Properties of nano-sized synthetic diamond and boron nitride filled different types of epoxy resin

The present research was carried out to compare the properties of nano-sized synthetic diamond (SD) and boron nitride (BN) filled two types of epoxy: bisphenol-A deglycidyl ether (DGEBA) (E8281) and novolac epoxy resins (D431). The filler loadings which were considered in the study were varied from 1–4 vol%. High viscosity of D431 epoxy composites improved the flexural strength, modulus and coefficient of thermal expansion (CTE) but the flow rates decreased compared to that of E8281. Filler settling due to lower viscosity of E8281 creates agglomerations and voids at the bottom of the composites which can deviate its flexural and CTE properties. SD filled epoxy composites has better flexural strength and modulus as compared to BN. This might be due to the SD filler that exhibits smaller particle size, high surface area and high modulus which significantly attributes to the improvement in physical bonding with the matrix. In general, it is concluded that 4 % of SD and BN filled D431 epoxy composites showed much better flexural strength, modulus and CTE properties if compared to E8281, and hence suitable to be used as an underfill.