Rubber compositions and articles thereof

A method for mixing rubber, comprising:

• combining together an elastomer and about 0.1 phr to about 10 phr of a hydrogenated gum rosin, thereby forming an initial mixture;
• mixing the initial mixture at a temperature of about 130° C. to about 180° C., thereby forming a first stage mixture;
• combining together the first stage mixture with 0.1 phr to about 5 phr of a first accelerator and about 0.1 phr to about 5 phr a second accelerator, thereby forming an intermediate mixture;
• and
• mixing the intermediate mixture at a temperature of about 90° C. to about 110° C., thereby forming a second stage mixture;
• wherein the elastomer comprises from about 25 phr to about 75 phr of a natural rubber and from about 25 phr to about 75 phr of a synthetic elastomer;
• and
• wherein the hydrogenated gum rosin has an acid value of about 140 mg KOH/g to about 200 mg KOH/g and a softening point of about 70° C. to about 125° C.