This study investigated the suitability of epoxidized vegetable oils as additives in place of aromatic processing aids and activators in natural rubber based truck tyre tread compounds. The processability and cure characteristics of the compounds and physical properties of the vulcanizates were compared with those of the standard vulcanizate, which was prepared with a standard mineral oil-Dutrex R. Epoxidation of the oils was carried out (formed in situ) using the peracetic acid method and epoxidation was confirmed using 1 H NMR and 13 C NMR spectra. Epoxidized vegetable oils (EVO) were used at a fixed dose in the compounding process as processing aids. These oils were used in the compounding process to ascertain the possibility of using them as activators and processing aids. Epoxidized palm oil (EPO) showed better processing properties, polymer filler interaction and dispersion properties and best heat resistance ability. Epoxidized sunflower oil (ESFO) can be used as an accelerator with the combination of sulphenamide to overcome the problem of reversion. Epoxidized soya bean oil (ESBO), EPO and ESFO were better alternative processing aids than petroleum based aromatic oils, which have been reported as carcinogenic. The cure characteristics and physical properties of the vulcanizate based on EPO suggested that this oil could be used as an activator in rubber compounding.

The potential of naturally available oils as additives instead of processing aids and activators in carbon black filled natural rubber was investigated in this study. Physical properties and cure characteristics of the vulcanizates containing the natural oils were compared with those of the standard vulcanizate which was prepared using an aromatic oil. Soybean oil, palm oil and sunflower oil were selected as the natural oils and used at a fixed dose (5phr) in the compounding process as processing aids. The natural oils were incorporated in the compounding process, to examine their potential as activators and processing aids simultaneously. The results indicate that soybean oil, palm oil and sunflower oil are better alternative processing aids than petroleum based aromatic oils which have been reported to be carcinogenic. In addition, palm oil has the best heat resistance ability. Further, the cure characteristics and mechanical properties of the vulcanizate based on soybean oil suggest that it could be used as a co-activator for rubber compounding.

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The objectives of this study were to develop a cost-effective, environmental-friendly, mechanochemical reclaiming process for compounded nitrile rubber (NBR) latex waste generated from the dipping and treatment plants of the glove manufacturing process and evaluate properties of reclaimed NBR and virgin NBR/reclaimed NBR blend compounds. Initially, compounded NBR latex waste containing NBR latex mixed with compounding ingredients was dried and reclaimed mechanically by varying the milling time from 0 min to 12.5 min at 2.5-min time interval. Properties such as initial plasticity, Mooney viscosity, swelling, and cross-link density of the mechanically reclaimed NBR samples were evaluated. Also, a series of mechanochemically reclaimed NBR samples were produced using urea and varying its amount from 0 phr to10 phr at 2 phr intervals and milling according to the selected milling time. The mechanochemically reclaimed NBR samples were also tested for the above properties. Finally, a reclaimed NBR sample was prepared by applying the best urea loading and the optimum milling time. Further, a series of virgin NBR/reclaimed NBR blend compounds was prepared by varying the reclaimed NBR from 0% to 70% at 10% interval. Cure characteristics of the above blend compounds were evaluated and compared with those of the 100% virgin NBR (control) compound. Initial plasticity and Mooney viscosity of mechanochemically reclaimed NBR revealed that urea is effective as a reclaiming agent for dried compounded NBR latex waste. Results in overall indicated that 5 min is the optimum milling time and 6 phr is the optimum loading of urea required to produce the best reclaimed NBR in terms of properties and energy consumption. Minimum torque and cure time of the 50:50 virgin NBR/reclaimed rubber blend compound were higher compared to the control, whereas scorch time, maximum torque, and cure rate index of the former were lower compared to the latter.

in non-uniformity of the composite and hence changes its properties. This non-uniformity could be overcome by incorporating a suitable adhesion promoter and/or a coupling agent. Although titanate coupling agents are used in this study was aimed at incorporating a CA to natural rubber (NR) and low-density polyethylene (LDPE) blend through calcium carbonate (CaCO 3 effect of CA loading on properties of the composites. In this hundred parts of polymer). CaCO 3 loading was kept constant at 20 pphp. Brabender plasticorder was used to prepare o of 60 rpm. Physico-mechanical properties were evaluated according to ISO standards. Degree of swelling and gel content and dynamic properties of the composites were investigated. composites increased with the addition of CA and showed the best properties at a CA loading of 0.7 pphp. Hardness of tensile properties and water resistance were also shown at 0.7 pphp showed better compatibility and the best properties. coupling agent.