Presence Of B2O3 Research Articles

ChemInform Abstract: SULFOTRIOXIDATION OF PERFLUOROISOPROPYL ALKENYL ETHERS

AbstractDer Perfluorisopropylallyl‐ether (I) bildet mit Schwefeltrioxid bei Zugabe von 2 ‐ 3 Mol% Bortrioxid das Fluorsulfat (II) al‐s cis/trans‐Gemisch und das Sulton (III).

Sulfotrioxidation of perfluoroisopropyl alkenyl ethers

The reactions of perfluoroisopropyl allyl I and perfluoroisopropyl propenyl ethers with SO3 have been examined. In the presence of B2O3, (I) forms perfluoro-γ-isopropoxyallyl fluorosulfate, which is an alkylating agent.

Structure of Glasses and Melts in the Na2O·GeO2·B2O3 System

Density and viscosity results are presented for ternary Na2O·GeO2·B2O3 melts (∼600° to 1300°C) and glasses containing as much as 35 mole % Na2O. Synthetic partial molar volume models indicate a fairly broad stability region for BO4 tetrahedra in the B2O3‐rich melts. Similar models for GeO2‐rich melts reveal a more limited stability region for GeO6 octahedra. The expansion coefficient contours and viscosity isotherms confirm the volume‐based conclusions for the liquid state. The high‐temperature volume models were used to develop glass volume models that agree to within several percent of experiment. It has been concluded that the melts and glasses possess similar structures. The relatively greater compositional stability of GeO6 octahedra in the presence of B2O3 (compared to Al2O3) can be related to the smaller average number of oxygens around boron (III), at a fixed O/Ge ratio, compared to aluminum (III). Evidence is presented for a slight decrease of the thermal stability of GeO6 octahedra in the GeO2‐rich melts above about 1000°C.

EXACT NOTIONS OF FLUORINE ENAMELS

The theories of Vogt, Grunwald, Mayer and Havas, and others regarding the role of fluorine in enamels are proved by mathematical rather than chemical means to be incorrect. Fluorine is not volatilized as SiF4, but disappears during the smelting process as F2, although in the presence of B2O3 it may be volatilized as BF3. Enamel formulas should be studied by means of the “subtractive” analysis method.