Some Viscosity Data for Boron Trioxide

The viscosities of four samples of pure molten boron trioxide have been measured between 267° and 443°C with a concentric cylinder viscometer. The results, representing true viscosity, range from 2.1×1011 to 2.1×105 poises and are consistent with earlier data obtained at much higher temperatures. A viscosity value in the neighborhood of 1013 to 1014 poises appears to be associated with the so-called transition region in this and other glassy, or amorphous, materials.