With the ever increasing market demand for rubber products, those in compounding and manufacturing are tasked with the challenge of increasing output without sacrificing efficiencies.  This naturally increases the requirements of processes such as mixing, extruding, and injection molding in the rubber industry.  Manyfactorscontributetothesuccessor failureofa compound formulationtomeet therequired processing and performance criteria. The physical and chemicalproperties of the raw polymer areamong themostimportant,includingmolecularweight,molecular weightdistribution,and thedegreeof long-chain branching.  Rheological characterization is perhaps the most powerful technique for quickly and easily obtaining information about these properties, enabling process/production engineers and compounder’s invaluable information about processibility of raw polymers and processed compounds.  The talk provides insights into advanced rheological measurements both in the linear viscoelastic regime and in the nonlinear regime and the interpretation of the information from these measurements primarily related to polymer chain architecture.

The scope of the talk is to evaluate differences in polymer and rubber compounds based on molecular weight, molecular weight distribution and long chain branching using a rubber process analyzer RPA. In the first step the comparison is done based on a standard frequency sweep using different polymer samples and how differences show up compared to standard tests namely the Mooney Viscosity and the MDR Cure Curve. In the second step the linear and nonlinear response from a standard strain sweep experiment are evaluated for a series of Polymer grades like EPDM and BR with different branching.