Properties and thermal neutron areal transmittance of a B4C filled thermoplastic elastomer based rubber composite

•Flexible neutron shielding composites with good dispersion of B4C are fabricated.•Microstructures, mechanical properties and 10BAD of the composites are analyzed.•Standard deviation of areal uniformity of neutron transmittance is less than 0.76%. In this paper, a kind of flexible shield for thermal neutron is fabricated through blending functional B4C powder with thermoplastic elastomer polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene(SEBS) in a banbury mixer, and weight fractions[(MB4C: MSEBS)%] of the composites are prepared as 10%, 20%, 30%, 40%, 60%, 100% respectively. B4C powders are well dispersed in the matrix of SEBS through microscopic observation, even without chemical interaction between the chemical groups of SEBS and the fillers. The elongations at break and tensile strengths of the B4C/SEBS composites deteriorate rapidly compared with the virgin sample, but it seems the tensile and tear strength could still maintain a satisfactory value suitable for preparing super flexible shields. The hardness of the composites is in the range of 15–25 HA. Based on a self developed nondestructive testing device, shielding abilities of the samples are estimated by neutron transmittance, 10B areal density, linear attenuation coefficient, and thickness of half value layer. The neutron transmittance is 71.31%–32.43% corresponding to 10B areal density ranging from 2.1873 mg/cm2 to 17.6314 mg/cm2, linear attenuation coefficient is 0.1932–0.6435 mm−1, and half value layer value is 3.59–1.08 mm. It is also proved that the neutron transmittance measured shows an exponential attenuation with the increase of 10B areal density. The most importantly, the areal uniformity of neutron transmittance, with standard deviation less than 0.76%, is validated for the achievement of excellent attenuation of thermal neutrons in all directions. Consequently, results show excellent flexible and shielding performances of the functional composites.