Verification of Interactions between Silica and Epoxidized Squalene as a Model for Epoxidized Natural Rubber

Unmodified squalene (Sq) and epoxidised squalene (ESq), as models for natural rubber and epoxidised natural rubber, were mixed with silica in a reactor at 140 – 145ºC, which corresponds to the optimal mixing dump temperature of silica-filled natural rubber or epoxidised natural rubber compounds. The mixtures were prepared with and without bis-(triethoxysilylpropyl) tetrasulphide (TESPT) silane coupling agent. The bound silica in the mixtures was extracted and checked for its composition by using Fourier-transform infrared (FTIR) spectroscopy. The results indicate that Sq and ESq with the help of TESPT can chemically link to the silica surface, as the FTIR spectra of purified bound silicas show absorption peaks of hydrocarbon structures. The epoxidised squalene also produces chemical interaction with silica in the absence of TESPT, but to a lesser extent compared to the one with TESPT, as indicated by the absorption intensity. On the other hand, the silica in the Sq mixture without TESPT shows no trace of hydrocarbon, indicating that there is no noticeable chemical interaction involve

Rezepturoptimierung für kieselsäureverstärkte Naturkautschukmischungen

The rubber formulation plays a significant role in the properties of NR compounds filled with silica. In this work, the influences of various silicas, silane coupling agents and diphenylguanidine (DPG) on the properties of compounds and vulcanizates, i. e. cure characteristics, Mooney viscosity, flocculation kinetics, bound rubber content, Payne effect, tan δ at 60 °C, tensile and tear properties are investigated. The results demonstrate that compound viscosity and curing behavior, as well as vulcanizate properties of the silica-filled NR are much improved by incorporating silane coupling agents. Bis-triethoxysilylpropyltetrasulfide (TESPT) clearly gives better overall properties than the disulfide-based silane (TESPD), except for scorch safety. DPG acts as a synergist to sulfenamide primary accelerators, as well as activator for the silanization reaction. Highly dispersible (HD) silicas can significantly enhance the degree of dispersion, and so lead to higher filler-rubber interaction. As a consequence, the HD silicas provide better dynamic and mechanical properties for filled NR vulcanizates compared to conventional (CV) counterparts. The optimal quantities of both, silane coupling agent and DPG, required in the formulation are correlated to the cetyl trimethylammonium bromide (CTAB) specific surface area of the silicas. Furthermore, the results reveal that the silica structure as characterized by the dibutylphthalate (DBP) adsorption also strongly influences the reinforcing efficienc

Recovered carbon black; material characterization and in-rubber performance:Sustainable future of tire manufacturing

Carbon black is widely used as a reinforcing filler in tire industry.This project aims to recover high quality carbon black from used tires using a novel pyrolysis process. The influence of process temperature on the recovered carbon black(RCB) properties was studied. Pyrolysis was carried out using passenger car tire(PCT) feedstock at temperatures of 500°C(PCT500) and 550°C(PCT550). Material properties and in-rubber performance were compared to a reference carbonblack commonly used in tires

SUBARU and e-Merlin observations of NGC3718. Diaries of an SMBH recoil?

NGC3718 is a LINER $L1.9$ galaxy, lying at a distance of about $\sim 17.4$ Mpc away from earth and its similarities with NGC5128 often award it the name "northern Centaurus A". We use high angular resolution ($\sim100$ mas) e-Merlin radio and SUBARU NIR ($\sim170$ mas) data, to take a detailed view of the processes taking place in its central region. In order to preserve some objectivity in our interpretation, we combine our results with literature values and findings from previous studies. Our NIR maps suggest, on one hand, that towards the stellar bulge there are no large scale absorption phenomena caused by the apparent dust lane and, on the other, that there is a significant (local) contribution from hot ($\sim1000$ K) dust to the nuclear NIR emission. The position where this takes place appears to be closer to the offset compact radio emission from our e-Merlin $6$ cm map, lying offset by $\sim4.25$ pc from the center of the underlying stellar bulge. The shape of the radio map suggests the presence of one (or possibly two, forming an X-shape) bipolar structure(s) $\sim1$ ($\sim0.6$) arcsec across, which combined with the balance between the gas and the stellar velocity dispersions and the presence of hard X-ray emission, point towards effects expected by AGN feedback. We also argue that NGC3718 has a "core" in its surface brightness profile, despite the fact that it is a gas-rich galaxy and we discuss its mixed photometric and spectroscopic characteristics. The latter combined with the observed spatial and radio offsets, the relative redshift between the broad and the narrow $H{\mathrm{\alpha}}$ line, the limited star formation activity and AGN feedback, strongly imply the existence of an SMBH recoil. Finally, we discuss a possible interpretation, that could naturally incorporate all these findings into one physically consistent picture.Comment: 18 pages, 18 figures, 3 tables, accepted for publications in A&