1967 Volume 40 Issue 2 Pages 91-99
NR or SBR latex was mixed with acrylonitrile (AN) by using emulsifiers and was irradiated with gamma rays. Hundreds of grams of rubbers with different grafting ratios were thus produced. Two emulsifying procedures, i. e., (i) adding AN to the latex which contains the emulsifier in advance (ii) adding a mixture of AN and emulsifier to the latex, were adopted. The grafting effect on physical properties of grafted rubbers, their stocks and vulcanizates is greater when produced by the procedure (ii) than by the procedure (i). On the other hand, NBR was blended with NR or SBR. The AN contents of blended rubbers were made equal to those of the grafted rubbers. Some physical properties of blended rubbers, their stocks and vulcanizates vary in approximate proportion to blending ratio. In contrast, these properties of grafted rubbers, stocks and vulcanizates make sudden changes with increasing grafting ratio. The vulcanizates from grafted polymers have, in general, higher resilience and lower oil resistance than those from the corresponding blended polymers.
