Practical and theoretical study of solubility of curatives in SBR, NBR and EPDM rubber
Rui Guo, Elastomer Technology & Engineering, University Twente
The distribution and dispersion of curatives (curing agents and accelerators) in rubber blends is related to their solubility in the different rubber phases. Therefore, the knowledge of their solubility is beneficial for the prediction of the performance of rubber blends. In this study the solubility of sulphur and several accelerators: N-cyclohexylbenzothiazole-2-sulphenamide (CBS),N-dicyclohexylbenzothiazole- 2-sulphenamide (DCBS), and 2-mercaptobenzothiazole (MBT) is measured in slightly with dicumyl-peroxide vulcanised Styrene-Butadiene rubber (SBR), Acrylonitrile- Butadiene rubber (NBR) and Ethylene-Propylene-Diene rubber (EPDM) at room temperature and at 60oC. The experimental results can be correlated to the calculated solubility parameters , as determined using the method of Hoftijzer and van Krevelen. Results of are used to judge the solubility of curatives in a specific component in blends of different rubbers.