Evaluation of Phase Morphology and its Impact on the Viscoelastic Response of Elastomer Blends

Filler reinforced elastomer blends play a key role in the design and optimization of high performance rubber goods like tires or conveyer belts. In most cases, a phase separated, anisotropic blend morphology develops during the last processing steps (extrusion, calendering, injection moulding), which lowers its free energy by coagulation and relaxation processes, before the morphology is frozen by cross-linking. The development of the detailed phase morphology and its influence on the high-frequency viscoelastic response, affecting e.g. friction, fracture and wear properties, is not well understood at present but of high technological and scientific interest.
Accordingly, one main objective is the physically motivated modelling and numerical simulation of the thermo-chemically driven phase separation of filled elastomer blends with realistic, microscopic input parameters obtained from independent physical measurements. Beside the chemical compatibility of the polymers and the fillers, also the effect of mechanical stress on the phase dynamics shall be investigated. In combination with elaborated experimental methods, the phase field modelling for Cahn-Hilliard and Cahn-Larché type diffusion shall be applied. The local phase field equations, considering at the end three phases, must be implemented into the isogeometric analysis, allowing for the study of complex interaction of multi-phase materials with different material characteristics. The experimental focus lies on the evaluation of thermodynamic polymer-polymer- and polymer-filler interaction parameters that govern the phase morphology and filler distribution. For the simulation of phase boundary dynamics, the collective chain mobility shall be estimated as an input parameter of the Cahn-Hilliard type dynamic equation.
A second objective is the modelling and numerical simulation of the high-frequency linear viscoelastic response of unfilled and filled elastomer blends, which shall be based on the distinct phase morphology including domain and interphase size, filler distribution and cross-linking heterogeneities. The non-linear response will be analysed in a future project.
The results of phase field simulations shall be compared to experimental investigations of phase mixture processes and numerically evaluated viscoelastic moduli shall be correlated with experimentally constructed viscoelastic master curves.
The sum of the both objectives leads to a complete numerical procedure with which it is possible to simulate the complete cycle of producing and using a new polymer blend for later engineering applications by optimizing the involved process and distinctive material parameters.

23482_ Evaluation of Phase Morphology and its Impact on the Viscoelastic Response of Elastomer Blends

Filler reinforced elastomer blends play a key role in the design and optimization of high performance rubber goods like tires or conveyor belts. In most cases, a phase separated, anisotropic blend morphology develops during the last processing steps (extrusion, calendering, injection molding), which lowers its free energy by coagulation and relaxation processes, before the morphology is frozen by cross-linking. The development of the detailed phase morphology and its influence on the high-frequency viscoelastic response, affecting e.g. friction, fracture and wear properties, is not well understood at present but of high technological and scientific interest.
Accordingly, one main objective is the physically motivated modeling and numerical simulation of the thermo-chemically driven phase separation of filled elastomer blends with realistic, microscopic input parameters obtained from independent physical measurements. Beside the chemical compatibility of the polymers and the fillers, also the effect of mechanical stress on the phase dynamics shall be investigated. In combination with elaborated experimental methods, the phase field modeling for Cahn-Hilliard and Cahn-Larché type diffusion shall be applied. The local phase field equations, considering at the end three phases, must be implemented into the isogeometric analysis, allowing for the study of complex interaction of multi-phase materials with different material characteristics. The experimental focus lies on the evaluation of thermodynamic polymer-polymer- and polymer-filler interaction parameters that govern the phase morphology and filler distribution. For the simulation of phase boundary dynamics, the collective chain mobility shall be estimated as an input parameter of the Cahn-Hilliard type dynamic equation.
A second objective is the modeling and numerical simulation of the high-frequency linear viscoelastic response of unfilled and filled elastomer blends, which shall be based on the distinct phase morphology including domain and interphase size, filler distribution and cross-linking heterogeneities. The non-linear response will be analyzed in a future project.
The results of phase field simulations shall be compared to experimental investigations of phase mixture processes and numerically evaluated viscoelastic moduli shall be correlated with experimentally constructed viscoelastic master curves.
The sum of the both objectives leads to a complete numerical procedure with which it is possible to simulate the complete cycle of producing and using a new polymer blend for later engineering applications by optimizing the involved process and distinctive material parameters.