The Oil Stability Index Analysis method was subjected to a fifteen‐laboratory collaborative study in which the participants used currently available commercial and home‐built instruments to provide data to support the approval process as an Official Method of the American Oil Chemists’ Society. The overall average coefficient of variation was 11.3% for samples from 7 to 80 h of stability testing at 110°C.

SynopsisThe preparation, analysis, testing, and structure determination of ultrahigh impact rubbertoughened polycaprolactams (nylon 6) are described. Partially unsaturated hydrocarbon rubbers were used for this purpose. They were functionalized by reaction either in solution or in bulk with maleic anhydride to give rubbery "ene" adducts containing varying amounts of pendent succinic anhydride. Tough, rigid, thermoplastic engineering resins with notched Izod impact strengths of 750-1000 J/m were prepared by briefly melt-blending these adducts with nylon 6. Properties of the blends could be affected by the type and amount of elastomer used, the anhydride content, the type of nylon, the mixing conditions and the test conditions. Fractionation by coacervation in m-cresol/cyclohexane of a typical resin containing 20% by weight of functionalized rubber showed approximately 35% of a rubber-nylon graft, along with a few percent of free rubber dispersed in the nylon 6 matrix. A comb-block copolymer structure for the graft and a model for its formation are proposed, consistent with analyses of the fractions. Some of the blends prepared with partially hydrogenated medium vinyl polybutadiene-maleic anhydride adducts displayed a retention of impact properties at low temperatures which was superior to that obtainable with a similarly prepared EPDM-modified nylon 6. Transmission electron microscopy of a blend containing an anhydride-modified hydrogenated medium vinyl polybutadiene showed a morphology consisting of a nylon matrix containing finely dispersed, irregularly shaped, 0.03-0.55 pm rubber domains in which were found even smaller domains of nylon. INTRODUCTIONIn the unmodified state polycaprolactam, nylon 6, resin has a sufficient combination of good tensile and flexural properties, high heat distortion temperature, and an appreciable notched Izod impact strength on the order of 50 J/m that it is considered to be among the first "engineering resins." By chemically grafting the nylon to a dispersed rubber, heterophase blends with impact strengths on the order of lo00 J/m, well in exces of so-called "high impact" resins, can be obtained, and the blends might be more properly named " ultra-high impact" resins.Toughened blends of nylon 6 were prepared in 1974 by Ide and Hasegawa,' who recognized that the dispersion of polypropylene in nylon 6 was improved when the PP was first functionalized by grafting with maleic anhydride. They 2332LAWSON, HERGENROTHER, AND MATLOCK attributed this to the presence of an interfacial agent which was formed through the reaction of the anhydride with amine chain ends. The impact strengths of their blends approached ca. 250-325 J/m. Blends of nylon 6 and rubber which show toughening have been described by Cimmino et a1.,2 Martuscelli et al.,3 and G r e~o .~ In these reports, the blends were prepared from nylon 6 and an EPM copolymer grafted with maleic anhydride in the presence of peroxide; in some cases the blends were prepared by the in s i b polymerization of caprolactam in the presence of ...

A method for determining the isolated (nonconjugated)trans isomer content of fats and oils was developed using Fourier Transform Infrared Spectroscopy (FTIR), which permits automatic sample analysis and calculation of percenttrans content. Integrated band areas were used as a measure of the intensity of the band associated with thetrans C=C double bond. Measured band areas for samples with known percenttrans content were fit with a second order polynomial, resulting in a correlation coefficient of 0.99998 and a standard error of estimate of 0.11 over the range of 0 to 50%trans content. This technique also allows the analysis of neat samples, a significant improvement over current procedures in that it eliminates the need for dilution by volatile solvents and any attendant errors.

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