Silane surface modification of boron carbide in epoxy composites

Boron carbide (BC) is a boron-rich ceramic material used as a radiation absorber for shielding parts in the nuclear industry and for particle physics experimentation. BC parts are generally manufactured using the sintering process, which tends to limit the size and shape of components and imparts high cost. Low temperature and lower pressure moulding using a BC polymer matrix composites (PMC) provides an alternative process for developing lower cost parts whilst accommodating increased complexity of geometry and size. However, a lack of adhesion exhibited between BC and the resin led to a composite with limited mechanical strength and durability. In this study a silane coupling agent was used to improve the adhesion between the epoxy resin and BC. An improvement in mechanical strength was observed in the treated composite by means of three-point bending, Iosipescu and double v-notch tests. Initial investigation of the surface chemistry also showed the presence of hydroxyl groups and B–O bonds, which may promote improved adhesion through silane condensation and the formation of covalent bonds.