Development of natural rubber product containing carbon black for ready using

Compounded rubber containing carbon black was prepared by direct mixing the concentrated natural rubber latex with the additives. The aqueous dispersion of the additives was prepared by ball mill for 3 hours. After the desire time, concentrated natural rubber latex was added and mixed for ½ hours. The compounded latex was coagulated by formic acid. The compounded rubber was assessed the degree of carbon black dispersion by optical microscope and scanning electron microscope. The mechanical properties-tensile strength, tear strength, modulus and hardness-of vulcanized sheets were determined. The effects of type of carbon black (N220 and 330). Amount of carbon black (25-45 phr), amount of sulfur (0.5-4 phr), amount of accelerator (MBT 0.5-2 phr), amount of accelerator activator (ZnO2 -10 phr and stearic acid 1-4 phr), and type of surfactants (SDS, Tergitol NP9 and Tergittol NP10) on the mechanical properties were studied. The results indicate that the formulations of compounded rubber showing the best mechanical properties are concentrated natural rubber latex 100 parts by dry weight, carbon black type N330 25 phr, sulfur 2 phr. MBT l phr.ZnO 5 phr, stearic acid 2 phr and Tergitol NP10 3 phr. The degree of carbon black dispersion is 5.0.