Rasouli Sajad, Zabihi Amirreza, Fasihi Mohammad, Kharat Gholamreza Bozorg Panah
School of Chemistry, Iran University of Science and Technology (IUST), P.O. Box 16844, 3319613111 Tehran, Iran.
Compounding Laboratory, Department of Technology, Kian Tire Manufacturing Company, Tehran 401310, Iran.
ACS Omega. 2023 Aug 29;8(36):32701-32711. doi: 10.1021/acsomega.3c03548. eCollection 2023 Sep 12.
The effect of silicon nitride (SiN) 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 SiN. The properties were enhanced with the filler loading content; somehow, the composite including SiN = 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 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-SiN, an autocatalytic model based on the Kamal-Sourour model was applied on the rheometry results. The calculated kinetic parameters indicated that the thermally conductive SiN accelerated the curing reaction by ∼40%, particularly at SiN = 6 phr. After 6 phr of SiN, agglomeration of the filler particles decreased its performance.
在本工作中，研究了作为导热材料的氮化硅（SiN）对丁苯橡胶/丁二烯橡胶（SBR/BR）的力学、微观结构和物理性能以及固化反应动力学的影响。结果表明，由于SiN的存在，复合材料的拉伸、硬度和压缩性能得到改善。这些性能随着填料负载量的增加而增强；在某种程度上，含SiN = 6份/100份橡胶（phr）的复合材料具有最显著的性能，复合材料的最大应变和韧性分别提高了约15%和20%，硬度提高了近7%，压缩永久变形降低了约13%。此外，填料使交联密度（通过使用溶胀试验的Flory-Rehner方程计算）增加了7.12×10⁻³mol/g，证明了固化反应过程中聚合物链之间共价键的增加。动力学研究表明，焦烧时间和最佳固化时间分别减少了约40%和约25%。为了描述SBR/BR-SiN的固化反应动力学，基于Kamal-Sourour模型的自催化模型被应用于流变学结果。计算得到的动力学参数表明，导热SiN使固化反应加速了约40%，特别是在SiN = 6 phr时。SiN含量超过6 phr后，填料颗粒的团聚降低了其性能。
