Preparation and properties of novel polyhydrazides

A new class of polyhydrazides having aromatic as well as aliphatic units has been synthesized by low-temperature solution polycondensation from equimolar amounts of diacid chloride and dihydrazides in HMPT as solvent. These polyhydrazides have poor solubilities and their intrisnsic viscosities ranged from 0.2 to 0.6 dl/g. X-ray diffractograms of these polyhydrazides show that the polymers having terephthalic acid dihydrazide unit were more crystalline and all the polymers have densities in the range of 1.2-1.8 g/cm³. Thermogravimetric analysis of these polyhydrazides showed initial weight losses commencing at 220–300°C in both air and nitrogen.     

Application of Carbowax 20M as an open-tubular liquid phase in analyses of nutritionally important fats and oils.

In the first part, the reasons for the choice of Carbowax 20M-terephthalic acid as a liquid phase are indicated and the technique for preparation of columns is descirbed. The ECL of 14 to 24 carbon fatty acids (branched and positional isomers of unsaturated acids) as well as the accuracy of determination of some fatty acids, are presented. In the second part, examples of chromatograms are given as well as tables concerning the composition of various fats: vegetable oils, depot fats, and fats from organs of monogastric species, polygastric species, and fish.     

Peculiarities in the copolymerization of trioxane and epichlorohydrin under the influence of EtB⊖F3 A⊕lEt2

This study deals with the copolymerization of trioxane (TO) and 1-chloro-2, 3-epoxypropane (epichlorohydrin, ECH) catalyzed by EtB^?F₃ A^⊕lEt₂ in toluene. The rate of exhaustion of monomers during copolymerization was measured by gas chromatography. It was established that no homopolymers were formed. The copolymers obtained show a high alkali resistance, indicating a statistical distribution of the ECH in the polymer chain. During the first stages of the copolymerization the ECH is exhausted almost instantaneously, whereas TO is gradually exhausted, finally reaching a certain equilibrium depending both on the quantity of the initial ECH and on the temperature at which the process was carried out. Copolymerization is inhibited at increased ECH levels, and only homopolymerization occurs at a certain critical concentration of ECH.     

Approximate empirical formula for X-ray intensity in radioactive nuclides

Known intensities of X-rays emitted from radioactive nuclides have been plotted against atomic number, and a distinct correlation has been found only for EC-decay type nuclides, as follows: 2.75 Z^1.06>X>0.507 Z^1.06, and X_{most probable}=1.18 Z^1.06, where X is the absolute percentage and Z is the atomic number of the decay product.