PROMOTING INTERFACIAL COMPATIBILITY OF SILICA-REINFORCED NATURAL RUBBER TIRE COMPOUNDS BY ALIPHATIC AMINE

Recent trends in industrial and academic developments of green tyre technology

Growing natural calamities as a consequence of global warming are one of the most pondering subjects today. The exponential growth of environmental pollution due to unscientific human exploitation of natural resources is considered the prime reason for the harsh responses of nature. Researchers from various fields of industry and academia are working hard to develop and implement products/technologies that are environmentally friendly or less harmful to the ecosystem. Material researchers, specifically those working in the automobile sector are also not behind in search of green products from eco-friendly raw materials and production methods. The automobile industry is collectively responsible for around 40% of global pollution in terms of greenhouse gas emissions. Out of which around 20-30% is originating from tyre production and its end-use. In this view, tyre production from eco-friendly raw materials and technologies that have minimum hazardousness to the environment is a hot research topic today. A few products in the market with "green" tags and many are in the pipeline for the recent future. This review summarises a detailed discussion of the emerging green technologies for tyre production and depicted comprehensive data from the available literature. The paper has been drafted from a well-balanced academic and industrial point of view since the researchers from both sectors are working in harmony for a better future for green tyre technology.

ENTANGLED NETWORK INFLUENCED BY CARBON BLACK IN SOLUTION SBR VULCANIZATES REVEALED BY THEORY AND EXPERIMENT

The contribution of carbon black (CB) on changes in cross-link density (n) and physical entanglement has been quantified by swelling and uniaxial stress–strain measurements considering Mooney–Rivlin parameters. Solution SBR (SSBR) vulcanizates with varying content of high abrasion furnace (HAF) CB were studied. Rubber–filler networks increase the n values, which were determined by using Flory–Rehner and modified Guth–Gold equations by equilibrium swelling study. The Mooney–Rivlin parameter C1 was quantified using n, whereas parameter C2, representing physical entanglement, was determined for filled rubber by correlating with tensile results. The parameter C2 is monitored to be decreased with increasing CB (HAF) loading. A simple parabolic trend for physical entanglement parameter with increasing CB loading is proposed, and it shows a correlation coefficient (R2) of 0.99595. Atomic force microscopy study confirms the generation of filler networking in the rubber matrix. The current findings elucidate a way for quantifying physical network changes due to fillers in an unfilled rubber system.

ENHANCING PERFORMANCE OF SILICA-REINFORCED NATURAL RUBBER TIRE TREAD COMPOUNDS BY APPLYING ORGANOCLAY AS SECONDARY FILLER

Silica-reinforced natural rubber (NR) tire tread compounds are investigated using organoclay (OC) as secondary filler. By varying mixer temperature settings at a silica/OC ratio of 45/10 phr, dump temperatures are reached of approximately 120, 140, 150, and 160 °C. The increased dump temperature leads to a better silanization reaction resulting in lower mixing torque, Mooney viscosity, and Payne effect. The optimum mixing dump temperature was found to be around 150 °C. By varying the loadings of OC in the silica-filled NR compounds from 0 to 36 wt% relative to total filler amount, the increased OC loadings decreased the Payne effect and compound viscosities, significantly shortened scorch and cure times, and raised the tan delta at −20 and 0 °C as indications for ice traction and wet skid resistance of tire treads made therefrom. The optimum loading of OC of 9 wt% relative to total filler content shows better Payne effect, cure rate index, tan delta at −20 and 60 °C indicative for rolling resistance, and DIN (German Institute of Standardization) abrasion resistance index. The results indicate that the use of this hybrid filler may provide tires with better wet traction and lower rolling resistance and wear resistance compared with the pure silica-filled system.