Procedure for Estimating Oil 3-D Solubility Parameters

Process oils make important contributions to nearly every compound in a tire, and oil/polymer interactions affect compound processing and performance.  One way to predict oil/polymer interactions is to determine the Hansen 3-D solubility parameters (HSPs) for both oil and polymer, and the polymer solubility sphere (PSS) radius.  Favorable oil/polymer interactions occur when an oil’s HSPs are located within a PSS.  Interactions are stronger when an oil’s HSPs are located closer to the center of the PSS.  If an oil’s HSPs are located outside a polymer’s solubility sphere, then the polymer is not soluble in the oil as a result of insufficient favorable interactions.  A polymer characterization technique for determining the HSPs is established called the bitumen solubility model (BISOM) method.  However, no known procedure has previously been documented for simply estimating the three HSPs for an oil.  The oil solubility parameters estimation procedure (OSPEP) has been developed to meet this need.  This procedure can provide an estimation of oil HSPs by running two titrations and a dynamic scanning calorimetry (DSC) test.  Analysis involves an iterative procedure to estimate the three HSPs for the oil.  OSPEP represents a step forward to easily obtain insight into oil/polymer interactions.