Rasouli Sajad, Zabihi Amirreza, Fasihi Mohammad
School of Chemistry, Iran University of Science and Technology (IUST), P.O. Box 16844-13114, Tehran, Iran.
Compounding Laboratory, Department of Technology, Kian Tire Manufacturing Company, Tehran, Iran.
Sci Rep. 2023 Aug 30;13(1):14245. doi: 10.1038/s41598-023-41337-5.
Nano-silicon carbide (SiC) as a high thermal conductive material with an intrinsic thermal conductivity of ~ 490 W/m K was used to improve the cure characteristics, kinetics, and thermodynamics of curing reaction of styrene-butadiene rubber/butadiene rubber (SBR/BR) compounds. The considerations were carried out by non-isothermal differential scanning calorimetry (DSC). Results revealed that the presence of SiC shifted the peak and end temperatures of the curing peak to lower temperatures. The calculated activation energy of the curing reaction based on the Kissinger approach showed a descent from 409.8 to 93.8 kJ/mol by adding SiC from 0 to 7.5 phr (part per hundred rubber). Moreover, the obtained Gibbs free energy variation and equilibrium constant of the curing reaction proved that the reaction was absolutely forced and irreversible, which can be increasingly characterized as a one-way process. According to the results, SiC accelerated the curing reaction because of the increment of heat transfer into the compound. This phenomenon caused the increment of enthalpy variation of the vulcanization reaction, particularly at the SiC content of 5 phr. The achieved kinetic parameters via fitting an autocatalytic model based on the Sestàk-Berggren model by the Màlek method to describe the kinetics of the curing reaction indicated that the SiC filler had a catalytic effect on the curing reaction of SBR/BR-SiC, particularly after 2.5 phr of the filler.
纳米碳化硅（SiC）作为一种本征热导率约为490 W/m·K的高导热材料，被用于改善丁苯橡胶/丁二烯橡胶（SBR/BR）复合材料的硫化特性、动力学和硫化反应热力学。通过非等温差示扫描量热法（DSC）进行了相关研究。结果表明，SiC的存在使硫化峰的峰值温度和终了温度向较低温度移动。基于基辛格方法计算的硫化反应活化能显示，通过添加从0至7.5 phr（每百份橡胶中的份数）的SiC，活化能从409.8 kJ/mol降至93.8 kJ/mol。此外，所获得的硫化反应吉布斯自由能变化和平衡常数证明该反应是绝对自发且不可逆的，越来越表现为一个单向过程。根据结果，由于传入复合材料的热传递增加，SiC加速了硫化反应。这种现象导致硫化反应焓变增加，特别是在SiC含量为5 phr时。通过用马莱克方法基于塞斯塔克 - 伯格伦模型拟合自催化模型来描述硫化反应动力学所获得的动力学参数表明，SiC填料对SBR/BR - SiC的硫化反应具有催化作用，特别是在填料含量达到2.5 phr之后。
