A Comprehensive Study on the Effect of Highly Thermally Conductive Fillers on Improving the Properties of SBR/BR-Filled Nano-Silicon Nitride
Sajad Rasouli, Amirreza Zabihi, Mohammad Fasihi, Gholamreza Bozorg Panah Kharat
Abstract
High Resolution Image Download MS PowerPoint Slide The effect of silicon nitride (Si 3 N 4 ) as a thermally conductive material on the mechanical, microstructural, and physical properties as well as kinetics of the curing reaction of styrene-butadiene rubber/butadiene rubber (SBR/BR) was investigated in this work. The results showed an improvement in tensile, hardness, and compression features of the composite due to the presence of Si 3 N 4 . The properties were enhanced with the filler loading content; somehow, the composite including Si 3 N 4 = 6 parts per hundred (phr) had the most significant performance, an increase of ∼15 and 20% in the maximum strain and toughness of the composite, respectively, an increase of almost 7% in the hardness, and an ∼13% reduction in the compression set. Also, the filler led to an increase in the crosslink density (calculated via the Flory–Rehner equation using swelling test) by 7.12 × 10 –5 mol/g, proving the increment of the covalent bonds between the polymer chains during the curing reaction. The kinetic consideration revealed a reduction in the scorch and optimum curing times by ∼40 and ∼25%, respectively. In order to describe the kinetics of curing reaction of SBR/BR-Si 3 N 4, an autocatalytic model based on the Kamal–Sourour model was applied on the rheometry results. The calculated kinetic parameters indicated that the thermally conductive Si 3 N 4 accelerated the curing reaction by ∼40%, particularly at Si 3 N 4 = 6 phr. After 6 phr of Si 3 N 4, agglomeration of the filler particles decreased its performance.