Vegetable oil extended emulsion styrene butadiene rubbers for passenger car radial tire tread application

Abstract

Currently emulsion polymerized Styrene Butadiene Rubber (E-SBR) is extended with various petroleum based mineral oils like Distillate Aromatic Extract (DAE), Treated Distillate Aromatic Extract (TDAE), Residual Aromatic Extract (RAE) and Naphthenic oils. It is obvious that introduction of vegetable oil should result in almost zero Polycyclic Aromatic Content (PCA) content and therefore, are environmentally friendly, renewable, and sustainable. In the present work, vegetable oil extended Styrene Butadiene Rubber (OE-SBR) were characterized for chemical properties and found that all the properties were meeting the specification requirements of mineral oils extended grades. These rubbers were also evaluated in standard Passenger Car Radial (PCR) tire tread compound recipe for various processing, different vulcanizate and other performance properties. The developed grades with vegetable oils required less mixing energy (around 10% for master batch and 15% for final batch) and shown better flow behavior (around 15% power law index and 20% activation energy reduction), better carbon dispersion (around 20%), high reinforcement index (around 15%), better rubber-filler interaction parameter (around 20%), better abrasion resistance (around 20%) and lower tanδ value @60°C (around 15%) as compared to TDAE oil extended SBR based compound. This may help to improve life of a PCR tire and reduction in fuel consumption of the vehicle.

Use of vegetable oils as an alternate to naphthenic oil for extension of emulsion styrene butadiene rubber

“…This rubber-filler interaction is improved due to presence of additional functional groups in the vegetable oils. 24…”

“…Liquid phase NMR for naphthenic oil and vegetable origin oils were reported in an earlier publication by the same authors. 24…”

“…were reported in an earlier publication by the same authors. 24 SBR extension with oils at laboratory scale and their physico-chemical characterization SBR latex was extended with various oils (shown in Table 2) and their detailed characterizations like Total extractables (ASTM D5774) using acetone, Bound styrene content using Abbemat 300 Refractometer from M/s Anton Paar (ASTM D5775), Density using Bulk Density Tester model RD3000 from M/s MonTech, Germany (ASTM D297), Mooney viscosity using MV2000E (ASTM D1646), Moisture content using Halogen Moisture Analyzer, Degradation study using Thermo Gravimetry Analyzer, TGA-Q50 and Glass transition temperature (Tg) using Differential Scanning Calorimetry, DSC-Q20 were reported in an earlier publication by the same authors. 24…”

“…This is due to presence of more olefinic content in these vegetable oils. 24 For better comparison of rubber or any other ingredients in standard recipe, it is better to match compound torque/modulus first by adjusting filler, oil and curatives dosage. So, higher dosage (15 to 25%) of curatives (sulfur and accelerator) was used for compounds prepared with vegetable oil-based SBR's (except NO_6 and NO_10) to achieve similar delta torque value.…”