The Destructive Dissolution of Vulcanized Rubbers

In previous work the process of destructive dissolution of vulcanized natural rubber was described, and it was shown that, in the strict absence of oxygen, a vulcanizate cannot be dissolved in a hydrocarbon medium at temperatures up to 140° C. Only in the presence of molecular oxygen does heating bring about dissolution of vulcanized rubber in the solvent, under which conditions the process proceeds along this pattern: union of oxygen with the double bonds → disintegration of the molecular chains where oxygen has combined → dissolution. if the surface area of the vulcanizate remains constant, the process takes place at a constant rate which depends on the temperature and the partial pressure of the oxygen in solution. In the following, experiments are described, the results of which show that vulcanized synthetic polymers also undergo destructive solution. The experimental method was the same as that described previously. The vulcanizates were prepared from recipes adapted to the particular synthetic rubbers. As was expected, the rate of destructive solution depends on the molecular structure of the rubbers (see Figure 1).