Blends of synthetic rubbers are widely used by rubber product manufacturing industries depending on the end use and product application. The estimation of individual rubber in blends is an important aspect to characterise the correctness of the mixing process. In tyre industry, Styrene butadiene rubber/Polybutadiene rubber (SBR/BR) blend is commonly used to achieve different performance properties, particularly for passenger car tyre. Out of the different quantitative analysis techniques to characterise the blend, one of the widely used techniques Gas Chromatography-Mass Spectrometry (GC-MS) has been used to develop and later validate a method to quantify the SBR/BR blend ratio. Through this GC-MS technique detection capability is measured, with a minimum limit of detection (LOD) of 5.17% and a limit of quantification (LOQ) of 15.67% Styrene butadiene rubber (SBR) in an SBR-BR vulcanizate. It is observed that the bias percentage is highest in case of a lower SBR content sample, i.e. 11.1% while in the case of other sets, it is varying from (–)1.4% to (+)1.5%. During the recovery study, it is observed that with increasing SBR content, recovery is also improving. All requirements for a successful method validation: Accuracy, precision, selectivity, detection capability, calibration range and robustness have been carried out in this entire work.

Natural rubber (NR) is not only the main compounding ingredient used to make the majority of components of tires as well as other rubber products, as it plays a significant role in ensuring that they operate well and complies with environmental standards. The applications of NR products are limited to high temperatures due to the revision tendency of NR vulcanizate. To address these issues, the potential engagement of a carbon black (CB) coupling agent (CA) in the presence of metal oxide i.e. Zinc Oxide (ZnO) was investigated in an NR-based system. This CA has dual functionality on physicomechanical properties. CA has the ability to reduce hysteresis loss as well as improve anti-reversion properties and these properties thoroughly depend on the presence of ZnO. While ZnO was added to the master formulation, a 65% improvement in reversion properties was observed. On the other hand, while ZnO fully transferred to the final formulation, bound rubber (BR) content increased by 19%, the difference in storage modulus (ΔG’) is reduced by 22%, cure rate index (CRI) improved by 14%, loss tangent (tan δ) reduced by 18% and slightly improve in elongation at break compared to control compound. Thermo-gravimetric analysis (TGA) was engaged to understand the thermal stability and degree of purity of CA. A differential Scanning Calorimeter (DSC) was used to detect the phase transition of CA. Fourier Transform Infrared Spectrum (FTIR) was adopted to detect the presence of carboxyl and amine groups in the CA moiety. Payne effect, BR content and Transmission Electron Microscope (TEM) were employed to investigate the micro-level dispersion of CB in the natural rubber (NR) matrix.