graph of the relationship between these polytypes is shown, and geometrical characteristics of the binary and ternary compounds comprising this system are supplied.     

Some characteristics of a sparged agitated vessel under foaming — Mechanical control of foaming —

Foam-breaking with a rotating disk mechanical foam-breaker (MFRD) was studied for a foaming system containing a diluted detergent solution in a laboratory sparged agitated vessel. The change of the foam-breaking capacity of the MFRD by varying the air sparge rate, the working volume and the impeller speed or the disk diameter was measured. Based on these measurements, empirical equations are presented for predicting the critical foam-breaking regions of the MFRD fitted with the agitated vessel. The operational range where foam-breaking with the MFRD can be carried out effectively and economically is also discussed.     

Viscosity index. I. Evaluation of selected copolymers incorporating n-octadecyl acrylate as viscosity index improvers

Compositionally and structurally varied copolymers all containing n-octadecyl acrylate were prepared and evaluated as viscosity index improvers in a common base oil under conditions of low shear. Systems evaluated over a range of copolymer and blend composition were: copolymers of n-octadecyl acrylate with, respectively, methyl methacrylate, 2-ethylhexyl acrylate, and n-dodecyl acrylate; and homopolymers of poly(n-octadecyl acrylate), prepared with a wide range of molecular weights. Properties were compared with those of blends of commercial methacrylate copolymers (acryloids) which had been freed of their entraining liquid. Mixtures of base oil with copolymers of n-octadecyl acrylate and methyl methacrylate, compared at fixed SAE viscosities, were the most efficient of all blends studied. They had the smallest rate of change of viscosity with temperature (as measured by their ASTM slopes), particularly in the composition region of incipient polymer precipitation at room temperature. Efficiency of certain of these composition was somewhat greater than that of the acryloids. A parameter that related concentration and weight-average molecular weight was used to correlate all of the data for ASTM slope and viscosity. Empirical relations developed by using this parameter enabled rheological data to be estimated that agree within 6% of experimental values for the case of thermodynamically good base oil solvents. These data demonstrated the relatively small contributions of copolymer structure to viscosity index improvement.