The effect of B4C addition on the shielding properties of polydimethylsiloxane-novolac composite

This research aims to make a polymer composite of polydimethylsiloxane (PDMS)/Novolac base reinforced by B₄C particles. The hot press method was used to produce a polymer composite with an optimum ratio of 85/15 PDMS/Novolac and 7, 12, 15, 20, and 30% B₄C. The impact of variation in the set values of B₄C concentration on the physical, mechanical, and shielding properties of polymer composite was examined through a variety of analytical techniques, including thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), hardness testing, tensile bending strength testing, Fourier transform infrared spectroscopy (FTIR), neutron radiography, and scanning electron microscopy (SEM). The mechanical properties findings revealed that the B15 sample with a concentration of 15% wt. B₄C had the highest hardness, tensile and bending strength, which were 109 shore A, 203 MPa, and 74 MPa, respectively. Additionally, the SEM images exposed the equilibrium between porous structure and agglomeration of B₄C particles in B15 sample. Besides, adding 15-20% B₄C increased shielding properties by 9-10%. Moreover, the results of TGA demonstrated better thermal stability of polymer composites, with weight loss of less than 30% at 500 °C after adding up to 30% B₄C.