  Conductor insulation is one of the key components needed to make Ag-alloy
clad Bi2Sr2CaCu2O8+x (Bi-2212/Ag) superconducting round wire (RW) successful
for high field magnet applications as dielectric standoff and high winding
current densities (Jw) directly depend on it. In this study, a TiO2/polymer
insulation coating developed by nGimat LLC was applied to test samples and a
high field test coil. The insulation was investigated by differential thermal
analysis (DTA), thermo-gravimetric analysis (TGA), scanning electron microscopy
(SEM), dielectric properties measurement, and transport critical current (Ic)
properties measurement. About 29% of the insulation by weight is polymer. When
the Bi-2212/Ag wire is full heat treated, this decomposes with slow heating to
400{\deg}C in pure O2. After the full reaction, we found that the TiO2 did not
degrade the critical current properties, adhered well to the conductor, and
provided a breakdown voltage of >100 V, which allowed the test coil to survive
quenching in 31.2 T background field, while providing a 2.6 T field increment.
For Bi-2212/Ag RW with a typical diameter of 1.0-1.5 mm, this ~15 um thick
insulation allows a very high coil packing factor of ~0.74, whereas earlier
alumino-silicate braid insulation only allows packing factors of 0.38-0.48.
