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ABSTRACT:The toughening enhancement of Polyamide 6 blended with different types of functionalized elastomers was studied. Morphological analysis by scanning electron microscopy (SEM) were performed on undeformed samples in order to determine particle-size distribution. Yet more SEM examination of the damage zone ahead of notch tip in uniaxial tensile test provided insight into the failure mechanisms. The best impact strength was achieved with the PA6/EPDM-g-MA (terpolymer ethylene-propylene-diene monomer grafted with Maleic Anhydride) blend, unlike ULDPE-g-MA (ultra-low-density polyethylene grafted with maleic anhydride), which possesses the poorest toughening efficiency even though opposite results would be expected from particle-size evaluation. The higher cavitation resistance of EPDM compared to UL-DPE observed during low strain rate tensile test plays a crucial role in understanding the best performances of its blends.

Vol. 80 bands in the visible region of the spectrum is larger for the cis isomer20 tends to confirm the assignment being suggested; the area under the cis curve is -~5% greater than the area under the trans curve.The Equilibrium, ty?-Cr(OH2)4Cl2+ = trans-Cr(OH2)4Cl2+.-Measurement of the absorbancies of all of the eluent portions at the two wave lengths, 450 and 635 µ, allows the calculation of the total

REACTIONS OF GRIGNARD REAGENTS WITH SCHIFF RASES 6571 hr. at room temperature and then for 15 min. at 40°. The mixture was nearly elear at this time. A slight vacuum was applied to remove hydrogen chloride and the resulting solution of the imino chloride was cooled to 15°. A solution of hydrazoic acid (330 ml.; 5.5% or 0.424 mole) was added dropwise from a funnel replacing the dry port. A slight vacuum was maintained on the system to prevent escape of hydrazoic acid to the hood and room. The mixture was stirred at 25°for 2 hr. and under reflux (no vacuum) for 3 hr. The benzene was removed by distillation (under reduced pressure) and the residue treated with 100 ml. of water and sufficient sodium hydroxide to make alkaline (pH 8.5). The resulting solid was filtered by suction and washed with water. There was obtained 27.9 g. of crude product, m.p. 113.6-118.0°; on three reerystallizations from benzene the melting point was still not sharp. It was suspected that there was unreacted amide present (in these compounds mixed melting points rarely show depression), and the total crude material was boiled under reflux in 400 ml. of 10% sulfuric acid. This gave a product free of amide, m.p. 118.8-120.3°, from benzene.In the preparations of the other new tetrazoles similar purifications were followed. The data for these compounds are in Table II. W. Lafayette, Ind.