Polymer composites containing diatomite and boron carbide that are capable to absorb thermal neutrons

Composites capable to absorb thermal neutrons have been developed on the basis of resol type matrix-bisphenol-formaldehyde oligomers, in which thermally modified natural sorbents - diatomite and boron carbide were used as fillers. In particular, we used boron carbide with a dispersion of up to 50 microns (B4C) and modified diatomite of Kisatibian origin (Georgia), of the same dispersion. To obtain the polymer matrix we used bisphenol, which contained norbornane type groups: 4,4’-(2-norbornyliden)-diphenol, 4,4’-(hexahydro-4,7-methylenindan-5-yliden)-diphenol and 4,4’-(decahydro-1,4,5,8-dimethylennaft-2-yliden)-diphenol. Oligomers were obtained through interaction of bisphenols with formaldehyde. Technological schemes and parameters have been offered for matrix and modified diatomite. Composites of various compositions have been considered. Composites which contained 40 mass% thermo-reactive oligomers revealed optimal mechanical and thermal-physical characteristics. The results of the study have shown that the composite, which does not contain a component that captures thermal neutrons, practically does not weaken the neutron flux. With an increase in the content of such a component in the samples, we observe a noticeable decrease in the flux density. It should be noted that all these composites are heat-resistant up to 400 °C.